Stage and developmental specific gene expression during mammalian spermatogenesis.

Spermatogenesis is a complex developmental process which involves amplification of germinal stem cells, their differentiation into spermatocytes, meiotic division and finally transformation into mature spermatozoa. Therefore, spermatogenesis provides an interesting system for examining the regulation of gene expression during development and differentiation. The genes expressed during spermatogenesis can be divided into two main groups: diploid and haploid expressed genes. In this review, we report about the regulation of expression of a diploid expressed gene, namely the proacrosin gene, and that of a haploid expressed gene, the transition protein 2 gene.