Expression Profile of Sox5 and Sox6 in Sertoli and Spermatogonial Cells in Growing Mice Testis

SRY box genes are peculiar to animal kingdom. They are involved in many processes particularly sex determination and testes development in male embryo. Although Sox family genes have been identified in various cells, their expression pattern and role is not entirely recognized in Sertoli cells. In this research, we focused on the expression of SoxD group Sox5 and Sox6 genes in Sertoli cells of mice during pre- and post-pubertal testicular development ranging from one-week-old to eight-week-old mice. The expression was studied by immunohistochemistry on whole testes, and qPCR to determine the mRNA level of all age groups, while immunocyto-chemistry was performed for localization in specific age groups. qPCR results of Sertoli cells from first week to eight week showed different levels of expression. The mRNA level of Sox5, during pre-pubertal age, was significantly high (P<0.001), but as the age progressed, the expression became low. Conversely, Sox6 was initially expressed faintly, but at the pubertal age, the expression rose significantly (P<0.001). Furthermore, the expression signals of both genes on spermatogonial cells were also found strong. The study shows that Sox5 and Sox6 are expressed during postnatal and pubertal periods and may play a vital role in the maturation of spermatozoa. In addition, they overlap to regulate multiple functions like spermatogenesis and steroidogenesis in testes.