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Abstract Background Male infertility due to spermatogenesis defects affects millions of men worldwide. However, the genetic etiology of the vast majority remains unclear. The present study was undertaken to assess the association of DNAH6 and ATPase6 genes in asthenozoospermia patients in the northern region of India. Methods A total of 60 semen samples were collected for the study, of which 30 were from the case group and 30 were from the control group. The semen samples for the case group (asthenozoospermia) and control groups were collected from IVF and Reproductive Biology Centre, Maulana Azad Medical College, New Delhi. Sperm count and motility were classified as per World Health Organization (WHO 2021) protocol. A total genomic DNA was extracted as per the stranded TRIZOL method with little modification. Results In-vitro molecular characterizations of DNAH6 and ATPase6 genes in both groups were checked by Polymerase Chain Reaction (PCR). The 675 bp and 375 bp amplicons were amplified using PCR for ATPase6 and DNAH6 genes. Our study results showed a significant (P ≤ 0.05) null deletion of DNAH6 and ATPase6 genes in asthenozoospermia patients as compared to the control. We found the significant null deletion of DNAH6 in case 45.0%, and the control group was 11.7%. However, in the case of APTase6, it was 26.7% and 10.0%, respectively. Conclusions Our study concluded that the presence of DHAH6 and ATPase6 genes had a significant impact on male infertility.

Background: Male infertility due to spermatogenesis defects affects millions of men worldwide. However, the genetic etiology of the vast majority remains unclear. The present study was undertaken to assess the association of DNAH6 and ATPase6 genes in asthenozoospermia patients in the northern region of India. Methods: A total of 60 semen samples were collected for the study, of which 30 were from the case group and 30 were from the control group. The semen samples for the case group (asthenozoospermia) and control groups were collected from IVF and Reproductive Biology Centre, Maulana Azad Medical College, New Delhi. Sperm count and motility were classified as per World Health Organization (WHO 2021) protocol. A total genomic DNA was extracted as per the stranded TRIZOL method with little modification. Results: In-vitro molecular characterizations of DNAH6 and ATPase6 genes in both groups were checked by Polymerase Chain Reaction (PCR). The 675 bp and 375 bp amplicons were amplified using PCR for ATPase6 and DNAH6 genes. Our study results showed a significant (P ≤ 0.05) null deletion of DNAH6 and ATPase6 genes in asthenozoospermia patients as compared to the control. We found the significant null deletion of DNAH6 in case 45.0%, and the control group was 11.7%. However, in the case of APTase6, it was 26.7% and 10.0%, respectively. Conclusions: Our study concluded that the presence of DHAH6 and ATPase6 genes had a significant impact on male infertility. [ABSTRACT FROM AUTHOR]

Introduction: Familial adenomatous polyposis (FAP) is a rare and hereditary disease in which multiple precancerous polyps develop in the patient's colon. Familial adenomatous polyposis is caused by mutations in the APC gene (5q21). According to new research, in addition to nuclear disorders, mitochondrial functional disorders are also one of the essential carcinogenic factors and also a promising target for cancer treatment. The aim of this study was to investigate the nucleotide changes of mitochondrial ATPase6 and MT-CYB genes in patients with FAP. Methods: In this study, 9 Iranian families with Familial adenomatous polyposis were investigated to study mutations in mitochondrial genes. For this purpose, a fragment with the length of 558bp containing the ATPase6 gene and also a fragment containing the MT-CYB gene with a length of 853bp were studied using the Touchdown-PCR method and sequencing. Sequencing results were analyzed with several bioinformatics software and databases, including ExPASy, SIFT, PSIPRED, PolyPhen-2, I-Mutant, PROVEAN, PredictSNP, and PyMol. Results: In this research, five mutations were observed in the mitochondrial ATPase6 gene. Three mutations were synonymous (c.A8901G; p.L125L, c.C8958T; p.I144I and c.C8943T; p.P139P) and two non-synonymous mutations (c.T8780C; p.L85P and c.G9133A; p.E203K). Furthermore, two synonymous mutations (c.A15607G; p.K287K and c.C15833T; p.L363L) and one non-synonymous mutation (c.C15452A; p.L236I) were observed in the MT-CYB gene. Conclusion: In this study, ATPase6 and MT-CYB genes were investigated in the patients with Familial adenomatous polyposis, and 5 and 3 mutations and nucleotide changes were observed in affected patients, respectively. Considering that mitochondrial genome mutations can play a role in tumorigenesis, identifying new mutations can be effective in early cancer diagnosis. More studies are needed to confirm the association between mitochondrial mutations and FAP disease.

