SRY, short for sex-determining region Y gene, is a crucial gene located on the Y chromosome that plays a primary role in sex determination in mammals.
Function of the SRY Gene
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Sex Determination: The SRY gene initiates male sex determination. When present and functional, it triggers the development of testes in the developing embryo. In the absence of a functional SRY gene, the default pathway of female development is followed.
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Mechanism of Action: The SRY gene encodes a protein called the sex-determining region Y protein, also known as the testis-determining factor (TDF). This protein is a transcription factor, meaning it binds to specific DNA sequences and regulates the expression of other genes.
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Testis Development: The SRY protein specifically binds to DNA, causing it to bend and distort. This interaction likely alters the expression of genes involved in the development of the testes. It initiates a cascade of events that ultimately leads to the formation of Sertoli cells, which are essential for testis development.
Significance
The discovery of the SRY gene was a major breakthrough in understanding sex determination. It provided a molecular explanation for why individuals with a Y chromosome typically develop as males, while those without a Y chromosome develop as females.
Clinical Relevance
Mutations or deletions in the SRY gene can lead to sex reversal, where an individual with a Y chromosome develops as a female (Swyer syndrome). Conversely, translocation of the SRY gene to an X chromosome can result in an individual with two X chromosomes developing as a male.
