Search

STUDY QUESTION Do the genetic determinants of idiopathic severe spermatogenic failure (SPGF) differ between generations? SUMMARY ANSWER Our data support that the genetic component of idiopathic SPGF is impacted by dynamic changes in environmental exposures over decades. WHAT IS KNOWN ALREADY The idiopathic form of SPGF has a multifactorial etiology wherein an interaction between genetic, epigenetic, and environmental factors leads to the disease onset and progression. At the genetic level, genome-wide association studies (GWASs) allow the analysis of millions of genetic variants across the genome in a hypothesis-free manner, as a valuable tool for identifying susceptibility risk loci. However, little is known about the specific role of non-genetic factors and their influence on the genetic determinants in this type of conditions. STUDY DESIGN, SIZE, DURATION Case-control genetic association analyses were performed including a total of 912 SPGF cases and 1360 unaffected controls. PARTICIPANTS/MATERIALS, SETTING, METHODS All participants had European ancestry (Iberian and German). SPGF cases were diagnosed during the last decade either with idiopathic non-obstructive azoospermia (n = 547) or with idiopathic non-obstructive oligozoospermia (n = 365). Case-control genetic association analyses were performed by logistic regression models considering the generation as a covariate and by in silico functional characterization of the susceptibility genomic regions. MAIN RESULTS AND THE ROLE OF CHANCE This analysis revealed 13 novel genetic association signals with SPGF, with eight of them being independent. The observed associations were mostly explained by the interaction between each lead variant and the age-group. Additionally, we established links between these loci and diverse non-genetic factors, such as toxic or dietary habits, respiratory disorders, and autoimmune diseases, which might potentially influence the genetic architecture of idiopathic SPGF. LARGE SCALE DATA GWAS data are available from the authors upon reasonable request. LIMITATIONS, REASONS FOR CAUTION Additional independent studies involving large cohorts in ethnically diverse populations are warranted to confirm our findings. WIDER IMPLICATIONS OF THE FINDINGS Overall, this study proposes an innovative strategy to achieve a more precise understanding of conditions such as SPGF by considering the interactions between a variable exposome through different generations and genetic predisposition to complex diseases. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the "Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI 2020)" (ref. PY20_00212, P20_00583), the Spanish Ministry of Economy and Competitiveness through the Spanish National Plan for Scientific and Technical Research and Innovation (ref. PID2020-120157RB-I00 funded by MCIN/ AEI/10.13039/501100011033), and the 'Proyectos I+D+i del Programa Operativo FEDER 2020' (ref. B-CTS-584-UGR20). ToxOmics-Centre for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, is also partially supported by the Portuguese Foundation for Science and Technology (Projects: UIDB/00009/2020; UIDP/00009/2020). The authors declare no competing interests. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

BACKGROUND: Because of the common use of ICSI and the potential genetic aetiology of spermatogenic failure, concern has been raised about transmitting genetic disorders to ICSI offspring. However, to date, in only ∼15% of all cases of spermatogenic failure, an underlying genetic cause can be identified. We have previously established an association between spermatogenic failure and chromosomal region 11p15. In this study, we set out to explore whether NALP14, a gene recently mapped to 11p15, has a function in spermatogenesis and whether mutations in NALP14 can cause spermatogenic failure. METHODS: We applied two different multiple tissue northern (MTN) blots to determine tissue specificity of NALP14 and performed immunohistochemistry on human testis with anti-NALP14 antiserum. To determine imprinting status of NALP14, we tested the expression pattern of two single-nucleotide polymorphisms (SNPs) in human testis. Finally, we performed a mutation screen of the NALP14 gene in 157 men with azoospermia or severe oligozoospermia by direct sequencing; 158 normospermic men served as controls. RESULTS: NALP14 was, as are the three other genes in 11p15, exclusively expressed in testis. Within the testis, the NALP14 protein was mainly expressed in A dark spermatogonia, mid and late spermatocytes and spermatids. The mutation screen revealed five mutations that occurred only in the patient group. One of these unique mutations introduced an early stop codon in the NALP14 sequence, predicted to result in a severely truncated protein. CONCLUSION: Our data suggest that NALP14 has a function in spermatogenesis and that mutations in this gene might cause spermatogenic failure. [ABSTRACT FROM AUTHOR]

BACKGROUND: DAZ gene family is crucial for human spermatogenesis that requires the precise co-ordination of cell cycle events. CDC25A is recognized as the downstream substrate of DAZ gene family and is thought to function on the M-phase regulation of cell cycles. We investigated the expression profiles of CDC25A in the testes of infertile men and evaluated the relationship between CDC25A levels and testicular phenotype, clinical hormonal parameters and sperm retrieval results. METHODS: The protein and mRNA transcript levels of CDC25A in the testes of 40 azoospermic men were determined by immunohistochemistry and quantitative real-time-PCR. CDC25A in human spermatozoa was investigated by western blotting and immunofluorescence staining. RESULTS: The CDC25A protein was expressed mainly in spermatocyte, spermatid and spermatozoa. CDC25A transcript levels were significantly decreased (P = 0.0009) in patients with spermatogenic failure, especially in men with meiotic arrest and Sertoli cell-only syndrome. Significantly higher CDC25A transcript levels were detected in patients with successful sperm retrieval than in patients with failed sperm retrieval (P = 0.005). CONCLUSIONS: Decreased CDC25A is associated with spermatogenic failure and failed sperm retrieval in infertile men. Further studies are necessary to explore the functional roles of CDC25A in human spermatozoa. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sertoli cells nurse germ cells during spermatogenesis, and alterations of Sertoli cell functions have been suggested in cases of spermatogenic failures. METHODS: In this work, we measured stem cell factor (SCF) and clusterin mRNA levels, by quantitative RT–PCR, in RNA extracted from testicular biopsies of 49 azoospermic patients classified according to testicular histology as having normal spermatogenesis or spermatogenic failure. RESULTS: When related to the percentage of Sertoli cells counted on a histological section of a neighbouring tissue sample, SCF and clusterin mRNA levels were significantly lower in the ‘spermatogenic failure’ group compared with the control group (P = 0.0297 and P = 0.0043, respectively). These levels were also significantly lower in the cases of ‘constitutive’ (cryptorchidism and Yq microdeletion) and ‘idiopathic’ spermatogenic failures when compared with the control group; conversely, they were not significantly decreased in the group with ‘acquired spermatogenic failure’ (orchitis, testicular traumatism, chemoradiotherapy and varicocele). CONCLUSIONS: These data further demonstrate an alteration of Sertoli cell functions in some human spermatogenic failures and suggest that a lack of Sertoli cell maturation may be involved in cases of constitutive or idiopathic spermatogenic failures. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reciprocal translocations are often associated with infertility in male carriers. However, some carriers present normal semen profiles and are identified because of repetitive pregnancy failures. METHODS: Here, we report two different cases of reciprocal translocations. The first patient carried a t(10;14) and was normozoospermic. The second patient carried a t(13;20) and was azoospermic. Synaptonemal complexes from both carriers were analysed using immunocytogenetic techniques and multi-centromere fluorescent in situ hybridization (cenM-FISH). RESULTS: Associations between the quadrivalent and the sex body or other autosomes were seen only in the t(13;20) carrier. Heterosynapsis was observed only in the t(10;14) carrier. Synaptic pairing abnormalities were seen in 71% of the spreads in the t(13;20) carrier and 30% of the spreads in the t(10;14) carrier. Recombination frequency was decreased in the t(13;20) carrier, but not in the t(10;14) carrier. CONCLUSIONS: By comparing these two different translocation carriers with different fertility outcomes, we discuss the possible mechanisms by which translocations might cause the spermatogenesis process to fail. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Do copy-number variations (CNVs) in the azoospermia factor (AZF) regions and monogenic mutations play a major role in the development of isolated (non-syndromic) non-obstructive azoospermia (NOA) in Japanese men with a normal 46, XY karyotype? SUMMARY ANSWER Deleterious CNVs in the AZF regions and damaging sequence variants in eight genes likely constitute at least 8% and approximately 8% of the genetic causes, respectively, while variants in other genes play only a minor role. WHAT IS KNOWN ALREADY Sex chromosomal abnormalities, AZF-linked microdeletions, and monogenic mutations have been implicated in isolated NOA. More than 160 genes have been reported as causative/susceptibility/candidate genes for NOA. STUDY DESIGN, SIZE, DURATION Systematic molecular analyses were conducted for 115 patients with isolated NOA and a normal 46, XY karyotype, who visited our hospital between 2017 and 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS We studied 115 unrelated Japanese patients. AZF-linked CNVs were examined using sequence-tagged PCR and multiplex ligation-dependent probe amplification, and nucleotide variants were screened using whole exome sequencing (WES). An optimized sequence kernel association test (SKAT-O), a gene-based association study using WES data, was performed to identify novel disease-associated genes in the genome. The results were compared to those of previous studies and our in-house control data. MAIN RESULTS AND THE ROLE OF CHANCE Thirteen types of AZF-linked CNVs, including the hitherto unreported gr/gr triplication and partial AZFb deletion, were identified in 63 (54.8%) cases. When the gr/gr deletion, a common polymorphism in Japan, was excluded from data analyses, the total frequency of CNVs was 23/75 (30.7%). This frequency is higher than that of the reference data in Japan and China (11.1% and 14.7%, respectively). Known NOA-causative AZF-linked CNVs were found in nine (7.8%) cases. Rare damaging variants in known causative genes (DMRT1 , PLK4 , SYCP2, TEX11 , and USP26) and hemizygous/multiple-heterozygous damaging variants in known spermatogenesis-associated genes (TAF7L , DNAH2 , and DNAH17) were identified in nine cases (7.8% in total). Some patients carried rare damaging variants in multiple genes. SKAT-O detected no genes whose rare damaging variants were significantly accumulated in the patient group. LIMITATIONS, REASONS FOR CAUTION The number of participants was relatively small, and the clinical information of each patient was fragmentary. Moreover, the pathogenicity of identified variants was assessed only by in silico analyses. WIDER IMPLICATIONS OF THE FINDINGS This study showed that various AZF-linked CNVs are present in more than half of Japanese NOA patients. These results broadened the structural variations of AZF-linked CNVs, which should be considered for the molecular diagnosis of spermatogenic failure. Furthermore, the results of this study highlight the etiological heterogeneity and possible oligogenicity of isolated NOA. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by Grants from the Japan Society for the Promotion of Science (21K19283 and 21H0246), the Japan Agency for Medical Research and Development (22ek0109464h0003), the National Center for Child Health and Development, the Canon Foundation, the Japan Endocrine Society, and the Takeda Science Foundation. The results of this study were based on samples and patient data obtained from the International Center for Reproductive Medicine, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan. The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