RESUMO Objetivo: A síndrome de Leigh é uma doença neurodegenerativa com incidência de 1:40.000 nados-vivos. Apresenta ampla heterogeneidade clínica, bioquímica e genética, mas com alterações neuropatorradiológicas homogêneas. Não existe tratamento específico, e o prognóstico é reservado. O objetivo deste estudo foi familiarizar os profissionais de saúde com a doença. Descrição do caso: Menina de 16 meses, com hipotonia axial e atraso do desenvolvimento psicomotor. Dos exames realizados: cariótipo, potenciais auditivos evocados e avaliação oftalmológica normais; presença de hiperlactacidemia e hipocitrulinemia. Após a realização de ressonância magnética cerebral sob anestesia, observou-se agravamento da hipotonia com necessidade de internação por episódios de cianose/apneia. O eletroencefalograma não mostrou atividade epileptiforme. A neuroimagem revelou hipersinal lenticular bilateral com lesão do putâmen e do globo pálido esquerdo. Encontrou-se a mutação 8993T>G (MT-ATP6) no DNA mitocondrial. Comentários: De 10 a 30% dos doentes com síndrome de Leigh apresentam mutações do DNA mitocondrial. A descompensação com agravamento neurológico após intervenção anestésica está descrita e, nesse caso, apoiou o diagnóstico. Importante alertar para casos semelhantes, com diminuição de exames invasivos para diagnóstico.

Objective: Leigh syndrome is a neurodegenerative disorder with an incidence of 1:40,000 live births. It presents wide clinical, biochemical, and genetic heterogeneity, but with homogenous neuropatoradiological alterations. There is no specific treatment, and the prognosis is reserved. This case report aimed familiarize health professionals with the disease. Case Description: A 16-month-hold girl who was followed in outpatient clinic due to axial hypotonia and delayed psychomotor development. Karyotype, auditory evoked potentials and ophthalmologic evaluation were normal. Evidence of hyperlactacidemia and hypocitrullinemia was detected in the patient. After performing brain magnetic resonance under anesthesia, hypotonia got worse, and the patient was hospitalized after an episode of cyanosis and apnea. The electroencephalogram showed no epileptiform activity. Neuroimaging revealed bilateral lenticular hyperintensity, especially in the putamen and in the left globus pallidus regions. Molecular analysis revealed an 8993T>G (MT-ATP6) mutation in the mitochondrial DNA. Comments: Between 10 and 30% of individuals with Leigh syndrome have mitochondrial DNA mutations. The decompensation after anesthetic intercurrences is typically associated with neurological deterioration and, in this case, increased the diagnosis suspicion. It is important to alert for similar cases and to reduce invasive diagnostic tests if the diagnosis is suspected. [ABSTRACT FROM AUTHOR]

