Testis-specific transcriptional control.

In the testis, tissue-specific transcription is essential for proper expression of the genes that are required for the reproduction of the organism. Many testis-specific genes are required for mitotic proliferation of spermatogonia, spermatocytes undergoing genetic recombination and meiotic divisions, and differentiation of haploid spermatids. In this article we describe some of the genes that are transcribed in male germinal cells and in non-germinal testis cells. Because significant progress has been made in examination of promoter elements and their cognate transcription factors that are involved in controlling transcription of the testis-specific linker histone H1t gene in primary spermatocytes, this work will be reviewed in greater detail. The gene is transcriptionally active in spermatocytes and repressed in all other germinal and non-germinal cell types and, therefore, it serves as a model for study of regulatory mechanisms involved in testis-specific transcription.