BACKGROUND The molecular basis of human testicular dysfunction is largely unknown. Global gene expression profiling of testicular biopsies might reveal an expression signature of spermatogenic failure in azoospermic men. METHODS Sixty-nine individual testicular biopsy samples were analysed on two microarray platforms; selected genes were validated by quantitative real-time PCR and immunohistochemistry. RESULTS A minimum of 188 transcripts were significantly increased on both platforms. Their levels increased with the severity of spermatogenic damage and reached maximum levels in samples with Sertoli-cell-only appearance, pointing to genes expressed in somatic testicular cells. Over-represented functional annotation terms were steroid metabolism, innate defence and immune response, focal adhesion, antigen processing and presentation and mitogen-activated protein kinase K signalling pathway. For a considerable proportion of genes included in the expression signature, individual transcript levels were in keeping with the individual mast cell numbers of the biopsies. When tested on three disparate microarray data sets, the gene expression signature was able to clearly distinguish normal from defective spermatogenesis. More than 90% of biopsy samples clustered correctly into the corresponding category, emphasizing the robustness of our data. CONCLUSIONS A gene expression signature of human spermatogenic failure was revealed which comprised well-studied examples of inflammation-related genes also increased in other pathologies, including autoimmune diseases. [ABSTRACT FROM AUTHOR]

STUDY QUESTION What is the functional significance of Tex13b in male germ cell development and differentiation? SUMMARY ANSWER Tex13b regulates male germ cell differentiation by metabolic reprogramming during spermatogenesis. WHAT IS KNOWN ALREADY Studies in mice and humans suggest that TEX13B is a transcription factor and is exclusively expressed in germ cells. STUDY DESIGN, SIZE, DURATION We sequenced the coding regions of TEX13B in 628 infertile men and 427 ethnically matched fertile control men. Further, to identify the molecular function of Tex13b, we created a Tex13b knockout and conditional overexpression system in GC-1spg (hereafter, GC-1) cells. PARTICIPANTS/MATERIALS, SETTING, METHODS Our recent exome sequencing study identified novel candidate genes for male infertility. TEX13B was found to be one of the potential candidates, hence we explored the role of TEX13B in male infertility within a large infertile case–control cohort. We performed functional analyses of Tex13b in a GC-1 cell line using CRISPR-Cas9. We differentially labelled the cell proteins by stable isotope labelling of amino acids in cell culture (SILAC) and performed mass spectrometry-based whole-cell proteomics to identify the differential protein regulation in knockout cells compared to wild-type cells. We found that Tex13b knockout leads to downregulation of the OXPHOS complexes and upregulation of glycolysis genes, which was further validated by western blotting. These results were further confirmed by respirometry analysis in Tex13b knockout cells. Further, we also performed a conditional overexpression of TEX13B in GC-1 cells and studied the expression of OXPHOS complex proteins by western blotting. MAIN RESULTS AND THE ROLE OF CHANCE We identified a rare variant, rs775429506 (p.Gly237Glu), exclusively in two non-obstructive-azoospermia (NOA) men, that may genetically predispose these men for infertility. Further, we demonstrated that Tex13b functions in the transcription regulation of OXPHOS complexes. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION We examined the function of Tex13b in GC-1 in vitro by knocking out and conditional overexpression, for understanding the function of Tex13b in germ cells. Unfortunately, this could not be replicated in either an animal model or in patient-derived tissue due to the non-availability of an animal model or patient's testis biopsies. WIDER IMPLICATIONS OF THE FINDINGS This study identified that Tex13b plays an important role in male germ cell development and differentiation. The findings of this study would be useful for screening infertile males with spermatogenic failure and counselling them before the implementation of assisted reproduction technique(s). STUDY FUNDING/COMPETING INTEREST(S) Funding was provided by the Council of Scientific and Industrial Research (CSIR) under the network project (BSC0101 and MLP0113) and SERB, the Department of Science and Technology, Government of India (J C Bose Fellowship: JCB/2019/000027). The authors do not have any competing interest. [ABSTRACT FROM AUTHOR]

Study Question: What is the load, distribution and added clinical value of secondary findings (SFs) identified in exome sequencing (ES) of patients with non-obstructive azoospermia (NOA)?Summary Answer: One in 28 NOA cases carried an identifiable, medically actionable SF.What Is Known Already: In addition to molecular diagnostics, ES allows assessment of clinically actionable disease-related gene variants that are not connected to the patient's primary diagnosis, but the knowledge of which may allow the prevention, delay or amelioration of late-onset monogenic conditions. Data on SFs in specific clinical patient groups, including reproductive failure, are currently limited.Study Design, Size, Duration: The study group was a retrospective cohort of patients with NOA recruited in 10 clinics across six countries and formed in the framework of the international GEMINI (The GEnetics of Male INfertility Initiative) study.Participants/materials, Setting, Methods: ES data of 836 patients with NOA were exploited to analyze SFs in 85 genes recommended by the American College of Medical Genetics and Genomics (ACMG), Geisinger's MyCode, and Clinical Genome Resource. The identified 6374 exonic variants were annotated with ANNOVAR and filtered for allele frequency, retaining 1381 rare or novel missense and loss-of-function variants. After automatic assessment of pathogenicity with ClinVar and InterVar, 87 variants were manually curated. The final list of confident disease-causing SFs was communicated to the corresponding GEMINI centers. When patient consent had been given, available family health history and non-andrological medical data were retrospectively assessed.Main Results and the Role Of Chance: We found a 3.6% total frequency of SFs, 3.3% from the 59 ACMG SF v2.0 genes. One in 70 patients carried SFs in genes linked to familial cancer syndromes, whereas 1 in 60 cases was predisposed to congenital heart disease or other cardiovascular conditions. Retrospective assessment confirmed clinico-molecular diagnoses in several cases. Notably, 37% (11/30) of patients with SFs carried variants in genes linked to male infertility in mice, suggesting that some SFs may have a co-contributing role in spermatogenic impairment. Further studies are needed to determine whether these observations represent chance findings or the profile of SFs in NOA patients is indeed different from the general population.Limitations, Reasons For Caution: One limitation of our cohort was the low proportion of non-Caucasian ethnicities (9%). Additionally, as comprehensive clinical data were not available retrospectively for all men with SFs, we were not able to confirm a clinico-molecular diagnosis and assess the penetrance of the specific variants.Wider Implications Of the Findings: For the first time, this study analyzed medically actionable SFs in men with spermatogenic failure. With the evolving process to incorporate ES into routine andrology practice for molecular diagnostic purposes, additional assessment of SFs can inform about future significant health concerns for infertility patients. Timely detection of SFs and respective genetic counseling will broaden options for disease prevention and early treatment, as well as inform choices and opportunities regarding family planning. A notable fraction of SFs was detected in genes implicated in maintaining genome integrity, essential in both mitosis and meiosis. Thus, potential genetic pleiotropy may exist between certain adult-onset monogenic diseases and NOA.Study Funding/competing Interest(s): This work was supported by the Estonian Research Council grants IUT34-12 and PRG1021 (M.L. and M.P.); National Institutes of Health of the United States of America grant R01HD078641 (D.F.C., K.I.A. and P.N.S.); National Institutes of Health of the United States of America grant P50HD096723 (D.F.C. and P.N.S.); National Health and Medical Research Council of Australia grant APP1120356 (M.K.O'B., D.F.C. and K.I.A.); Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Inovação grant POCI-01-0145-FEDER-007274 (A.M.L., F.C. and J.G.) and FCT: IF/01262/2014 (A.M.L.). J.G. was partially funded by FCT/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES), through the Centre for Toxicogenomics and Human Health-ToxOmics (grants UID/BIM/00009/2016 and UIDB/00009/2020). M.L.E. is a consultant for, and holds stock in, Roman, Sandstone, Dadi, Hannah, Underdog and has received funding from NIH/NICHD. Co-authors L.K., K.L., L.N., K.I.A., P.N.S., J.G., F.C., D.M.-M., K.A., K.A.J., M.K.O'B., A.M.L., D.F.C., M.P. and M.L. declare no conflict of interest.Trial Registration Number: N/A. [ABSTRACT FROM AUTHOR]

