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Azoospermia, a severe form of male infertility characterized by the complete absence of sperm in the ejaculate, affects about 1% of the male population, with most cases attributed to nonobstructive azoospermia (NOA) caused by gametogenic failure. NOA has various genetic origins, including chromosomal abnormalities, Y chromosome microdeletions, and monogenic mutations. Although whole-exome sequencing (WES) has identified over thirty candidate genes associated with NOA, the genetic causes of most cases have yet to be elucidated. In our study, we selected seven consanguineous families diagnosed with azoospermia from a total of 21 male infertile families recruited from the rural area of Pakistan. Blood samples were collected from both patients and fertile controls for DNA extraction, followed by WES to identify potential causative recessive monogenic variants linked to male infertility. We successfully identified five deleterious variants among five of the seven families, including three missense biallelic substitutions in WWC2, RPL10L, and SOHLH1, a hemizygous deletion in ESX1, and a homozygous deletion in TXNDC2, which have potentially pathogenic relevance to the azoospermia of human male infertility. These novel findings enhance our understanding of the molecular mechanisms underlying the complex etiology of azoospermia, offering valuable insights for genetic counseling and diagnostics and paving the way for future therapeutic approaches. [ABSTRACT FROM AUTHOR]

In mammals, the production of mature oocytes necessitates rigorous regulation of the discontinuous meiotic cell-cycle progression at both the transcriptional and post-transcriptional levels. However, the factors underlying this sophisticated but explicit process remain largely unclear. Here we characterize the function of N-acetyltransferase 10 (Nat10), a writer for N4-acetylcytidine (ac4C) on RNA molecules, in mouse oocyte development. We provide genetic evidence that Nat10 is essential for oocyte meiotic prophase I progression, oocyte growth and maturation by sculpting the maternal transcriptome through timely degradation of poly(A) tail mRNAs. This is achieved through the ac4C deposition on the key CCR4-NOT complex transcripts. Importantly, we devise a method for examining the poly(A) tail length (PAT), termed Hairpin Adaptor-poly(A) tail length (HA-PAT), which outperforms conventional methods in terms of cost, sensitivity, and efficiency. In summary, these findings provide genetic evidence that unveils the indispensable role of maternal Nat10 in oocyte development. Generation of mature oocytes requires tight regulation of a discontinuous meiotic cell cycle. Here they show that the acetyltransferase Nat10 mediates modification of RNAs targeted for degradation and find that this process is essential for female oocyte meiosis and maturation. [ABSTRACT FROM AUTHOR]

The segregation and maintenance of a dedicated germline in multicellular organisms is essential for species propagation in the sexually reproducing metazoan kingdom. The germline is distinct from somatic cells in that it is ultimately dedicated to acquiring the “totipotency” and to regenerating the offspring after fertilization. The most striking feature of germ cells lies in the presence of characteristic membraneless germ granules that have recently proven to behave like liquid droplets resulting from liquid–liquid phase separation (LLPS). Vasa/Ddx4, a faithful DEAD-box family germline marker highly conserved across metazoan species, harbors canonical DEAD-box motifs and typical intrinsically disordered sequences at both the N-terminus and C-terminus. This feature enables it to serve as a primary driving force behind germ granule formation and helicase-mediated RNA metabolism (e.g., piRNA biogenesis). Genetic ablation of Vasa/Ddx4 or the catalytic-dead mutations abolishing its helicase activity led to sexually dimorphic germline defects resulting in either male or female sterility among diverse species. While recent efforts have discovered pivotal functions of Vasa/Ddx4 in somatic cells, especially in multipotent stem cells, we herein summarize the helicase-dependent and -independent functions of Vasa/Ddx4 in the germline, and discuss recent findings of Vasa/Ddx4-mediated phase separation, germ granule formation and piRNA-dependent retrotransposon control essential for germline development. [ABSTRACT FROM AUTHOR]

