The group of Dr. Dagmar Wilhelm at Queensland University have found a gene that could be the potential target for Sry action during sex determination. They immunoprecipitated this fragment from E11.5 dpc gonads using anti-Sry antibody specific to mouse. The approach they have used is novel and there are other potential candidate genes in the list, which they will slowly be characterizing.

The Cerebellin 4 Precursor Gene Is a Direct Target of SRY and SOX9 in Mice
Bradford ST, Hiramatsu R, Maddugoda MP, Bernard P, Chaboissier MC, Sinclair A, Schedl A, Harley V, Kanai Y, Koopman P, Wilhelm D.
Biol Reprod. 2009 Feb 11. [Epub ahead of print]

In most mammals, the expression of SRY (sex-determining region on the Y chromosome) initiates the development of testes and thus determines the sex of the individual. However, despite the pivotal role of SRY, its mechanism of action remains elusive. One important missing piece of the puzzle is the identification of genes regulated by SRY. In this study we used chromatin immunoprecipitation to identify direct SRY target genes. Anti-mouse SRY antibody precipitated a region 7.5 kb upstream of the transcriptional start site of cerebellin 4 precursor (Cbln4), which encodes a secreted protein. Cbln4 is expressed in Sertoli cells in the developing gonad with a profile mimicking that of the testis-determining gene Sox9 SRY-box containing gene 9). In transgenic XY mouse embryos with reduced Sox9 xpression, Cbln4 expression also was reduced, whereas over-expression of Sox9 in XX mice caused an up-regulation of Cbln4 expression. Finally, ectopic up-regulation of SRY in vivo resulted in ectopic expression of Cbln4. Our findings suggest that both SRY and SOX9 contribute to the male-specific up-regulation of Cbln4 in the developing testis, and identified a direct in vivo target gene of SRY.

Article link: http://www.ncbi.nlm.nih.gov/pubmed/19211811?