Study Question: Does the hypermethylation of the maelstrom spermatogenic transposon silencer (MAEL) promoter and subsequent de-repression of transposable elements represent one of the causes of spermatogenic failure in infertile men?Summary Answer: Experimental hypermethylation of a specific region (-131 to +177) of the MAEL promoter leads to decreased expression of MAEL with increased expression of the transposable element LINE-1 (L1) and in infertile men methylation of the MAEL promoter is associated with the severity of spermatogenic failure.What Is Known Already: MAEL induces transposon repression in the male germline and is required for mammalian meiotic progression and post-meiotic spermiogenesis. Patients with non-obstructive azoospermia (NOA), defined as no sperm in the ejaculate due to spermatogenic failure, and histopathologically proven hypospermatogenesis (HS) is not uncommon and its etiology is largely unknown.Study Design, Size, Duration: Luciferase reporter assay and a targeted DNA methylation model were used to explore the effects of hypermethylation of MAEL promoter on gene expression. Germ cell-enriched testicular cells from infertile patients were used to determine the methylation levels of MAEL and expressions of MAEL and L1.Participants/materials, Setting, Methods: Twenty-six patients with histopathologically proven NOA and HS and 12 patients with obstructive azoospermia and normal spermatogenesis (NS) were enrolled in this study. Demographic and clinical information were obtained. The severity of HS was determined by a spermatogenic scoring system. The methylation levels of 26 CpGs in the MAEL promoter was measured, and quantitative real-time RT-PCR was used to determine the expressional levels of MAEL and L1.Main Results and the Role Of Chance: Targeted DNA methylation of MAEL promoter suppressed MAEL expression and de-repressed L1 activity in vitro. Patients with HS had significantly higher mean methylation levels of 26 consecutive CpGs in the MAEL promoter, compared to patients with NS. The MAEL methylation levels were negatively correlated with MAEL transcript levels and higher methylation level of MAEL was associated with severe spermatogenic defect. L1 transcript level was significantly higher in patients with HS. No differences in age, frequency of testicular insults and genetic anomalies was noted between patients with high or low MAEL methylation levels.Large Scale Data: N/A.Limitations, Reasons For Caution: Because of the difficulty in the use of human germ cells for study, the in vitro targeted DNA methylation model was performed by using human NCI-H358 cells to explore the effects of MAEL methylation on transposable elements activity. Because the germ cell-enriched testicular cells isolated from a testicular sample were relatively few, the purity of cell populations was not determined.Wider Implications Of the Findings: Measurement of the methylation level of MAEL gene may be feasible to predict the severity of spermatogenic failure or the outcome of testicular sperm retrieval.Study Funding/competing Interests: This work was supported through grants from the Ministry of Science and Technology of Taiwan (100-2314-B-006-017) and National Cheng Kung University Hospital, Tainan, Taiwan (NCKUH 20120266). The authors declare no conflicts of interest. [ABSTRACT FROM AUTHOR]

Background: Sperm extracted from testicular biopsies of azoospermic men can successfully be used for ICSI. The concern exists that testicular sperm from azoospermic men suffering from severe testicular failure may have a higher frequency of aneuploidy, which may lead to an increased risk for chromosomally abnormal offspring.Methods: Testicular sperm from patients showing spermatogenic failure (n = 17) and from patients with normal spermatogenesis (n = 26) were analysed by fluorescence in-situ hybridization (FISH). Numerical chromosomal abnormalities for chromosomes X, Y and 18 were evaluated by FISH in a total of 1697 testicular sperm derived from 43 azoospermic patients.Results: No difference was observed between the frequency of chromosomal abnormalities in testicular sperm from patients with normal spermatogenesis (5.6%) and from patients with spermatogenic failure (8.2%). However, the frequency of aneuploidy for chromosome 18 was higher in the group of azoospermic patients with spermatogenic failure than in the group with normal spermatogenesis (3.2 versus 1.3%). Within the obstructive group, sex chromosome aneuploidy (4.5%) occurred more frequently than chromosome 18 aneuploidy (1.3%; P < 0.001). Among testicular sperm derived from patients with spermatogenic failure, sex chromosomal aneuploidy (5.8%) was similar to that for chromosome 18 (3.2%).Conclusions: So far, no difference in the total frequency of chromosomal abnormalities has been observed between patients with normal spermatogenesis and patients with severe testicular failure. However, aneuploidy for chromosome 18 was higher in the group with spermatogenic failure. [ABSTRACT FROM AUTHOR]

Fertility restoration using autologous testicular tissue transplantation is relevant for infertile men surviving from childhood cancer and, possibly, in men with absent or incomplete spermatogenesis resulting in the lack of spermatozoa in the ejaculate (non-obstructive azoospermia, NOA). Currently, testicular tissue from pre-pubertal boys extracted before treatment with gonadotoxic cancer therapy can be cryopreserved with good survival of spermatogonial stem cells. However, strategies for fertility restoration, after successful cancer treatment, are still experimental and no clinical methods have yet been developed. Similarly, no clinically available treatments can help men with NOA to become biological fathers after failed attempts of testicular surgical sperm retrieval. We present a case of a 31-year-old man with NOA who had three pieces of testis tissue (each ∼2 × 4 × 2 mm3) extracted and cryopreserved in relation to performing microdissection testicular sperm extraction (mTESE). Approximately 2 years after mTESE, the thawed tissue pieces were engrafted in surgically created pockets bilaterally under the scrotal skin. Follow-up was performed after 2, 4, and 6 months with assessment of reproductive hormones and ultrasound of the scrotum. After 6 months, all engrafted tissue was extracted and microscopically analyzed for the presence of spermatozoa. Furthermore, parts of the extracted tissue were analyzed histologically and by immunohistochemical analysis. Active blood flow in the engrafted tissue was demonstrated by doppler ultrasound after 6 months. No spermatozoa were found in the extracted tissue. Histological and immunohistochemical analysis demonstrated graft survival with intact clear tubules and normal cell organization. Sertoli cells and spermatocytes with normal morphology were located near the basement membrane. MAGE-A and VASA positive spermatogonia/spermatocytes were detected together with SOX9 positive Sertoli cells. Spermatocytes and/or Sertoli cells positive for γH2AX was also detected. In summary, following autologous grafting of frozen-thawed testis tissue under the scrotal skin in a man with NOA, we demonstrated graft survival after 6 months. No mature spermatozoa were detected; however, this is likely due to the pre-existing spermatogenic failure. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Y chromosome gr/gr microdeletion eliminates two copies of the DAZ gene and several additional transcriptional units and has been associated as a risk factor for infertility. Our objective was to study the presence of the gr/gr deletion in ICSI candidates in our population and to determine whether the laboratory, clinical and ICSI outcome were different in the gr/gr deleted patients. METHODS: Two hundred and eighty-three ICSI candidates were studied. Semen analysis, serum FSH, LH, testosterone, inhibin B, karyotype and detection of sequence tagged sites in the Y chromosome were performed. RESULTS: gr/gr deletions were detected in 11 (5.07%) of 217 oligospermic and in one (1.52%) of 66 azoospermic consecutive ICSI candidates, but in none of 232 controls (P=0.002). The fertility rate was not different in the four patients of the gr/gr deleted group treated by ICSI (64.38%; 47/73) as compared to average results at our center (65.49%; 2393/3654). CONCLUSIONS: gr/gr deletions are a risk factor for spermatogenic failure at our population, but the prognosis of the four patients of the gr/gr deleted group treated by ICSI is not different from that of other ICSI patients. [ABSTRACT FROM AUTHOR]

We present a new tough-free technique for trapping, positioning and seecting human spermatozoa. This can be done in free solution (culture medium) by high-frequency electric fields. Ultramicroelectrodes fabricated by photo- and electron-beam lithography on quartz and glass substrates were used to create field cages or long field channels. If the conductivity of the external salt solution is higher than the average value of sperm cell conducitivity, negative polarization and negative dielectrophoresis occur. As a result, the induced cell polarization leads to forces repelling spermatozoa from the electrodes towards the field minimum. Using four planar electrodes a field funnel can be formed in which an individual spermatozoon is regarded while swimming. The same can be done more effectively in three-deimensional cages created by an octopole electrode system. In these systems, rapidly swimming spermatozoa could be trapped for several seconds but some spermatozoa stop moving if exposed to field strengths of more than 500 V/cm at frequencies in the MHz range. However, in stripwise and interdigitated electrodes, rapidly swimming sperm cells could be very well positioned in front of a break-electrode by a combination of electric field trapping and field induced laminar fluid streaming. This technique can be applied to bring individual spermatozoa to a defined position for characterization followed by sampling with capillaries. [ABSTRACT FROM PUBLISHER]

BACKGROUND: Testicular sperm retrieval can lead to paternity for azoospermic patients with spermatogenic failure. The human BOULE gene, a meiotic regulator of germ cells, is a gene whose altered expression may be associated with sterility. We determined the levels of BOULE transcripts in the testes of azoospermic patients, and evaluated the relationship between BOULE transcript levels and patients' testicular phenotypes, clinical parameters and sperm retrieval results. METHODS and RESULTS: BOULE transcript levels in the testes of 41 azoospermic patients were examined by quantitative competitive-reverse transcriptionpolymerase chain reaction. A significant decrease in BOULE transcript levels was detected in patients with spermatogenic failure, and BOULE transcript levels progressively decreased with increasing severity of testicular failure. BOULE transcript levels did not correlate with the serum hormone parameters measured. Significantly higher BOULE transcript levels were detected in 19 patients with successful sperm retrieval than in 12 patients with failed sperm retrieval. When using a cut-off value of 0.5 for BOULE transcript ratio to predict the success of sperm retrieval, both the sensitivity and specificity value were 100%. CONCLUSIONS: We suggest the BOULE transcript plays an important role in human spermatogenesis and that the levels may predict the presence of testicular sperm in patients with spermatogenic failure. [ABSTRACT FROM AUTHOR]

