Downstream genes of Sox8 that would affect adult male fertility.

Sertoli cells provide nutritional and physical support to germ cells during spermatogenesis. Sox8 encodes a high mobility group transcription factor closely related to Sox9 and Sox10. Sertoli cells produceSOX8 protein, and its elimination results in an age-dependent deregulation of spermatogenesis resulting in male infertility. This suggests that Sox8 is a critical regulator of Sertoli cell function for the maintenance of male fertility beyond the first wave of spermatogenesis. To better understand the roles of Sox8 in testicular development and maintenance of male fertility, we have performed a detailed analysis to explore its downstream genes. We have used mRNA expression profiling to identify affected genes in Sertoli cells in the mutant testes of 2-month-old mice. Expression profiling of the heterozygous and homozygous Sox8 mutant testes indicates alterations in several important spermatogenesis and blood-testis barrier genes, providing insight into the molecular basis of the defects in Sox8(-/-) testes beyond the first wave of spermatogenesis.