Asthenozoospermia is a common cause of male infertility, but its etiology remains incompletely understood. We recruited three Pakistani infertile brothers, born to first-cousin parents, displaying idiopathic asthenozoospermia but no ciliary-related symptoms. Whole-exome sequencing identified a missense variant (c.G5408A, p.C1803Y) in DNAH17, a functionally uncharacterized gene, recessively cosegregating with asthenozoospermia in the family. DNAH17, specifically expressed in testes, was localized to sperm flagella, and the mutation did not alter its localization. However, spermatozoa of all three patients showed higher frequencies of microtubule doublet(s) 4–7 missing at principal piece and end piece than in controls. Mice carrying a homozygous mutation (Dnah17^M/M) equivalent to that in patients recapitulated the defects in patients’ sperm tails. Further examinations revealed that the doublets 4–7 were destabilized largely due to the storage of sperm in epididymis. Altogether, we first report that a homozygous DNAH17 missense variant specifically induces doublets 4–7 destabilization and consequently causes asthenozoospermia, providing a novel marker for genetic counseling and diagnosis of male infertility.

Multiple morphological abnormalities of the sperm flagella (MMAF) are the most severe form of asthenozoospermia due to impaired axoneme structure in sperm flagella. Dynein arms are necessary components of the sperm flagellar axoneme. In this study, we recruited 3 unrelated consanguineous Pakistani families with multiple MMAF-affected individuals, who had no overt ciliary symptoms. Whole-exome sequencing and Sanger sequencing identified 2 cilia and flagella associated protein 57 ( CFAP57 ) loss-of-function mutations (c.2872C>T, p. R958*; and c.2737C>T, p. R913*) recessively segregating with male infertility. A mouse model mimicking the mutation (c.2872C>T) was generated and recapitulated the typical MMAF phenotype of CFAP57 -mutated individuals. Both CFAP57 mutations caused loss of the long transcript-encoded CFAP57 protein in spermatozoa from MMAF-affected individuals or from the Cfap57 -mutant mouse model while the short transcript was not affected. Subsequent examinations of the spermatozoa from Cfap57 -mutant mice revealed that CFAP57 deficiency disrupted the inner dynein arm (IDA) assembly in sperm flagella and that single-headed IDAs were more likely to be affected. Thus, our study identified 2 pathogenic mutations in CFAP57 in MMAF-affected individuals and reported a conserved and pivotal role for the long transcript-encoded CFAP57 in IDAs’ assembly and male fertility.

RAD51AP2 is required specifically for efficient meiotic recombination to form crossover between X and Y chromosomes.

With the advances of next-generation sequencing technology, the field of disease research has been revolutionized. However, pinpointing the disease-causing variants from millions of revealed variants is still a tough task. Here, we have reviewed the existing linkage analysis tools and presented PedMiner, a web-based application designed to narrow down candidate variants from family based whole-exome sequencing (WES) data through linkage analysis. PedMiner integrates linkage analysis, variant annotation and prioritization in one automated pipeline. It provides graphical visualization of the linked regions along with comprehensive annotation of variants and genes within these linked regions. This efficient and comprehensive application will be helpful for the scientific community working on Mendelian inherited disorders using family based WES data.

The testis supports spermatogenesis through a tightly regulated microenvironment, and the bacterial microbiome (BM) may influence host cells through immune and metabolic pathways, thereby impacting reproductive capacity. Here, we applied invasion-adhesion-directed expression sequencing (INVADE-seq), a single-cell RNA sequencing approach that simultaneously captures host and bacterial transcripts, to examine how bacterial signals shape testicular cell states. We detected a sparse but widespread bacterial presence across multiple cell types, with somatic and early germ cells outside the blood-testis barrier (BTB) showing relatively higher bacterial abundance. Bacterial load increased with age, coinciding with transcriptional signatures of reduced BTB function. At the cellular level, bacterial-positive Leydig cells exhibited activation of steroidogenic genes, whereas macrophages upregulated pathways related to autophagy and immune modulation. These findings not only deepen our understanding of testicular microbiome biology but also hold promise for the discovery of novel diagnostic biomarkers and therapeutic targets for BM-related and age-associated male subfertility.

Background: Oligoasthenoteratozoospermia (OAT), characterized by reduced sperm count, impaired motility, and abnormal morphology, is a major cause of male infertility with substantial genetic heterogeneity. However, the underlying genetic etiology remains unresolved in a large proportion of affected individuals. Objectives: This study aimed to identify novel genetic causes of human OAT and to investigate the molecular and clinical consequences of the identified variants. Materials and Methods: Whole‐exome sequencing was performed in infertile men diagnosed with severe OAT. Identified variants were evaluated by population database screening and functional analyses, including quantitative mRNA assessment, label‐free proteomics, immunofluorescence staining, and transmission electron microscopy (TEM). Clinical outcomes following assisted reproductive treatment were also documented. Results: We identified CCDC189 as a novel pathogenic gene associated with human OAT. Two unrelated infertile men carried homozygous variants in CCDC189 , including a frameshift variant (c.709_711del, p.W237Afs*3) and a missense variant (c.898C>T, p.R300W), both of which were rare in population databases. Clinically, both individuals exhibited severe OAT with profound acrosomal abnormalities and multiple morphological defects of the sperm flagella. TEM analysis revealed acrosomal detachment, cytoplasmic retention, loss of radial spokes, and absence of the central pair complex, indicating severe disruption of axonemal architecture. Consistently, CCDC189 mRNA levels were markedly reduced, and proteomic and immunofluorescence analyses confirmed the loss of CCDC189 protein along with its interacting partner CABCOCO1. Despite severe structural abnormalities, intracytoplasmic sperm injection (ICSI) using ejaculated sperm from one patient resulted in normal fertilization, high‐quality embryo development, and an ongoing clinical pregnancy. Conclusion: Our findings establish CCDC189 as a pathogenic gene underlying human OAT and expand the spectrum of coiled‐coil domain–containing proteins essential for sperm morphogenesis. The favorable ICSI outcome underscores the clinical importance of genetic diagnosis in CCDC189 ‐related infertility and supports ICSI as an effective therapeutic option for affected couples.