La maduración del ovocito en los folículos preovulatorios comprende complejos eventos regulados en parte por gonadotropinas. Sin embargo, para entender estos eventos, es necesario identificar los diferentes genes que participan en la maduración. Uno de estos genes corresponde a la proteína ATPasa6, componente de la ATP sintasa que se sobreexpresa durante la maduración de los ovocitos, pero hasta ahora, no ha sido comprobada su participación experimentalmente. Por lo tanto, el objetivo del presente estudio se encaminó a determinar si la ATPasa6 tiene un papel relevante en la maduración de los ovocitos del cerdo, a partir de la conformación de dos grupos de ovocitos: El experimental microinyectados con un RNA interferente para ATPasa6, silenciando su expresión, y el grupo control microinyectados con un RNAi para un gen de invertebrado. Después de la microinyección, ambos grupos se cultivaron in vitro durante 48 h en medio de maduración. El grupo microinyectado con siRNA para ATPasa6 mostró una disminución del 71% en la expresión de este gen a las 24 h de incubación, en tanto que el porcentaje de ovocitos maduros en este grupo disminuyó 51.1% (67.5% en el grupo control vs 33% en el grupo tratado con ATPasa6-RNAi; p<0.05 con t de Student). Estos resultados permiten concluir que la ATPasa6 juega un papel importante durante la maduración de los ovocitos del cerdo. [ABSTRACT FROM AUTHOR]

Objective: Schizophrenia is a serious mental disorder. Mutations in mitochondrial genes can change energy metabolism. Telomere is a tandem sequence at the end of chromosomes. Shorter telomere length has been shown in schizophrenia. The aim of this study was to determine the relationship between ATPase6 gene mutations and telomere length in schizophrenia patients., Methods: Blood samples of 34 patients and 34 healthy controls were used. In this study conventional PCR, Sanger sequencing technic and real-time PCR were utilized., Results: Five different mutations (A8860G, A8836, G8697A, C8676T, and A8701G) in the ATPase6 gene were identified in schizophrenia patients. The most seen mutation was A8860G (94%). Telomere length analysis indicated the relation of ATPase6 gene mutations and telomere length variations ( p = 0.001). Patients carrying the A8860G mutation had shorter telomere lengths than patients carrying other mutations. Comparing telomere length between schizophrenia patients and healthy controls revealed that the mean telomere length of schizophrenia patients was shorter than healthy controls ( p = 0.006). The demographic analysis demonstrated a significant relationship between marital status and telomere length ( p = 0.011). Besides that, the duration of the illness is another factor that impacts telomere length ( p = 0.044). There is no significant relation between telomere length and other clinical and demographic characteristics including education status, age, gender, etc., Conclusion: In conclusion, telomere length and ATPase6 gene mutations have a significant relation. Studies with larger patient populations and investigation of other mitochondrial gene mutations will make the clearer link between telomere length and mitochondrial mutations.

Background Breast cancer is the most common malignancy in women throughout the world. Mitochondria play important roles in cellular energy production, free radical generation and apoptosis. Identification of mitochondrial DNA mutations and/or polymorphisms as cancer biomarkers is rapidly developing in molecular oncology research. Methods In this study, the DNA alterations of the mitochondrial ATPase 6 and 8 genes were investigated in 49 breast cancer patients using PCR amplification and direct DNA sequencing on mtDNA. A possible association between these variants and tumorigenesis was assessed. Furthermore, the impact of non-synonymous substitutions on the amino acid sequence was evaluated using the PolyPhen-2 software. Results Twenty eight distinct somatic mitochondrial DNA variants were detected in tumor tissues but not in the corresponding adjacent non-tumor tissues. Among these variants, 9 were observed for the first time in breast cancer patients. The mtDNA variants of A8384 (T7A), T8567C (I14T), G8572A (G16S), A9041G (H172R) and G9055A (A177T) showed the most significant effects probably due to damaging changes to the resulting protein. Furthermore, non-synonymous amino acid changing variants were more frequent in the ATPase6 gene compared to the ATPase8 gene. Conclusion Our results showed that the ATPase6 gene is more susceptible to variations in breast cancer and may play an important role in tumorigenesis by changing the energy metabolism level in cancer cells. [ABSTRACT FROM AUTHOR]