Study Question: Are exosomal microRNAs (miRNAs) in seminal plasma (SP) useful as markers of the origin of azoospermia and the presence of sperm in the testis?Summary Answer: Our study demonstrated the potential of several miRNAs contained in small extracellular vesicles (sEVs) of seminal fluid as sensitive and specific biomarkers for selecting those azoospermic individuals with real chances of obtaining spermatozoa from the testicular biopsy.What Is Known Already: There are no precise non-invasive diagnostic methods for classifying the origin of the sperm defects in semen and the spermatogenic reserve of the testis in those infertile men with a total absence of sperm in the ejaculate (azoospermia). The diagnosis of such individuals is often based on the practice of biopsies. In this context it is reasonable to study the presence of organ-specific markers in human semen that contains fluid from the testis and the male reproductive glands, which could help in the diagnosis and prognosis of male infertility. Additionally, seminal fluid contains high concentrations of sEVs that are morphologically and molecularly consistent with exosomes, which originate from multiple cellular sources in the male reproductive tract.Study Design, Size, Duration: A case and control prospective study was performed. This study compares the miRNA content of exosomes in semen samples obtained from nine normozoospermic fertile individuals (control group), 14 infertile men diagnosed with azoospermia due to spermatogenic failure, and 13 individuals with obstructive azoospermia and conserved spermatogenesis. Additionally, three severe oligozoospermic individuals (<5 × 106 sperm/ml) were included in the study.Participants/materials, Setting, Methods: A differential high-throughput miRNA profiling analysis using miRNA quantitative PCR panels was performed in SP exosomes from azoospermic patients and fertile individuals.Main Results and the Role Of Chance: A total of 623 miRNAs were included in the miRNA profiling stage of the study. A total of 397 miRNAs (63.7%) were consistently detected in samples from all groups and statistically analysed, which revealed altered patterns of miRNA expression in infertile patients. We focused on the miRNAs that were differentially expressed between azoospermia as a result of an obstruction in the genital tract (i.e. having conserved spermatogenesis) and azoospermia caused by spermatogenic failure, and described, in a miRNA validation stage of the study, the expression values of one miRNA (miR-31-5p) in exosomes from semen as a predictive biomarker test for the origin of azoospermia with high sensitivity and specificity (>90%). The efficacy of the predictive test was even better when the blood FSH values were included in the analysis. Furthermore a model that included miR-539-5p and miR-941 expression values is also described as being useful for predicting the presence of residual spermatogenesis in individuals with severe spermatogenic disorders with diagnostic accuracy.Limitations, Reasons For Caution: Further studies, with an independent second population involving a larger number of samples, are needed to confirm our findings.Wider Implications Of the Findings: Our findings contribute to the search for the most valuable genetic markers that are potentially useful as tools for predicting the presence of testicular sperm in azoospermic individuals.Study Funding/competing Interest(s): This work was financially supported by grants from the Fondo de Investigaciones Sanitarias/Fondo Europeo de Desarrollo Regional "Una manera de hacer Europa" (FIS/FEDER) [Grant number PI15/00153], the Generalitat de Catalunya [Grant number 2014SGR5412]. S.L. is sponsored by the Researchers Stabilization Program (ISCIII/Generalitat de Catalunya) from the Spanish National Health System [CES09/020]. [ABSTRACT FROM AUTHOR]

Study Question: Can Chlamydia be found in the testes of infertile men?Summary Answer: Chlamydia can be found in 16.7% of fresh testicular biopsies and 45.3% of fixed testicular biopsies taken from a selection of infertile men.What Is Known Already: Male chlamydial infection has been understudied despite male and female infections occurring at similar rates. This is particularly true of asymptomatic infections, which occur in 50% of cases. Chlamydial infection has also been associated with increased sperm DNA damage and reduced male fertility.Study Design, Size, Duration: We collected diagnostic (fixed, n = 100) and therapeutic (fresh, n = 18) human testicular biopsies during sperm recovery procedures from moderately to severely infertile men in a cross-sectional approach to sampling.Participants/materials, Setting, Methods: The diagnostic and therapeutic biopsies were tested for Chlamydia-specific DNA and protein, using real-time PCR and immunohistochemical approaches, respectively. Serum samples matched to the fresh biopsies were also assayed for the presence of Chlamydia-specific antibodies using immunoblotting techniques.Main Results and the Role Of Chance: Chlamydial major outer membrane protein was detected in fixed biopsies at a rate of 45.3%. This was confirmed by detection of chlamydial DNA and TC0500 protein (replication marker). C. trachomatis DNA was detected in fresh biopsies at a rate of 16.7%, and the sera from each of these three positive patients contained C. trachomatis-specific antibodies. Overall, C. trachomatis-specific antibodies were detected in 72.2% of the serum samples from the patients providing fresh biopsies, although none of the patients were symptomatic nor had they reported a previous sexually transmitted infection diagnosis including Chlamydia.Limitations, Reasons For Caution: No reproductively healthy male testicular biopsies were tested for the presence of Chlamydia DNA or proteins or Chlamydia-specific antibodies due to the unavailability of these samples.Wider Implications For the Findings: Application of Chlamydia-specific PCR and immunohistochemistry in this human male infertility context of testicular biopsies reveals evidence of a high prevalence of previously unrecognised infection, which may potentially have a pathogenic role in spermatogenic failure.Study Funding/competing Interest(s): Funding for this project was provided by the Australian NHMRC under project grant number APP1062198. We also acknowledge assistance from the Monash IVF Group and Queensland Fertility Group in the collection of fresh biopsies, and the Monash Health and co-author McLachlan (declared equity interest) in retrieval and sectioning of fixed biopsies. E.M. declares an equity interest in the study due to financing of fixed biopsy sectioning. All other authors declare no conflicts of interest.Trial Registration Number: N/A. [ABSTRACT FROM AUTHOR]

BACKGROUND: Partial deletions of the AZFc region of the Y chromosome were reported to be a significant risk factor for oligo-/azoospermia. In this study, we assessed the occurrence and frequency of partial AZFc microdeletions in patients with spermatogenic failure and in controls with normal spermatogenesis. METHODS: In a retrospective study design, gr/gr, b1/b3 and b2/b3 deletions were analysed by multiplex PCR in 170 men with normal spermatogenesis and 348 men with non-obstructive oligo-/azoospermia. RESULTS: gr/gr deletions were found in 14 men with oligozoospermia or azoospermia (4.0%) and in three normozoospermic men (1.8%) (NS). b1/b3 deletions were found both in controls (n=1) and in patients (n=1). b2/b3 deletions were significantly more frequent in the normozoospermic (five out of 170) than in the oligo-/azoospermic men (two out of 348). Three novel partial AZFc deletion patterns were found in four oligo-/azoospermic men. No correlation with semen or other clinical parameters was found. CONCLUSIONS: The frequency of gr/gr deletions is not significantly increased in men with oligo-/azoospermia, indicating that they are not sufficient per se to cause spermatogenetic impairment and infertility. b1/b3 and b2/b3 deletions are probably irrelevant for spermatogenesis. Novel deletion patterns found exclusively in infertile men suggest that other, still unexplored partial deletions might contribute to spermatogenic failure. [ABSTRACT FROM AUTHOR]

BACKGROUND: The human DAZ gene family includes two autosomal genes, BOULE and DAZL, and a Y-chromosomal DAZ gene cluster. All are RNA-binding proteins and assumed to be master regulators of germline gene expression. We have investigated the impact of two DAZL polymorphisms, located at nucleotide positions 260 (SNP 260) and 386 (SNP 386), on the fertility of Caucasian men. These single nucleotide polymorphisms (SNPs) have been described previously to be associated with spermatogenic failure. METHODS: Blood samples were collected and genomic DNA was extracted from 165 normozoospermic men and 202 oligo- or azoospermic patients, of whom 28 displayed an AZFc deletion. The frequencies of A or G allelic variants in SNP 260 and 386 were analysed via TaqMan allelic discrimination assays. In both cases, the A to G transition leads to a threonine to alanine change. RESULTS: A total of 24.2% of the controls showed a heterozygous nucleotide variant (AG) for the SNP 260 and the remaining 75.8% were homozygous for A. In the AZFc-deleted group, this distribution was significantly different, with 39.3% for AG, 57.1% for AA and 3.6% for GG. However, the increased heterozygosity was not correlated with sperm counts and morphology. The patients without deletions displayed a similar allelic pattern to the controls (24.1% AG/75.9% AA). For SNP 386, only the AA nucleotide variant was found in all subjects studied and in no case was the previously described heterozygous AG variant found. CONCLUSION: In a selected Caucasian population, the DAZL SNP 386 is completely absent and SNP 260 is not associated with spermatogenic failure and therefore does not represent a molecular marker for genetic diagnosis of male infertility. [ABSTRACT FROM AUTHOR]

