Biology subjects

Yap, Y. T.

Publications and source records attributed to Yap, Y. T..

3 recordsLinked to original sources

bioRxiv2025

COPS5 is Essential for Sertoli Cell Function and Male Fertility in Mice

The COP9 signalosome subunit 5 (COPS5) is a multifunctional protein that regulates ubiquitin-dependent processes. Global knockout of Cops5 is embryonically lethal, and while it is known to be vital in germ cells and testicular smooth muscle, its function in Sertoli cells, the key somatic supporters of spermatogenesis, remains entirely unknown. This study investigates the critical role of COPS5 within Sertoli cells. Using Sertoli cell-specific Cops5 knockout mouse models, we demonstrate that COPS5 is essential for maintaining male fertility. Sertoli-specific Cops5 ablation resulted in age-dependent male infertility, despite normal initial development. Mutants exhibited progressive testicular atrophy, oligoasthenospermia, and significantly reduced testis weight. Histology showed vacuolated, disorganized tubules devoid of germ cells and sperm. Crucially, COPS5 loss disrupted Sertoli cell polarity, evidenced by aberrant cytoplasmic mislocalization of the nuclear marker WT1 and detachment from the basement membrane. Integrity of the blood-testis barrier (BTB) was severely compromised, with discontinuous and punctate expression of the tight junction adaptor ZO-1. Intercellular communication was also impaired, shown by a stark reduction in Connexin 43 gap junction signals. Our findings establish that COPS5 is an indispensable intrinsic regulator of Sertoli cell function. Its loss disrupts cell polarity, BTB architecture, and gap junction communication, leading to failed support of spermatogenesis and consequently infertility. This work defines a novel and critical somatic function for COPS5 in male reproduction. We conclude that COPS5 is intrinsically required in Sertoli cells to maintain their polarity and BTB function, which are foundational for supporting germ cell development and ensuring male fertility. This identifies COPS5 as a novel, essential regulator within the testicular somatic compartment.

genetics↗

bioRxiv2025

Two Spag6 genes control sperm formation and male fertility in mice

Sperm-associated antigen 6 (SPAG6) is the mammalian orthologue of Chlamydomonas PF16, a central axonemal protein essential for flagellar motility. In mice, two homologous genes have been identified: the ancestral Spag6 on chromosome 2 and the evolutionary derived Spag6l on chromosome 16. Although Spag6 knockout mice (Spag6-/-) are phenotypically normal, the surviving Spag6l-/- males are infertile. To further investigate the roles of SPAG6 and SPAG6L, we generated compound mutants by crossing the two knockout lines. Compound heterozygous Spag6+/-; Spag6l+/- mice are fertile, while all Spag6-/-; Spag6l+/- males are infertile despite grossly normal appearance. Histological and ultrastructural analyses revealed defective spermiogenesis, including abnormal chromatin condensation, malformed acrosome and manchette, and disorganized mitochondrial and fibrous sheath. Both SPAG6 and SPAG6L bind to SPINK2, a key regulator of acrosome function, but SPAG6 has an approximately 10-fold higher binding affinity than SPAG6L. Moreover, SPAG6 modulates testicular AKAP4 and SPAG16L levels, which are critical components of the fibrous sheath and central apparatus respectively. Notably, SPAG6 suppresses tubulin acetylation, whereas SPAG6L enhances this post-translational modification, suggesting antagonistic roles in microtubule assembly. Overall, our findings demonstrate that SPAG6 and SPAG6L coordinately regulate sperm formation and male fertility during evolution.

developmental biology↗

bioRxiv2022

MEIG1/PACRG associated and non-associated functions of axonemal dynein light intermediate polypeptide 1 (DNALI1) in mammalian spermatogenesis

Axonemal dynein light intermediate polypeptide 1 (DNALI1) was originally cloned from Chlamydomonas reinhardtii in an effort to find motor proteins essential for flagellar motility. Here we report that DNALI1 is a binding partner of parkin co-regulated gene 1 (PACRG), which forms a complex with meiosis expressed gene 1 (MEIG1) in the manchette, a transient and unique structure only present in the elongating spermatids and required for normal spermiogenesis of the male germ cell differentiation process. DNALI1 recruits the PACRG protein in transfected CHO cells, and also stabilizes PACRG in bacteria and transfected mammalian cells. The untagged DNALI1 could also be co-purified with His-tagged PACRG in the gel filtration assay. Immunofluorescence staining on isolated male germ cells revealed that DNALI1 was present in the manchette of elongating spermatids, and colocalized with PACRG in this structure. In Pacrg mutant mice, localization of DNALI1 in the manchette was not changed, suggesting that DNALI1 and PACRG form a complex in the manchette, with DNALI1 being an upstream molecule. Mice deficiency in DNALI1 specifically in male germ cells showed dramatically reduced sperm numbers and were infertile. In addition, majority of the sperm exhibited abnormal morphology including misshapen heads, bent tails and enlarged midpiece, discontinuous accessory structure, and loss of sperm individualization, emphasizing the importance of DNALI1 in sperm development. Examination of testis histology revealed impaired spermiogenesis in the conditional Dnali1 knockout mice. Electron microscopy revealed disrupted ultrastructure in sperm of the Dnali1 mutant mice. Testicular levels of MEIG1, PACRG and SPAG16L proteins were not changed in the Dnali1 mutant mice. However, MEIG1 and SPAG16L were no longer present in the manchette in the absence of DNALI1. These findings demonstrate that DNALI1 is involved in the connection of the MEIG1/PACRG complex to carry cargo proteins along the manchette microtubules for sperm flagella formation. Given that Dnali1 mutant mice showed impaired sperm individualization that was not observed in the MEIG1 nor PACRG-deficient mice, DNALI1 might fulfill other functions beyond its role associated with the MEIG1/PACRG complex. Thus, DNALI1 plays multiple roles in sperm cell differentiation and function. Summary statementAxonemal dynein light intermediate polypeptide 1 (DNALI1) is required for sperm formation and male fertility. It associates with the MEIG1/PACRG complex in the manchette and is involved in a cargo transport system. In addition, it might be related to IFT and sperm individualization.

cell biology↗