Expression and Phosphorylation of Rad17 Checkpoint Protein during Spermiogenesis in Mouse Testis

Abstract: Rad17 is one of critical checkpint proteins in cell cycle checkpoint singling pathways and plays vital roles in DNA damage checkpoint and DNA replication checkpoint. However， the role of Rad17 in meiotic checkpoint is poorly understood. Since meiosis is very active in adult testis， we investigated the expression and phosphorylation change of Rad17 in mouse testis at different stages by Western blot analysis， and examined the expression of Rad17 in the germ cells at different meiotic stages in testis by Immunohistochemistry. Our results revealed that Rad17 protein was overexpressed in mouse testis tissues， while other tissues such as liver and kidney expressed much lower Rad17. Although Rad17 expression remained high level in mouse testis at different development stages， the phosphorylation level of Rad17 was significantly increased after four weeks of birth. Immunohistochemical analysis indicated that Rad17 protein was present primarily in the nuclei of spermatogonia and spermatocyte， and disappeared in the matured spermatids. These results showed that Rad17 also played an important role in meiotic checkpoint during germline development in testis.

CSTR: 32200.14.cjcb.2005.04.0018