Study Question: What is the diagnostic potential of next generation sequencing (NGS) based on a 'mouse azoospermia' gene panel in human non-obstructive azoospermia (NOA)?Summary Answer: The diagnostic performance of sequencing a gene panel based on genes associated with mouse azoospermia was relatively successful in idiopathic NOA patients and allowed the discovery of two novel genes involved in NOA due to meiotic arrest.What Is Known Already: NOA is a largely heterogeneous clinical entity, which includes different histological pictures. In a large proportion of NOA, the aetiology remains unknown (idiopathic NOA) and yet, unknown genetic factors are likely to play be involved. The mouse is the most broadly used mammalian model for studying human disease because of its usefulness for genetic manipulation and its genetic and physiological similarities to man. Mouse azoospermia models are available in the Mouse Genome Informatics database (MGI: http://www.informatics.jax.org/).Study Design, Size, Duration: The first step was to design of a 'mouse azoospermia' gene panel through the consultation of MGI. The second step was NGS analysis of 175 genes in a group of highly selected NOA patients (n = 33). The third step was characterization of the discovered gene defects in human testis tissue, through meiotic studies using surplus testicular biopsy material from the carriers of the RNF212 and STAG3 pathogenic variants. The final step was RNF212 and STAG3 expression analysis in a collection of testis biopsies.Participants/materials, Setting, Methods: From a total of 1300 infertile patients, 33 idiopathic NOA patients were analysed in this study, including 31 unrelated men and 2 brothers from a consanguineous family. The testis histology of the 31 unrelated NOA patients was as follows: 20 Sertoli cell-only syndrome (SCOS), 11 spermatogenic arrest (6 spermatogonial arrest and 5 spermatocytic arrest). The two brothers were affected by spermatocytic arrest. DNA extracted from blood was used for NGS on Illumina NextSeq500 platform. Generated sequence data was filtered for rare and potentially pathogenic variants. Functional studies in surplus testicular tissue from the carriers included the investigation of meiotic entry, XY body formation and metaphases by performing fluorescent immunohistochemical staining and immunocytochemistry. mRNA expression analysis through RT-qPCR of RNF212 and STAG3 was carried out in a collection of testis biopsies with different histology.Main Results and the Role Of Chance: Our approach was relatively successful, leading to the genetic diagnosis of one sporadic NOA patient and two NOA brothers. This relatively high diagnostic performance is likely to be related to the stringent patient selection criteria i.e. all known causes of azoospermia were excluded and to the relatively high number of patients with rare testis histology (spermatocytic arrest). All three mutation carriers presented meiotic arrest, leading to the genetic diagnosis of three out of seven cases with this specific testicular phenotype. For the first time, we report biallelic variants in STAG3, in one sporadic patient, and a homozygous RNF212 variant, in the two brothers, as the genetic cause of NOA. Meiotic studies allowed the detection of the functional consequences of the mutations and provided information on the role of STAG3 and RNF212 in human male meiosis.Limitations, Reasons For Caution: All genes, with the exception of 5 out of 175, included in the panel cause azoospermia in mice only in the homozygous or hemizygous state. Consequently, apart from the five known dominant genes, heterozygous variants (except compound heterozygosity) in the remaining genes were not taken into consideration as causes of NOA. We identified the genetic cause in approximately half of the patients with spermatocytic arrest. The low number of analysed patients can be considered as a limitation, but it is a very rare testis phenotype. Due to the low frequency of this specific phenotype among infertile men, our finding may be considered of low clinical impact. However, at an individual level, it does have relevance for prognostic purposes prior testicular sperm extraction.Wider Implications Of the Findings: Our study represents an additional step towards elucidating the genetic bases of early spermatogenic failure, since we discovered two new genes involved in human male meiotic arrest. We propose the inclusion of RNF212 and STAG3 in a future male infertility diagnostic gene panel. Based on the associated testis phenotype, the identification of pathogenic mutations in these genes also confers a negative predictive value for testicular sperm retrieval. Our meiotic studies provide novel insights into the role of these proteins in human male meiosis. Mutations in STAG3 were first described as a cause of female infertility and ovarian cancer, and Rnf212 knock out in mice leads to male and female infertility. Hence, our results stimulate further research on shared genetic factors causing infertility in both sexes and indicate that genetic counselling should involve not only male but also female relatives of NOA patients.Study Funding/competing Interest(s): This work was funded by the Spanish Ministry of Health Instituto Carlos III-FIS (grant number: FIS/FEDER-PI14/01250; PI17/01822) awarded to CK and AR-E, and by the European Commission, Reproductive Biology Early Research Training (REPROTRAIN, EU-FP7-PEOPLE-2011-ITN289880), awarded to CK, WB, and AE-M. The authors have no conflict of interest. [ABSTRACT FROM AUTHOR]

Study Question: Are infertile men with reduced semen quality at risk of a further decrease in testicular function?Summary Answer: Infertile men with severely reduced semen quality risk further deterioration of semen quality 15 years after treatment for infertility, and a lower baseline sperm concentration was associated with a more pronounced increase in LH and decrease in testosterone/LH ratio at follow-up.What Is Known Already: Male factors account for up to 50% of human infertility. The most common finding is spermatogenic failure (SgF) yet the life course of semen quality and testosterone production in such men has not been described.Study Design, Size, Duration: A follow-up study of men with SgF was performed 15 years after the initial infertility assessment between January 1995 and December 2000.Participants/materials, Setting, Methods: Hospital records were used to identify potential participants in the study. A total of 137 men with primary male infertility due to SgF and 70 controls with good semen quality from couples with female factor infertility who attended a tertiary referral centre were included: the participation rate was 31% and 26%, respectively. The men provided semen samples and underwent a physical examination. Blood samples were taken to measure levels of reproductive hormones (FSH, LH, testosterone, sex hormone-binding globulin, estradiol and inhibin B). Current results were compared with results from the initial assessments.Main Results and the Role Of Chance: At the time of follow up the SgF men had significantly lower Leydig cell capacity than the control group as well as much lower semen quality. For the SgF men, between baseline sampling and follow up, the median sperm concentration decreased from 1.9 to 0.6 mill/ml and total sperm count from 7.7 to 2.0 million (P = 0.019 and 0.012, respectively), and 10% developed azoospermia. Calculated free testosterone (cFT), but not total testosterone (tT) decreased in the SgF group by ~0.6% (95% CI 0.1-1.2%) per year. In the SgF group, LH increased by 1.6% (CI 0.9-2.3%) annually, and consequently tT/LH and cFT/LH ratios had decreased by 1.3% (CI 0.5-2.1) and 2.1% (CI 1.2-3.0%), respectively. The increase in LH and the decreases in tT/LH and cFT/LH ratios were more pronounced in men with lower baseline sperm concentrations.Limitations, Reasons For Caution: We consider the case group as representative of infertile men not in need of testosterone treatment at baseline investigation, but do not have information on those that chose not to participate in the follow-up study. There were alterations in some hormone analysis methods during the follow-up period that may introduce uncertainty in interpretation of long-term changes in hormone levels despite rigorous quality control. The validity of the control group suffers from a lack of hormone values at baseline. Also, at follow-up, for practical reasons only one semen sample could be obtained, which makes the effect estimate more uncertain and there is a risk of non-differential misclassification.Wider Implications Of the Findings: Without being able to predict individual outcomes, it is prudent to consider sperm cryopreservation or advise not to postpone fertility treatment when men present with infertility due to impaired semen quality. Whether partly compensated Leydig cell insufficiency in men with SgF will eventually develop into overt testosterone deficiency cannot be determined from our study.Study Funding/competing Interest(s): Aase and Einar Danielsen (Grant no. 10-001053), Nordic Research Committee (Grant no. 5109), The Kirsten and Freddie Johansen Fund, and Rigshospitalet's Research Fund (grant no. R24-A812). There are no competing interests. [ABSTRACT FROM AUTHOR]

Study Question: Is the thrombophilia mutation factor V Leiden (FVL) associated with an increased total sperm count?Summary Answer: Carriers of FVL have a higher total sperm count than non-FVL-carriers, which could not be explained by genetic linkage or by observations in a FVL-mouse model.What Is Known Already: FVL has a high prevalence in Caucasians despite detrimental health effects. Carriers have been shown to have higher fecundity, which might partly explain this evolutionary paradox.Study Design, Size, Duration: We determined FVL status in two cohorts (Dutch, n = 627; Danish, n = 854) of consecutively included men without known causes for spermatogenic failure, and performed an individual patient data meta-analysis of these two cohorts together with one previously published (Dutch, n = 908) cohort. We explored possible biological underpinnings for the relation between sperm count and FVL, by use of a FVL-mouse model and investigations of genetic linkage.Participants/materials, Setting, Methods: Participants were male partners of subfertile couples (two Dutch cohorts) and young men from the general population (Danish cohort): FVL carrier rate was 4.0%, 4.6% and 7.3%, respectively. There were differences in smoking, abstinence time and age between the cohorts. We corrected for these in the primary analysis, which consisted of a mixed linear effects model, also incorporating unobjectified population differences. In public haplotype data from subjects of European descent, we explored linkage disequilibrium of FVL with all known single nucleotide polymorphisms in a 1.5 MB region around the F5 gene with an R2 cutoff of 0.8. We sequenced exons of four candidate genes hypothesized to be linked to FVL in a subgroup of FVL carriers with extreme sperm count values. The animal studies consisted of never mated 15-18-week-old C57BL/J6 mice heterozygous and homozygous for FVL and wild-type mice. We compared spermatogenesis parameters (normalized internal genitalia weights, epididymis sperm content and sperm motility) between FVL and wild-type mice.Main Results and the Role Of Chance: Human FVL carriers have a higher total sperm count than non-carriers, with an adjusted mean difference of 31 × 106 (95%CI 0.2-61.7; P = 0.048). Mice with the FVL mutation do not have increased spermatogenesis as compared to wildtype mice. None of the studied polymorphisms was in linkage disequilibrium, either in the public databases or in a subgroup of FVL carriers with extremely high sperm counts.Limitations, Reasons For Caution: The difference in total sperm count would benefit from confirmation in other cohorts. The finding of higher count in carriers was consistent however, with no heterogeneity between the cohorts. The lack of effect of murine FVL might suggest there is no direct causality. The exploratory efforts on genetic linkage do not rule out that the association is a reflection of FVL co-inheritance with a non-studied causative polymorphism.Wider Implications Of the Findings: A high sperm count in FVL-carrying males contributes to understanding the high prevalence of this otherwise disadvantageous mutation. The findings might provide directions for future research on male fertility.Study Funding/competing Interest(s): No conflicts of interest. Research was conducted with funding from the Netherlands Organisation for Scientific Research (NWO, VIDI innovative research grant 016.126.364 awarded to S. Middeldorp). The Danish cohort was supported by the Innovation Fund Denmark (InnovationsFonden, grant no. 14-2013-4), The Danish Ministry of Health and the Danish Environmental Protection Agency.Trial Registration Number: Not applicable. [ABSTRACT FROM AUTHOR]

