Sex-determining Region Y protein
The sex-determining region Y (SRY) protein is the protein coded for the SRY gene. This protein is also called the testis-determining factor or TDF. The SRY gene that codes for this protein is located on the sex-determining region of the Y chromosome. It is a member of the SOX gene family.
This protein is responsible for the initiation of male sex determination in humans.1 It is also associated with the development of other male characteristics. In humans, the lack of the SRY proteins leads to defective testicular development. For instance, in Swyer syndrome, the XY female has XY karyotype (which is a male karyotype) but with female phenotype. In such case, the individual has the Y chromosome but lacking the SRY gene. A possible cause of the lack of SRY gene is due to an atypical genetic recombination during crossover in meiosis. Normally, the SRY gene stays on the Y chromosome. However, when the SRY gene is transferred to the X chromosome during crossover the resulting Y chromosome would no longer have the SRY gene. The sperm cell with such Y chromosome would produce offspring lacking in SRY protein and may suffer from Swyer syndrome. The paternal X chromosome containing the SRY gene, in turn, may produce offspring with an XX female karyotype but possibly with male characteristics (i.e. testis). This condition is called XX male syndrome.
- SRY protein
1 Berta, P., Hawkins, J. R., Sinclair, A. H., Taylor, A., Griffiths, B. L., Goodfellow, P. N., and Fellous, M. (November 1990). "Genetic evidence equating SRY and the testis-determining factor". Nature. 348 (6300): 448–50.