What is the outcome of the germinal ridge when a Y-chromosome is present?

The presence of a Y chromosome initiates the development of male sexual characteristics during embryonic development. Specifically, the SRY (Sex-determining Region Y) gene located on the Y chromosome plays a crucial role in this process. When the germinal ridge, which initially has the potential to develop into either ovaries or testes, contains a Y chromosome, it activates the SRY gene. This activation leads to the differentiation of the germinal ridge into testes.

As the testes develop, they produce male hormones, including testosterone and anti-müllerian hormone (AMH), which further direct the formation of male reproductive structures and suppress the development of female structures. Therefore, the outcome of the germinal ridge in the presence of a Y chromosome is the differentiation into testes, establishing male characteristics and reproductive function.