BACKGROUND: M-phase promoting factor (MPF), which is comprised of Cyclin B and a catalytic subunit, Cdc2, is a key enzyme required for cells to enter M phase in both mitosis and meiosis. MPF activity is controlled by the stimulatory dephosphorylation of the Cdc25 family and the inhibitory phosphorylation of Wee1. We determined the levels of mRNA transcripts of MPF and its regulators in the testes of infertile men, and evaluated the relationship between the transcript levels and patients’ testicular phenotypes and sperm retrieval results. METHODS AND RESULTS: The mRNA transcript levels of CDC2, CCNB1, CCNB2, CDC25A, CDC25B, CDC25C and WEE1 in the testes of 37 azoospermic patients were examined by quantitative real-time polymerase chain reaction. Significant decreases in CDC2, CCNB1, CCNB2, CDC25A, CDC25C and WEE1 mRNA transcript levels were detected in patients with spermatogenic failure. CDC2 mRNA transcript levels correlated significantly with those of CCNB1 and CCNB2 mRNA. Significantly higher CDC2, CCNB1, CCNB2, CDC25C and WEE1 mRNA transcript levels were detected in 18 patients with successful sperm retrieval than in 11 patients with failed sperm retrieval. CONCLUSIONS: We suggest that the decreased mRNA transcripts of MPF and its regulators play important roles in human spermatogenesis. [ABSTRACT FROM AUTHOR]

Study Question: Are copy number variations (CNVs) in the pseudoautosomal regions (PARs) frequent in subjects with Y-chromosome microdeletions and can they lead to abnormal stature and/or neuropsychiatric disorders?Summary Answer: Only subjects diagnosed with azoospermia factor (AZF)b+c deletions spanning to the end of the Y chromosome (i.e. terminal deletions) harbor Y isochromosomes and/or cells 45,X that lead to pseudoautosomal gene CNVs, which were associated with abnormal stature and/or neuropsychiatric disorders.What Is Known Already: The microdeletions in the long arm of the Y chromosome (Yq) that include the loss of one to three AZF regions, referred to as Yq microdeletions, constitute the most important known etiological factor for primary spermatogenic failure. Recently, controversy has arisen about whether Yq microdeletions are associated with gain or loss of PAR genes, which are implicated in skeletal development and neuropsychiatric function.Study Design, Size, Duration: We studied a cohort of 42 Chilean patients with complete AZF deletions (4 AZFa, 4 AZFb, 23 AZFc, 11 AZFb+c) from a university medical center, diagnosed over a period of 15 years. The subjects underwent complete medical examinations with special attention to their stature and neuropsychiatric function.Participants/materials, Setting, Methods: All subjects were characterized for Yq breakpoints by PCR, and for CNVs in PARs by multiplex ligation-dependent probe amplification (MLPA), followed by qPCR analysis for genes in PAR1 (SHOX and ZBED1), PAR2 (IL9R) and two single copy genes (SRY and DDX3Y, respectively located in Yp11.3 and AZFa). In addition, karyotypes revision and fluorescence in situ hybridization (FISH) for SRY and centromeric probes for X (DXZ1) and Y (DYZ3) chromosomes were performed in males affected with CNVs.Main Results and the Role Of Chance: We did not detect CNVs in any of the 35 AZF-deleted men with interstitial deletions (AZFa, AZFb, AZFc or AZFb+c). However, six of the seven patients with terminal AZFb+c deletions showed CNVs: two patients showed a loss and four patients showed a gain of PAR1 genes, with the expected loss of VAMP-7 in PAR2. In these patients, the Yq breakpoints localized to the palindromes P8, P5 or P4. In the four cases with gain of PAR1, qPCR analysis showed duplicated signals for SRY and DDX3Y and one copy of IL9R, indicating isodicentric Yp chromosomes [idic(Y)] with breakpoint in Yq11.22. The two patients who had loss of PAR1, as shown by MLPA, had an additional reduction for SRY and DDX3Y, as shown by qPCR, associated with a high proportion of 45,X cells, as determined by FISH and karyotype. In agreement with the karyotype analysis, we detected DYZ3++ and DYZ3+ cells by FISH in the six patients, confirming idic(Y) and revealing additional monocentric Y chromosome [i(Y)]. Five patients had a history of major depressive disorders or bipolar disorder, and three had language impairment, whereas two patients showed severe short stature (Z score: -2.75 and -2.62), while a man with bipolar disorder was very tall (Z score: +2.56).Large Scale Data: N/A.Limitations, Reasons For Caution: The number of males studied with Y-chromosome microdeletions and normozoospermic controls with normal karyotypes may not be enough to rule out an association between AZF deletions and PAR abnormalities. The prevalence of Y isochromosomes and/or 45,X cells detected in peripheral blood does not necessarily reflect the variations of PAR genes in target tissues.Wider Implications Of the Findings: This study shows that CNVs in PARs were present exclusively in patients with terminal AZFb+c deletions associated with the presence of Y isochromosomes and 45,X cells, and may lead to neuropsychiatric and growth disorders. In contrast, we show that men with interstitial Yq microdeletions with normal karyotypes do not have an increased risk of PAR abnormalities and of phenotypical consequences. Moreover, our results highlight the importance of performing molecular studies, which are not considered in the usual screening for patients with Yq microdeletions.Study Funding/competing Interests: This work was supported by the National Fund for Scientific and Technological Development of Chile (FONDECYT), grant no. 1120176 (A.C.). The authors declare that no conflicting interests exist. [ABSTRACT FROM AUTHOR]

Deletion of the AZFc region of the Y chromosome is the most frequent molecularly defined cause of spermatogenic failure. We report three unrelated men in whom azoospermia or severe oligozoospermia was caused by de-novo AZFc deletions, and who produced sons by intracytoplasmic sperm injection (ICSI). We employed polymerase chain reaction (PCR) assays to examine the Y chromosomes of their four infant sons. All four sons were found to have inherited the Y chromosome deletions. Such sons are likely to be infertile as adults. This likelihood should be taken into account when counselling couples considering ICSI to circumvent infertility due to severe oligozoospermia or non-obstructive azoospermia. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Are Y-chromosome microdeletions associated with SHOX haploinsufficiency, thus representing a risk of skeletal anomalies for the carriers and their male descendents? SUMMARY ANSWER The present study shows that SHOX haploinsufficiency is unlikely to be associated with Y-chromosome microdeletions. WHAT IS KNOWN ALREADY Y-chromosome microdeletions are not commonly known as a major molecular genetic cause of any pathological condition except spermatogenic failure. However, it has been recently proposed that they are associated not only with infertility but also with anomalies in the pseudoautosomal regions (PAR), among which SHOX haploinsufficiency stands out with a frequency of 5.4% in microdeletion carriers bearing a normal karyotype. This finding implies that sons fathered by men with Y-chromosome defects will not only exhibit fertility problems, but might also suffer from SHOX-related conditions. STUDY DESIGN Five European laboratories (Florence, Münster, Barcelona, Padova and Ancona), routinely performing Y-chromosome microdeletion screening, were enrolled in a multicenter study. PARTICIPANTS/MATERIALS, SETTING, METHODS PAR-linked and SHOX copy number variations (CNVs) were analyzed in 224 patients carrying Y-chromosome microdeletions and 112 controls with an intact Y chromosome, using customized X-chromosome-specific array-CGH platforms and/or qPCR assays for SHOX and SRY genes. MAIN RESULTS AND THE ROLE OF CHANCE Our data show that 220 out of 224 (98.2%) microdeletion carriers had a normal SHOX copy number, as did all the controls. No SHOX deletions were found in any of the examined subjects (patients as well as controls), thus excluding an association with SHOX haploinsufficiency. SHOX duplications were detected in 1.78% of patients (n = 4), of whom two had an abnormal and two a normal karyotype. This might suggest that Y-chromosome microdeletions have a higher incidence for SHOX duplications, irrespective of the patient's karyotype. However, the only clinical condition observed in our four SHOX-duplicated patients was infertility. LIMITATIONS, REASONS FOR CAUTION The number of controls analyzed is rather low to assess whether the SHOX duplications found in the two men with Y-chromosome microdeletions and a normal karyotype represent a neutral polymorphism or are actually associated with the presence of the microdeletion. WIDER IMPLICATIONS OF THE FINDINGS Men suffering from infertility due to the presence of Y-chromosome microdeletions can resort to artificial reproductive technology (ART) to father their biological children. However, infertile couples must be aware of the risks implied and this makes genetic counseling a crucial step in the patient's management. This study does not confirm previous alarming data that showed an association between Y-chromosome microdeletions and SHOX haploinsufficiency. Our results imply that deletion carriers have no augmented risk of SHOX-related pathologies (short stature and skeletal anomalies) and indicate that there is no need for radical changes in genetic counseling of Yq microdeletion carriers attempting ART, since the only risk established so far for their male offspring remains impaired spermatogenesis. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Italian Ministry of University (grant PRIN 2010-2012 to C.K.), Tuscan Regional Health Research Program (‘Progetto Salute 2009’) to G.F., the Spanish Ministry of Health (grant FIS-11/02254) and the European Union ‘Reprotrain’ Marie Curie Network (project number: 289880 to C.K.). The authors declare that no conflicting interests exist. [ABSTRACT FROM PUBLISHER]

