Expression of SRY proteins in both normal and sex-reversed XY fetal mouse gonads.

Sry, a single-copy gene on the Y-chromosome, acts dominantly to trigger differentiation of a testis from a gonadal primordium that otherwise develops into an ovary in mammals. Sry encodes a protein with a DNA-binding domain and probably acts as a transcription factor. However, the mode of SRY action in testis determination remains largely unknown.