Analysis of male sterile mutations in the mouse using haploid stage expressed cDNA probes.

A differential hybridization screening procedure has identified cDNAs which correspond to RNAs which are expressed in mouse testis and at lower levels in liver and spleen. The sensitivity of this procedure is such that approximately 0.5% of 1.4 X 10(4) cDNA clones are revealed as "testis specific". We have focused on ten cDNA clones which have been used to identify RNAs expressed in the haploid phase of spermatogenesis. Using Northern blots to analyse RNA isolated from the testes of mutant mice (Tfm/Y and Sxr/+) blocked at specific stages in spermatogenesis or RNA from sexually immature mice, 8 clones have been identified which correspond to RNAs expressed uniquely or at much higher levels in meiotic or post meiotic cells.