Analysis of stage-specific protein synthesis during spermatogenesis of the mouse by two-dimensional gel electrophoresis

Cells were labelled by intratesticular injection of [35S]methionine. After 14-16 h the relative rates of incorporation of label in spermatocytes, early spermatids and late spermatids were 10:2:1 respectively. Approximately 15% of the soluble (100 000 g supernatant) and 20% of the particulate proteins solubilized by NP-40 (from the 100 000 g pellet) that were detectable on two-dimensional gels showed stage-specific synthesis. A large number of proteins were detectable only in post-meiotic cells and may be valuable for studying the control of gene expression in haploid cells.