We previously performed cDNA subtraction between the mouse mandibles on embryonic day 10.5 (E10.5) in the pre-initiation stage of the odontogenesis and E12.0 in the late initiation stage to identify genes expressed at its beginning. Adenosine triphosphate synthase subunit a ( Atpase6) is one of the highly expressed genes in the E12.0 mandible including tooth germs. In situ hybridization was conducted using the mouse mandibular first molar from E10.5 to E18.0 to determine the precise expression patterns of Atpase6 mRNA in the developing tooth germ. Atpase6 mRNA was strongly expressed in the presumptive dental epithelium and the underlying mesenchyme at E10.5, and in the thickened dental epithelium at E12.0 and E13.0. Strong in situ signals were observed in the epithelium at E14.0, and in the enamel organ excluded the area of the primary enamel knot at E15.0. Atpase6 was strongly expressed in the inner enamel epithelium, the adjacent stratum intermedium, and the outer enamel epithelium in the cervical loops from E16.0 to E18.0. In addition, strong Atpase6 signals were coincidently demonstrated in various developing cranio-facial organs. These results suggest that Atpase6 participates in the high energy-utilizing functions of the cells related to the initiation and the development of the tooth germ as well as those of the other cranio-facial organs. [ABSTRACT FROM AUTHOR]

Purpose: Primary ovarian insufficiency (POI) is a heterogeneous, multifactorial disorder. Though genetic anomalies, infections, autoimmune disorder and hormonal imbalance are few of the causes of POI, in the majority of patients (50-60%) no etiology has been identified. Mitochondrial bioenergetics and biogenesis play an important role in oocyte and embryo development, whereas mtDNA integrity and content are essential for the normal development of oocytes. ATPase6 helps to maintain the mt genome integrity, and mutations in ATPase6 are associated with overproduction of reactive oxygen species (ROS) in a variety of diseases; however, its role in POI has not been evaluated. Therefore, we planned to evaluate the potential role of ATPase6 gene mutations and associated oxidative stress in idiopathic cases of POI.Methods: This pilot study included: 20 cases of POI with FSH level of >40 mIU/ml; 4 cases of occult ovarian insufficiency (occult OI) with irregular menses and mean FSH levels of 16.4 mIU/ml; and 20 age-matched healthy female controls (FSH 2-5 mIU/ml). ROS levels in blood plasma were measured by luminol-dependent chemiluminescence assay and the ROS values were expressed as relative light unit per minute (RLU/min). mtDNA ATPase6 gene was amplified and sequenced from the blood lymphocyte DNA.Results: Of all, 50% patients showed nucleotide changes in the ATPase6 gene, as compared to 10% in controls, and the majority of these mutations were non-synonymous. ATPase6 mt.8684 C>T and mt.9094 C>T were found to be significantly (P < 0.005) higher in cases as compared to controls. ROS levels were found to be significantly (P < 0.005) higher in POI and occult OI patients compared to controls and nucleotide changes were found to positively correlate with ROS levels. Moreover, ROS production was found to positively correlate (r = 0.7038, P < 0.001) with FSH levels of the patients (POI and OI) compared to controls.Conclusions: This pilot study clearly demonstrates for the first time ATPase6 gene nucleotide alterations and elevated ROS levels in idiopathic cases of POI. Therefore, it may be possible that OS associated with ATPase6 gene mutation may be causal in idiopathic cases of premature OI. However, larger studies with inclusion of more cases of both POI and occult OI are required to strongly establish the correlation between oxidative stress and mitochondrial nucleotide alterations in the pathogenesis of POI. Such cases with OS-induced POI may benefit immensely by early diagnosis and prompt antioxidant administration. [ABSTRACT FROM AUTHOR]