Background: In spite of tremendous efforts by a number of groups, the search for single nucleotide polymorphisms (SNPs) strongly associated with male factor infertility by means of gene re-sequencing studies has yielded few likely candidates. A recent pilot, genome-wide SNP association study (GWAS) identified a list of SNPs associated with oligozoospermia and azoospermia. This is an expanded follow-up study of the SNPs identified by the GWAS as well as other SNPs from previously published gene re-sequencing studies.Methods: On the basis of the pilot GWAS and SNPs with published associations with male infertility, 172 SNPs were genotyped in men with idiopathic azoospermia or oligozoospermia using the Illumina BeadXpress platform.Results: Several SNPs were identified or confirmed to be significantly associated with oligozoospermia and/or azoospermia. More importantly, this follow-up study indicates that, at least in Caucasian men, no single common SNP accounts for a significant proportion of spermatogenic failure cases.Conclusions: The associations reported in this study are promising, but much larger genome-wide studies will be necessary to confidently validate these SNPs and identify novel SNPs associated with male infertility. [ABSTRACT FROM AUTHOR]

BACKGROUND: A specific haplotype (AGATA) in the estrogen receptor alpha (ER1) gene was recently described as a new risk factor for cryptorchidism in the Japanese population. In this ethnic group, single-nucleotide polymorphism 12 (SNP12) was concluded to be the tag SNP for the AGATA haplotype. MATERIALS AND METHODS: A large group of patients (total number = 335) and controls (total number = 567) of two Caucasian populations were analysed for the AGATA haplotype and SNP12 to verify whether this genetic variant and its tag SNP were associated with cryptorchidism or with severe spermatogenic failure. RESULTS: We confirm that SNP12 is the tag SNP for the AGATA haplotype also in Caucasians. However, in contrast with the Japanese population we found a protective effect for ESR1 SNP12 on cryptorchidism in the Italian population. No association between SNP12 and severe spermatogenic disturbances was observed. CONCLUSIONS: The observed associations (although with opposite effect) with cryptorchidism encourage future studies on independent cases and controls from different ethnic and geographic origins. On the other hand, in contrast with other ESR1 polymorphisms, SNP12 polymorphism is not associated with severe male factor infertility in two independent European population. [ABSTRACT FROM AUTHOR]

BACKGROUND: The reciprocal relationship between plasma FSH and inhibin B generally reflects the state of spermatogenesis but data in some settings indicate further complexity in their relationship. Inhibin circulates as a range of higher molecular weight (mol wt) forms of varying bioactivity such that the serum profile of inhibin forms may differ between normal men and those with varying types of spermatogenic failure. The aim of this study was to establish if the inhibin B mol wt distribution was altered in men with infertility. METHODS: The mol wt profiles of inhibin B and free α-subunit were determined in plasma of fertile (n = 11) and infertile (n = 17) men using a combined immunoaffinity chromatography, preparative SDS-PAGE and electro-elution procedure and fractions assayed using ELISAs for inhibin B, total inhibin (all forms containing the α-subunit) and free α-subunit. RESULTS: Inhibin B was identified as precursor (60-65 k) and mature (26-30 k) forms in plasma in similar proportions (29%) in fertile men and oligospermic men (25%), but was undetectable in azoospermic men. The free α-subunit detected by the pro-αC ELISA was identified as both the precursor and processed (pro-αC) forms with similar proportions in fertile (8%) and all infertile (4-14%) men. The pro-αC ELISA did not detect the precursor forms of inhibin B in plasma while the inhibin B ELISA detected all total inhibin forms following removal of pro-containing forms by immunoabsorption. CONCLUSIONS: (i) the proportions of precursor inhibin B and α-subunit forms in the circulation are unchanged in men with spermatogenic disorders indicating there is no alteration of the Sertoli cell inhibin secretory pattern; (ii) these fractionation studies indicate that pro-αC and inhibin B ELISAs specifically detect the free α-subunit and inhibin B forms present in male plasma. [ABSTRACT FROM AUTHOR]

Background: Fertility protection is an urgent clinical problem for prepubertal male oncology patients who undergo either chemotherapy or radiotherapy. As these patients do not have mature sperm to be frozen, there is as yet no effective method to preserve their fertility.Methods and Results: Single pieces of immature mouse (1.5 x 1.5 x 1.5 mm) or rabbit (2.0 x 2.0 x approximately 3.0 mm) testis were cryopreserved, thawed and transplanted into mouse testes. Histological techniques were used to determine the presence of spermatogenesis, which was restored in both mouse and rabbit testicular pieces, and led to the production of mature sperm after both cryopreservation and syngeneic or xenogeneic transplantation into mouse testes. Using sperm developed in the frozen-thawed transplants, mouse offspring were born after in-vitro microinsemination. Furthermore, rabbit offspring were obtained using rabbit sperm that developed in fresh transplants in a xenogeneic surrogate mouse.Conclusions: This approach of 'testicular tissue banking' is a promising technique for the preservation of fertility in prepubertal male oncology patients. Xenogeneic transplantation into immunodeficient mice may provide a system for studying spermatogenic failure in infertile men. [ABSTRACT FROM AUTHOR]

Although great progress has been made in both the investigation and treatment of infertility, a considerable number of patients still fail to conceive. Spermatogenic failure and/or oocyte ageing appear to be responsible for a large proportion of cases. The use of donor gametes may bring legal, ethical and even social problems of acceptance that can discourage infertile couples from the donor route. Fortunately, emerging reproductive technologies and preliminary results from animal experiments provide some hope for alternative sources of gametes through which these infertile patients can finally conceive their own genetic child. In conjunction with intracytoplasmic sperm injection (ICSI), fertilization of human oocytes with immature sperm precursors, e.g. spermatids and even secondary spermatocytes, has resulted in healthy babies. Pregnancies have also resulted from the use of spermatids derived from in-vitro spermatogenesis. In the mouse, even primary spermatocytes appear able to participate in normal embryogenesis. In view of the possibility for transplantation and even xenotransplantation of spermatogonia to a host testis in animals, a similar use of human male stem cells might provide an attractive source for the treatment of males with arrested spermatogenesis, as well as male cancer patients. Transplantation of somatic cell nuclei and their haploidization within oocytes may prove to be a practical way of eradicating age-related aneuploidy and so constitute an innovative source of healthy oocytes. Most importantly, however, the safety of the procedures described here needs to be proven before their application to the human arena. Finally, we discuss the implications of cytoplasmic quality and of genetic imprinting in the context of these manipulations. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Is it possible to identify a reliable marker of successful sperm retrieval (+SR) in men with idiopathic non-obstructive azoospermia (iNOA) undergoing microdissection testicular sperm extraction (mTESE)? SUMMARY ANSWER A higher likelihood of +SR during mTESE is observed in men with iNOA and lower preoperative serum anti-Müllerian hormone (AMH) levels, with good predictive accuracy achieved using an AMH threshold of <4 ng/ml. WHAT IS KNOWN ALREADY AMH has been previously linked to +SR in men with iNOA undergoing mTESE prior to ART. STUDY DESIGN, SIZE, DURATION A multi-centre cross-sectional study was carried out with a cohort of 117 men with iNOA undergoing mTESE at three tertiary-referral centres. PARTICIPANTS/MATERIALS, SETTING, METHODS Data from 117 consecutive white-European men with iNOA presenting for primary couple's infertility associated with a pure male factor at three centres were analysed. Descriptive statistics was applied to compare patients with negative (−SR) versus +SR at mTESE. Multivariate logistic regression models were fitted to predict +SR at mTESE, after adjusting for possible confounders. Diagnostic accuracy of the factors associated with +SR was assessed. Decision curve analyses were used to display the clinical benefit. MAIN RESULTS AND THE ROLE OF CHANCE Overall, 60 (51.3%) men had an −SR and 57 (48.7%) had a +SR at mTESE. Patients with +SR had lower levels of baseline AMH (P  = 0.005) and higher levels of estradiol (E2) (P  = 0.01). At multivariate logistic regression analysis, lower levels of AMH (odds ratio: 0.79; 95% CI: 0.64–0.93, P  = 0.03) were associated with +SR at mTESE, after adjusting for possible confounders (e.g. age, mean testicular volume, FSH, and E2). A threshold of AMH <4 ng/ml achieved the highest accuracy for +SR at mTESE, with an AUC of 70.3% (95% CI: 59.8–80.7). Decision curve analysis displayed the net clinical benefit of using an AMH <4 ng/ml threshold. LIMITATIONS, REASONS FOR CAUTION There is a need for external validation in even larger cohorts, across different centres and ethnicities. Systematic reviews and meta-analysis to provide high level of evidence are lacking in the context of AMH and SR rates in men with iNOA. WIDER IMPLICATIONS OF THE FINDINGS Current findings suggest that slightly more than one in two men with iNOA had −SR at mTESE. Overall, men with iNOA with lower levels of AMH had a significantly higher percentage of successful SR at surgery. A threshold of <4 ng/ml for circulating AMH ensured satisfactory sensitivity, specificity, and positive predictive values in the context of +SR at mTESE. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by voluntary donations from the Urological Research Institute (URI). All authors declare no conflict of interest. TRIAL REGISTRATION NUMBER N/A [ABSTRACT FROM AUTHOR]

