Subcellur location of bovine Sry and its regulation on Sox9 expression

This study attempted to identify the putative targets of Sry in the process of bovine sex-determination and to analyze the localization of Sry protein in cells. The Sry gene was overexpressed by transfecting pcDNA3.1-Sry in primary cultured genital ridge cells and granulosa cells, and six genes which were identified as important in sex determination in mammals were analyzed, including Sf1 (Steroidogenic fator-1), Gata4 (GATA binding protein 4), Wt1 (Wilms’ tumor gene), Sox9 (Sry-related HMG box-9), Amh (Anti Mullerian Hormone), and Dax1 (Dosage sensitive sex reversal locus-1). Subcellular localization of the expressed Sry protein in genital ridge cells and granulosa cells was also analyzed. When Sry was overexpressed, significant increases of Sox9 mRNA expression were observed in genital ridge cells (P<0.01), but not in granulosa cells. Other gene expressions checked were not affected by Sry overexpression. Subcellular localization analyses indicated that Sry protein was mainly detected in the nuclei of both genital ridge cells and granulosa cells. Our results indicated that Sry might regulate Sox9 indirectly, or there might be another regulatory pathway for Sox9 expression without the involvement of Sry. Sry probably works as a transcription factor in bovine sex determination [Acta Zoologica Sinica 54(5): 890– 896, 2008].