Abstract: Laniarius is one of the larger genera within the avian bush-shrike radiation, the family Malaconotidae. Fairly homogenous by size and shape but highly variable by colours, these have been classified mainly on basis of plumage colours. In the present study, which is the first taxon-dense analysis of the genus Laniarius based on molecular sequence data (nuclear BRM15 intron-15, and mitochondrial ND2 and ATPase6 genes), we investigate interrelationships between 16 species and 34 subspecies of Laniarius. Altogether 2094bp were aligned and subjected to maximum likelihood and Bayesian inference analyses. Results strongly support the monophyly of Laniarius, and place it close to Chlorophoneus, but without outlining a precise sister-group. In a generally well-resolved phylogeny of Laniarius, L. leucorhynchus and L. atrococcineus constitute deep branches and the remaining species form five clades which are not concordant with previously defined superspecies. The black and white boubous belong to two different clades. L. aethiopicus appears polyphyletic and our results support the resurrection of Laniarius major, Laniarius erlangeri and Laniarius sublacteus. We also find that L. liberatus, described in 1991 based on the only known live individual, is identified as an unusual colour morph from L. erlangeri. The black boubous are not monophyletic; L. funebris and L. leucorhynchus appear as isolated species whereas L. poensis and L. fuelleborni are sister-taxa. We recovered the polyphyly of crimson boubous and new hypotheses on their relationships have been generated. Overall, the variation in pigments and patterns does not follow phylogenetic lineages. The plumage coloration could be thoroughly subject to modification and it could not reflect exactly colour plumages of the parents. From then on, the plumage coloration appears as an unreliable morphological character for defining species and species groups. [Copyright &y& Elsevier]

Abstract: We infer the phylogenetic relationships of finescale shiners of the genus Lythrurus, a group of 11 species of freshwater minnows widely distributed in eastern North America, using DNA sequences from the ND2 (1047bp), ATPase8 and 6 (823bp), and ND3 (421bp) mitochondrial protein-coding genes. The topologies resulting from maximum parsimony, Bayesian, and maximum likelihood tree building methods are broadly congruent, with two distinct clades within the genus: the L. umbratilis clade (L. umbratilis + L. lirus + (L. fasciolaris + (L. ardens, L. matutinus))) and the L. bellus clade (L. fumeus + L. snelsoni + (L. roseipinnis + (L. atrapiculus + (L. bellus, L. algenotus)))). Support is weak at the base of several clades, but strongly supported nodes differ significantly from prior investigations. In particular, our results confirm and extend earlier studies recovering two clades within Lythrurus corresponding to groups with largely “northern” and “southern” geographic distributions. Several species in this genus are listed in the United States as threatened or of special concern due to habitat degradation or limited geographic ranges. In this study, populations assigned to L. roseipinnis show significant genetic divergence suggesting that there is greater genetic diversity within this species than its current taxonomy reflects. A full accounting of the biodiversity of the genus awaits further study. [Copyright &y& Elsevier]

Abstract: We present first insights into the molecular phylogeny of the grayling genus Thymallus (Salmonidae) using sequences from the mitochondrial control region and ATPase6 genes. A suite of analytical approaches were applied for each gene separately and for the combined data. The ATPase6 gene is shown to have a mean divergence rate across the genus of 2.46 times faster than the complete control region. Based on the combined data, four major (internal) clades, presumably originating in the Pliocene, were resolved with high support in all analyses and represented two distinct lineages in the Amur basin, one lineage in all remaining Siberian and Mongolian drainages, and one lineage corresponding to European grayling Thymallus thymallus. The resolution of multiple lineages, from both additional internal and terminal clades, within each major drainage basin underscores the complexity and effects that Pleistocene hydrological dynamics have had on the distribution of biodiversity in Siberia. [Copyright &y& Elsevier]

We used mitochondrial/nuclear gene sequence analyses to determine the historical relationships of the endemic species of Todus (Aves: Todidae) from the Caribbean. We collected 1920-bp of nucleotide sequence data from the mitochondrial genes cytochrome b, ATPase 6, ATPase 8, and 591-bp of the single-copy nuclear gene c-mos for all Todus species and representatives of their outgroup taxa (Hylomanes, Barypthengus, Chloroceryle, Ceryle, and Galbula) to reconstruct the evolutionary history (via parsimony and maximum likelihood) of the five Todus species. The substitution rates among the mitochondrial genes were found to be much higher than the substitution rate for the c-mos gene, consequently resulting in higher substitutional saturation for the mitochondrial genes. When we applied weighting schemes to account for the variance in substitutional heterogeneity among the genes then parsimony and likelihood analyses both demonstrate that the genus Todus is monophyletic and closer to the Hylomanes and Barypthengus genera than the Chloroceryle and Ceryle genera. The mitochondrial-gene trees and nuclear-gene trees both show similar results, thus providing support for the relationships among the taxa from loci within two independently evolving genomes. The nuclear gene c-mos was found, therefore, to be a viable nuclear gene candidate for resolving intermediate and deep divergences. [Copyright &y& Elsevier]

