How does the SRY gene influence male sex differentiation?

The SRY gene, or Sex-determining Region Y gene, plays a crucial role in male sex differentiation by initiating the formation of male characteristics. When the SRY gene is expressed, it triggers a cascade of events that leads to the development of testes rather than ovaries. The testes then produce hormones, particularly testosterone, which promotes the development of male physical characteristics and suppresses the development of female characteristics. This includes the inhibition of structures that would typically form the female reproductive system, such as the Müllerian ducts.

This mechanism is pivotal in establishing male sex characteristics during embryonic development. The SRY gene's primary function is not only to guide the differentiation towards testes but also to ensure that features typically associated with females do not develop in the presence of male genetics. Therefore, the influence of the SRY gene in suppressing the emergence of female characteristics is essential for the proper differentiation into male sex.