Differential gene expression during mouse spermatogenesis.

The temporal expression of genes corresponding to eighteen cDNA clones isolated from testis mRNA was analyzed. Two sets of RNA samples were surveyed by means of Northern blot analysis; one set contained poly[A+] RNA from the seminiferous epithelium of mice at different developmental ages and the other contained total cellular RNA from purified germ cells. The purified germ cells represented several morphological stages of spermatogenesis, from spermatogonia to condensing spermatids (steps 12-16) and residual bodies. In this study, four distinct phases of gene expression were observed during spermatogenesis. The clones that were characterized provide molecular markers for stage-specific transcription during germ cell differentiation.