Expression Characteristics And Cloning Of Mouse Spermatogenesis-related Genes

Mammalian Spermatogenesis is a unique cell differentiation process and can be divided into three stages: mitosis, meiosis, and spermiogenesis. Primitive type A spermatogonia differentiate to form primary spermatocytes. The primary spermatocytes enter first meiosis after DNA replication for last time and give rise to two secondary spermatocytes, which then undergo second meiosis without DNA replication and form haploid round spermatids. Subsequently, these cells enter spermiogenesis and undergo histone-protamine replacement reaction, nuclear condensation, and major morphological changes to form completed spermatozoa. The whole process of male germ cell differentiation from spermatogonial stem cells into sperm is under control of many different molecules including hormones and growth factors. Although the extrinsic regulators are well understood, the molecular mechanisms of spermatogenesis remain unclear and the underlying key molecules controlling spermatogenesis have remained elusive. Our group has tried to identify the key genes regulating spermatogenesis by studying the expression characteristics and functions of genes during spermatogenesis. Our findings may provide insight into molecular mechanisms of spermatogenesis. This present study includes three parts.1. Stage-specific and tissue-specific expression characteristics of differentially expressed genes during mouse spermatogenesis. Different types of spermatogenic cells and spermatozoa were isolated from Balb/c mice testes and epididymis, and Atlas cDNA arrays containing 1176 known mouse genes were used to determine the gene expression profiles of the cells (primitive type A spermatogonia, type B spermatogonia, preleptotene spermatocytes, pachytene spermatocytes, round spermatids, and elongating spermatids) and spermatozoa. The expression of 260 genes were detected in all stages of spermatogenic cells. Of them, a number of genes showed differential expression. The 28 differentially expressed genes were further analyzed by reverse transcription polymerase chain reaction...