[6] Mutations in this gene lead to a range of disorders of sex development with varying effects on an individual's phenotype and genotype.

[8] SRY gene effects normally take place 6–8 weeks after fetus formation which inhibits the female anatomical structural growth in males.

[11] SRY is a quickly evolving gene, and its regulation has been difficult to study because sex determination is not a highly conserved phenomenon within the animal kingdom.

Within related mammalian groups there are homologies within the first 400–600 base pairs (bp) upstream from the translational start site.

WT1 is transcription factor that has four C-terminal zinc fingers and an N-terminal Pro/Glu-rich region and primarily functions as an activator.

It is not clear how WT1 functions to up-regulate SRY, but some research suggests that it helps stabilize message processing.

[15] However, there are complications to this hypothesis, because WT1 also is responsible for expression of an antagonist of male development, DAX1, which stands for dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1.

It is not clear how DAX1 functions, and many different pathways have been suggested, including SRY transcriptional destabilization and RNA binding.

There is evidence from work on suppression of male development that DAX1 can interfere with function of SF1, and in turn transcription of SRY by recruiting corepressors.

Once in the nucleus, SRY and SF1 (steroidogenic factor 1, another transcriptional regulator) complex and bind to TESCO (testis-specific enhancer of Sox9 core), the testes-specific enhancer element of the Sox9 gene in Sertoli cell precursors, located upstream of the Sox9 gene transcription start site.

[18] SOX9 protein then initiates a positive feedback loop, involving SOX9 acting as its own transcription factor and resulting in the synthesis of large amounts of SOX9.

[15] The SF-1 protein, on its own, leads to minimal transcription of the SOX9 gene in both the XX and XY bipotential gonadal cells along the urogenital ridge.

Part of this up-regulation is accomplished by SOX9 itself through a positive feedback loop; like SRY, SOX9 complexes with SF1 and binds to the TESCO enhancer, leading to further expression of SOX9 in the XY gonad.

Although their exact pathways are not fully understood, they have been proven to be essential for the continued expression of SOX9 at the levels necessary for testes development.

[20] It has been shown, however, that SOX9, in the presence of PDG2, acts directly on Amh (encoding anti-Müllerian hormone) and is capable of inducing testis formation in XX mice gonads, indicating it is vital to testes development.

Atypical genetic recombination during crossover, when a sperm cell is developing, can result in karyotypes that are not typical for their phenotypic expression.

Most of the time, when a developing sperm cell undergoes crossover during meiosis, the SRY gene stays on the Y chromosome.

[22] Individuals with either of these syndromes can experience delayed puberty, infertility, and growth features of the opposite sex they identify with.

[30] This mouse model is being used to investigate the link between SRY and Hirschsprung disease, or congenital megacolon in humans.

[31] This missense mutation causes defective chondrogenesis, or the process of cartilage formation, and manifests as skeletal CD.

These athletes were found to have either partial or full androgen insensitivity, despite having an SRY gene, making them externally phenotypically female.

[37] Despite the progress made during the past several decades in the study of sex determination, the SRY gene, and its protein, work is still being conducted to further understanding in these areas.

There remain factors that need to be identified in the sex-determining molecular network, and the chromosomal changes involved in many other human sex-reversal cases are still unknown.

Both of these studies highlighted the role that SRY plays in the development of the testes and other male reproductive organs.