The Fuction Of Cdc20in The Spermatogenesis Of Mouse

Spermatogenesis is a complex process of cell division and differentiation. In the seminiferous tubules of mouse, male gametes experience three stages of morphological and functional transition. First, gametes transform into a number of cells termed spermatogonia, and from the spermatogonia the primary spermatocytes are derived, then the spermatocytes undergo meiosis, producing a number of spermatids, Each primary spermatocyte divides into two secondary spermatocytes, and each secondary spermatocyte into two spermatids, These spermatids develop into mature spermatozoa by spermiogenesis. It involves mitosis and meiosis in the process of spermatogenesis, and the correct separation of chromosomes in mitosi and meiosis is crucial for the health sperm production.In this study, we used Cdc20engineering mouse models to study the function of Cdc20in the spermatogenesis of mouse. Previous study has shown that:Cdc20is most abundant in the cytoplasm of pachytene spermatocytes, while it is also detected in spermatocytes undergoing meiosis and in round and condensing spermatids, but undetectable in early elongating spermatids. We used hematoxylin and eosin staining(HE), Immunohistochemistry, immunofluorescence and TUNEL assay as the methods to explore the reason of the spermatogenesis failure. Immunohistochemistry and immunofluorescence showed that the spermatogenesis of Cdc20+/AAA and also the Cdc20+/-is normal. But, the spermatogenesis of the Cdc20AAA/-mice impaired. There are no spermatozoa in the testis and epididymis. To reveal the reason of the spermatogenesis failure, we performed the same experiments described as above, It was found that when the mouse is7days old, the development of the spermatogonia in Cdc20AAA/-testes. At14days, Cdc20AAA/-mice produced spermatocytes as the control mouse do. At21days, though there are round spermatids in the Cdc20AAA/-testis, their number ignificantly. At28days, no elongating spermatids are developed in the Cdc20AAA/-testes, but the control mouse produced spermatids normally. At35days, there are spermatozoa in the control testis and epididymis, while no spermatozoa can be observed in the Cdc20AAA/-testes and epididymis. All the above evidences indicated that spermatogenesis failure of the Cdc20AAAA/-mouse is caused by abnormal meiosis. We also detected the apoptosis of testis cells, by TUNEL assay The result shows there had more apoptosis in the Cdc20AAAA/-testes.In conclusion, the present studies indicate that the spermatogenesis failure of Cdc20AAA/-mouse is caused by the abnormal meiosis.