STUDY QUESTION What is the impact of variants in the genes INSL3 (Insulin Like 3) and RXFP2 (Relaxin Family Peptide Receptor 2), respectively, on cryptorchidism and male infertility? SUMMARY ANSWER Bi-allelic loss-of-function (LoF) variants in INSL3 and RXFP2 result in bilateral cryptorchidism and male infertility, whereas heterozygous variant carriers are phenotypically unaffected. WHAT IS KNOWN ALREADY The small heterodimeric peptide INSL3 and its G protein-coupled receptor RXFP2 play a major role in the first step of the biphasic descent of the testes, and variants in the INSL3 and RXFP2 genes have long been implicated in inherited cryptorchidism. However, only one single homozygous missense variant in RXFP2 has clearly been linked to familial bilateral cryptorchidism, so the effects of bi-allelic variants in INSL3 and heterozygous variants in both genes on cryptorchidism and male infertility remain unclear. STUDY DESIGN, SIZE, DURATION Exome data of 2412 men from the MERGE (Male Reproductive Genomics) study cohort including 1902 infertile men with crypto-/azoospermia, of whom 450 men had a history of cryptorchidism, were screened for high-impact variants in INSL3 and RXFP2. PARTICIPANTS/MATERIALS, SETTING, METHODS For patients with rare, high-impact variants in INSL3 and RXFP2 , detailed clinical data were collected and the testicular phenotype was determined. Genotyping of family members was performed to analyse the co-segregation of candidate variants with the condition. Immunohistochemical staining for INSL3 in patient testicular tissue and measuring serum INSL3 concentration was performed to analyse the functional impact of a homozygous loss-of-function variant in INSL3. For a homozygous missense variant in RXFP2 , its impact on the protein's cell surface expression and ability to respond to INSL3 in CRE reporter gene assay was determined. MAIN RESULTS AND THE ROLE OF CHANCE This study presents homozygous high-impact variants in INSL3 and RXFP2 and clearly correlates these to bilateral cryptorchidism. Functional impact of the identified INSL3 variant was demonstrated by absence of INSL3-specific staining in patients' testicular Leydig cells as well as undetectable blood serum levels. The identified missense variant in RXFP2 was demonstrated to lead to reduced RXFP2 surface expression and INSL3 mediated receptor activation. LIMITATIONS, REASONS FOR CAUTION Further investigations are needed to explore a potential direct impact of bi-allelic INSL3 and RXFP2 variants on spermatogenesis. With our data, we cannot determine whether the infertility observed in our patients is a direct consequence of the disruption of a possible function of these genes on spermatogenesis or whether it occurs secondarily due to cryptorchidism. WIDER IMPLICATIONS OF THE FINDINGS In contrast to previous assumptions, this study supports an autosomal recessive inheritance of INSL3 - and RXFP2 -related bilateral cryptorchidism while heterozygous LoF variants in either gene can at most be regarded as a risk factor for developing cryptorchidism. Our findings have diagnostic value for patients with familial/bilateral cryptorchidism and additionally shed light on the importance of INSL3 and RXFP2 in testicular descent and fertility. STUDY FUNDING/COMPETING INTEREST(S) This study was carried out within the frame of the German Research Foundation (DFG) funded by Clinical Research Unit 'Male Germ Cells: from Genes to Function' (DFG, CRU326). Research at the Florey was supported by an NHMRC grant (2001027) and the Victorian Government Operational Infrastructure Support Program. A.S.B. is funded by the DFG ('Emmy Noether Programme' project number 464240267). The authors declare no conflict of interest. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Can whole-exome sequencing (WES) reveal new genetic factors responsible for male infertility characterized by oligozoospermia? SUMMARY ANSWER We identified biallelic missense variants in the Potassium Channel Tetramerization Domain Containing 19 gene (KCTD19) and confirmed it to be a novel pathogenic gene for male infertility. WHAT IS KNOWN ALREADY KCTD19 is a key transcriptional regulator that plays an indispensable role in male fertility by regulating meiotic progression. Kctd19 gene-disrupted male mice exhibit infertility due to meiotic arrest. STUDY DESIGN, SIZE, DURATION We recruited a cohort of 536 individuals with idiopathic oligozoospermia from 2014 to 2022 and focused on five infertile males from three unrelated families. Semen analysis data and ICSI outcomes were collected. WES and homozygosity mapping were performed to identify potential pathogenic variants. The pathogenicity of the identified variants was investigated in silico and in vitro. PARTICIPANTS/MATERIALS, SETTING, METHODS Male patients diagnosed with primary infertility were recruited from the Reproductive and Genetic Hospital of CITIC-Xiangya. Genomic DNA extracted from affected individuals was used for WES and Sanger sequencing. Sperm phenotype, sperm nuclear maturity, chromosome aneuploidy, and sperm ultrastructure were assessed using hematoxylin and eosin staining and toluidine blue staining, FISH and transmission electron microscopy. The functional effects of the identified variants in HEK293T cells were investigated via western blotting and immunofluorescence. MAIN RESULTS AND THE ROLE OF CHANCE We identified three homozygous missense variants (NM_001100915, c.G628A:p.E210K, c.C893T:p.P298L, and c.G2309A:p.G770D) in KCTD19 in five infertile males from three unrelated families. Abnormal morphology of the sperm heads with immature nuclei and/or nuclear aneuploidy were frequently observed in individuals with biallelic KCTD19 variants, and ICSI was unable to rescue these deficiencies. These variants reduced the abundance of KCTD19 due to increased ubiquitination and impaired its nuclear colocalization with its functional partner, zinc finger protein 541 (ZFP541), in HEK293T cells. LIMITATIONS, REASONS FOR CAUTION The exact pathogenic mechanism remains unclear, and warrants further studies using knock-in mice that mimic the missense mutations found in individuals with biallelic KCTD19 variants. WIDER IMPLICATIONS OF THE FINDINGS Our study is the first to report a likely causal relationship between KCTD19 deficiency and male infertility, confirming the critical role of KCTD19 in human reproduction. Additionally, this study provided evidence for the poor ICSI clinical outcomes in individuals with biallelic KCTD19 variants, which may guide clinical treatment strategies. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the National Key Research and Developmental Program of China (2022YFC2702604 to Y.-Q.T.), the National Natural Science Foundation of China (81971447 and 82171608 to Y.-Q.T. 82101961 to C.T.), a key grant from the Prevention and Treatment of Birth Defects from Hunan Province (2019SK1012 to Y.-Q.T.), a Hunan Provincial Grant for Innovative Province Construction (2019SK4012), and the China Postdoctoral Science Foundation (2022M721124 to W.W.). The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

The nucleus of round spermatids, the earliest haploid male germ cells, can participate in the formation of normal zygotes when incorporated into activated oocytes. In this study, we injected mouse round spermatids into homologous mature oocytes that were kept arrested at metaphase II to induce premature chromosome condensation (PCC) of the spermatid nuclei. After full condensation of the spermatid chromosomes, the oocytes were activated by Sr2+-containing medium, into which cytochalasin B was added to prevent extrusion of the segregated female and male chromosomes as polar bodies. Out of 142 oocytes examined, 104 (73%) formed two male (pseudo)pronuclei and two female pronuclei. To restore the diploid state of these zygotes, one of the female pronuclei was removed. When cultured in vitro for 72 hours, all (n = 37) of the constructed embryos developed to the morula/blastocyst stage. When 2-cell embryos and morulae/blastocysts were transferred into pseudopregnant females, 14 (13/96) and 24% (9/37), respectively, developed into term offspring. This study indicates that the spermatid chromosomes, which had undergone PCC, moved safely to opposite poles after oocyte activation. Since round spermatids contain no (in the mouse) or little (in patients with spermatogenic failure) oocyte-activating factor, this method may be used to rescue oocytes that fail to be activated at the time of spermatid injection. [ABSTRACT FROM PUBLISHER]

A retrospective analysis in 50 couples of 53 cycles of intracytoplasmic sperm injection (ICSI) with immotile spermatozoa from testicular-retrieved spermatozoa was performed to evaluate whether total immotile spermatozoa achieved after testicular sperm extraction could fertilize ova and result in pregnancies. We assessed the efficacy of ICSI with totally immotile testicular spermatozoa extracted from the testes of azoospermic patients with severe spermatogenic failure (group 1) and compared these results with those from spermatozoa which were recovered after several hours of incubation and were motile (group 2) at the time of injection. In 19 cycles, only totally immotile spermatozoa were injected at the time of ICSI. For the remaining 34 cycles, at least one motile spermatozoon was found for injection. The oocyte fertilization rates were 51% for group 1 and 62% for group 2 (P < 0.02). Eighteen of 19 cycles in group 1 (90%) and all 34 (100%) cycles in group 2 had embryos for replacement. The mean number of embryos per cycle was 5.2 ± 0.8 and 7.5 ± 0.9 in groups 1 and 2 respectively; this and the embryo quality (cumulative embryo scoring = 40 ± 8 for group 1 and 50 ± 7 for group 2), and clinical pregnancy rates (15.8% per oocyte retrieval in group 1 and 23.5% in group 2) were not significantly different between groups. Fertilization, cleavage and pregnancy can be achieved with intracytoplasmic testicular sperm injection from patients with immotile spermatozoa, at levels comparable with those of ICSI using motile spermatozoa. [ABSTRACT FROM PUBLISHER]

The aim was to determine whether proton magnetic resonance spectroscopy (1H-MRS) of metabolites such as glycerophosphorylcholine (GPC), choline, citrate and lactate in human seminal plasma can be used to differentiate (i) different azoospermic patients and (ii) different forms of spermatogenic failure including those who had undergone radiation therapy or chemotherapy. Semen samples were provided by men with obstructive azoospermia and spermatogenic failure who had serum follicle stimulating hormone (FSH) values within the normal range and either more or less than normal. Four prominent constituents of seminal plasma were identified by 1H-MRS: GPC, choline, citrate and lactate. The peak area ratios of choline/citrate as well as choline/lactate were significantly different (P < 0.01) between groups with spermatogenic failure and obstructive azoospermia. When the serum FSH values were normal in men with spermatogenic failure and obstructive azoospermia, a significant difference was found in the GPC/choline ratio (P < 0.001). When the FSH values were normal, the GPC/choline ratio appeared to be a very important parameter able to differentiate not only between cases of spermatogenic failure and obstructive azoospermia but also between different forms of spermatogenic failure. These results demonstrate the potential use of 1H-MRS on human seminal plasma in a new approach in the management of male infertility. [ABSTRACT FROM AUTHOR]