Human Testis Protein Of Nyd-sp16 Functional Studies

In previous studies, by using human testis cDNA microarray and differentially hybridization with adult and embryo testis cDNA probes, a novel gene expressed highly in adult testis was cloned and named as NYD-SP16. Sequence analysis showed that highly level of homology (>80%) between NYD-SP16 and the mouse testis cDNA AK006554 in nucleotide and protein level(NYD-SP16 protein and mouse testis protein BAB24651 encoded by AK006554). Therefore, NYD-SP16 is a human-mouse homologous gene. NYD-SP16 protein is a transmembrane protein and found to be associated with spermatogenesis.Given the high homology between human NYD-SP16 and its mouse homologue, we used mouse NYD-SP16 as a model to characterize and further elucidate the functional role of this protein. Our data demonstrate that in mouse testis, NYD-SP16 was immunolocalized to elongating spermatids with a polar pattern on head side. Immunoreactivity in mouse sperm was mainly seen in the acrosomal region while chlortetracycline (CTC) analysis and immunofluorescence counterstaining suggest that this expression pattern was not altered in capacitated sperm. However, after acrosome reaction (AR), the intensity of the fluorescence staining attenuated significantly. NYD-SP16 antiserum significantly inhibited mouse sperm capacitation and AR in a concentration-dependent manner...