Genes involved in spermatogenesis

During mammalian spermatogenesis, primordial germ cells develop into spermatogonia, giving rise to spermatocytes that undergo two meiotic divisions to become round spermatids. These cells differentiate into spermatozoa during spermiogenesis. Spermatogenesis is a complex process of cell differentiation controlled by many factors, among which gene regulation in the spermatogenic cells plays a pivotal role. Genes important for male gametogenesis involved in highly con-served landmark events such as meiotic recombination, formation of the synaptonemal complex, sister chromatid cohesion, spermiogenesis during postmeiotic stages, and checkpoints and factors required for the meiotic cell cycle. Spermatogenesis is characterized by phase-specific expression of many genes exclusively expressed in the spermatogenic cells. With the development and application of technologies like gene cloning, gene expression and functional characterization, many spermatogenesis-related genes have been found in the past few years, and some of them have been proved to play an important role in spermatogenesis. Here, we review the advances in this field with an emphasis on spermatogenesis-associated genes such as cyclins, proto-oncogenes, azoospermia factor genes, cytoskeleton genes, heat shock genes, nucleoprotein transition genes, centrin genes and apoptosis genes.