The key role of mitochondria in the apoptotic process is well understood, but not many data are available regarding the specific role of mitochondrial DNA mutations in determining cell fate. We investigated whether two mitochondrial DNA mutations (L217R and L156R) associated with maternally-inherited Leigh syndrome may play a specific role in triggering the apoptotic cascade. Considering that different nuclear genetic factors may influence the expression of mtDNA mutations, we used a 143BTK– osteosarcoma cell line deprived from its own mtDNA in order to insert mutated mtDNAs. Analysis of mitochondrial features in these cybrids indicated that both mitochondrial DNA mutations produced evidence of biochemical, functional and ultrastructural modifications of mitochondria, and that these modifications were associated with an increased apoptotic proneness. Cybrids were highly susceptible to two different apoptotic stimuli, tumour necrosis factor-α and Staurosporin. The mechanism involved was the mitochondrial ‘intrinsic’ pathway, i.e. the caspase 9-driven cascade. More importantly, our results also indicated that the polarization state of the mitochondrial membrane, i.e. a constitutive hyperpolarization detected in cybrid clones, played a specific role. Interestingly, the different effects of the two mutations in terms of susceptibility to apoptosis probably reflect the deeper bioenergetic defect associated with the L217R mutation. This work provides the first evidence that hyperpolarization of mitochondria may be a ‘risk factor’ for cells with a deep ATPase dysfunction, such as cells from patients with maternally-inherited Leigh syndrome. [ABSTRACT FROM AUTHOR]

This study reports the first clearly defined heteroplasmic mutation in immature human sperm cells. The human sperm mitochondrial genome from residue 8186–9341 was analysed with the aim of identifying point mutations which may be associated with human male infertility. The semen samples analysed were obtained from 88 fertile men, 19 with oligozoospermia, and 12 with severe oligozoospermia. Using single strand conformation polymorphism analysis a heteroplasmic T to C transition was detected in the ATPase6 gene, at nucleotide position 8821, in semen samples from one out of 12 (8%) severely oligozoospermic men, but not in oligozoospermic men or normospermic men. This mutation changed the amino acid serine to proline at residue 99 of the mitochondrial ATPase6 in a region which is highly conserved in other vertebrates including rat, bovine, chicken, salmonids and Xenopus. The mutation was detected in semen samples collected from the same man 9 months apart and in peripheral blood lymphocytes. Single sperm cell analyses did not find this mutation in the mature sperm, but the mutation was detected in 7% of immature spermatids. Our finding suggests that immature spermatids with this mutation fail to develop fully. [ABSTRACT FROM AUTHOR]

We evaluated a patient, born after a normal 38-week pregnancy, with psychomotor retardation, poor coordination of ocular movements, recurrent vomiting and severe lactic acidosis. The patient was admitted to hospital at 2 months of age because of a mitochondrial-like syndrome and died at the age of 4.5 months. Array-comparative genomic hybridization (a-CGH) analysis revealed a homozygous deletion in 5q11.2 involving NADH dehydrogenase (ubiquinone) Fe-S protein 4, 18 kDa (NADH-coenzyme Q reductase; NDUFS4). Both parents were heterozygous for the mutation. The array revealed a deletion of ~32kb that includes exon 2 of NDUFS4 subsequently confirmed by real time-PCR and multiplex PCR. NDUFS4 was previously correlated to Leigh syndrome since mutations in this gene block the assembly of complex I. This result demonstrates the relevance of a-CGH screening in patients affected by metabolic disorders of unknown etiology., (Copyright © 2013 Elsevier B.V. All rights reserved.)