Coccidiosis is recognized as one of the most widespread and pathogenic parasitic infections in migratory waterfowl throughout the world. It can be caused by several species of Eimeria. We sequenced the complete mitochondrial genome (mtDNA) of Eimeria anseris from wintering greater white-fronted geese (Anser albifrons) in China. The complete E. anseris mtDNA is 6179 bp in size and contains three protein-coding genes (CYT B, COI, and COIII), 12 gene fragments for large subunit ribosomal RNA (rRNA), and seven gene fragments for small subunit rRNA, but no transfer RNA genes. Available complete Eimeria mtDNA sequences are highly conserved in sequence: the sequences are all similar in length; with the same three protein-coding genes and fragmented rRNA genes; ATG is generally the start codon, and TAA and TAG are the most frequently used stop codons. Our molecular phylogenetic analyses show some species clustering into host-specific clades, but many species do not follow clear coevolutionary host segregating patterns. The results suggest that Eimeria spp. from turkeys and chickens are paraphyletic groups, while Eimeria species isolated from rabbits are a monophyletic group. E. anseris, which infects A. albifrons, and another group of Eimeria isolated from chickens form a closely related monophyletic clade. [ABSTRACT FROM AUTHOR]

The complete mitogenome of Acheta domesticu is 16,423 bp in length, contains the typical set of 37 genes, including 13 protein-coding genes (PCGs) (ATP6, ATP8, COI-III, ND1-6, ND4L, and Cyt b), two rRNAs (12S rRNA and 16S rRNA), 22 tRNAs, and a putative CR (D-loop). All PCGs start with an ATG codon except ATP8, ND3, and ND5 start with ATT and ND6 start with ATC. TAA is the most frequent stop codon although COIII end with the single nucleotide T-. The new mtDNA sequence contains 12S rRNA and 16 rRNA of rRNAs, which are located between tRNALeu and D-loop, separated by tRNAVal. The phylogenetic tree support A. domesticu has close relative with Loxoblemmus equestris. [ABSTRACT FROM AUTHOR]

The complete mitogenome of Gryllus bimaculatus is 16,301 bp in length, contains the typical set of 37 genes, including 13 protein-coding genes (PCGs) (ATP6, ATP8, COI-III, ND1-6, ND4L, and Cyt b), two rRNAs (12S rRNA and 16S rRNA), 22 tRNAs, and a putative CR (D-loop). ATT, ATG, and ATA are the most start codon. TAA is the most frequent stop codon. The new mtDNA sequence contains 16S rRNA and 12S rRNA of rRNA, which is located between tRNALeu and D-loop, separated by tRNAVal. All tRNA genes possess the typical clover leaf secondary structure except for tRNASer(AGN) and tRNALeu(CUN), which lacks a dihydroxyuridine (DHU) arm. The D-loop (1585 bp) located the end of mitochondrial genome sequences. The phylogenetic trees support Chiromantes haematochir has close relative with Velarifictorus hemelytrus and Teleogryllus emma. [ABSTRACT FROM AUTHOR]

The complete mitogenome of Chiromantes haematocheir is 15 899 bp in length contains the typical set of 37 genes, including 13 protein-coding genes (PCGs) (ATP6, ATP8, COI-III, ND1-6, ND4L, and Cyt b), two rRNAs (12S rRNA and 16S rRNA), 22 tRNAs, and a putative CR (D-loop). All PCGs start with an ATG codon except ND1 start with ATT and ND3 start with ATA. TAA is the most frequent stop codon, although COI end with TA-, and COII stop with the single nucleotide T-. The new mtDNA sequence contains 12S rRNA and 16S rRNA of rRNAs, separated with tRNAval. All tRNAs possess the typical clover leaf secondary structure except for tRNASer(AGN) and tRNALeu(CUN), which lacks a dihydroxyuridine (DHU) arm. The CR is 826 bp in length, located between 12S rRNA and tRNAGlx. The phylogenetic trees support Chiromantes haematochir has close relative with Sesarmops sinensis and Sesarmane glectum. [ABSTRACT FROM AUTHOR]