FUNCTIONAL-ROLE FOR THE C-ABL TYROSINE KINASE IN MEIOSIS I

The c-Abl tyrosine kinase is activated by ionizing radiation and certa in other DNA-damaging agents. The DNA-dependent protein kinase (DNA-PK ) and the ataxia telangiectasia mutated (ATM) gene product, effecters in the DNA damage response, contribute to the induction of c-Abl activ ity. The present study demonstrates that c-Abl is expressed in mouse a nd rat testes, and predominantly in pachytene spermatocytes of meiosis I. The results also demonstrate that c-Abl interacts directly with me iotic chromosomes. In concert with a requirement for c-Abl at the pach ytene stage, me show that, in contrast to wild-type mice, testes from Abl(-/-) mice exhibit defects in spermatogenesis. These findings provi de the first demonstration that c-Abl plays a functional role in meios is.