Draft:SRY- Master Regulator of Sexual Determination

SRY is the transcription factor responsible for sexual differentiation that leads to the formation of either ovaries or testes. During the early stages of development, there is one of two undifferentiated gentetal ridges that either contains the essential cells to become sertoli cells or granulosa cells (Kashimada & Koopman, 2010). SRY upregulates Sox9 which then upregulates Fgf9 which in turn will enter a positive feedback loop with each other. Sox9 drives the formation of the testes and the supporting cells that are needed for the male reproductive system. If SRY is absent, this process does not occur and other genes that are responsible for the development of the ovaries are able to take over. SRY is the master regulator of sexual determination because its presence is the ultimate driver of sexual determination of the fetus. The main disease associated with SRY is Swyer Syndrome. Swyer syndrome is when a female who expresses the genitalia of a female and is phenotypically female also has a streak gonad and a 46 XY karyotype (Meyer et al., 2019). These females will have to undergo surgery to remove this structure due to its high affinity for cancer to develop. There is a knockout model for SRY done in pigs. Through the use of CRISPR technology the SRY gene was knocked out in male pigs. The research showed that with the absence of SRY, both the internal and external genitalia were reversed and when the piglets were born they were a genotypic male but expressed female genitalia (Kurtz et al., 2021). This study highlighted the role of SRY in sexual determination.