sex and inheritance

Question	Answer
SRY	(Sex-determining region Y) is gene on the Y chromosome. This intronless gene encodes a transcription factor that initiates male sex determination. allows bipotential primordial gonad cells to differentiate and proliferate
although SRYis the trigger to sexual differentiation, other genes are also involved, these include	1. FTZ-F1 (SF-1) 2. SOX9
Is Sox9: an SRY-target gene? - EVIDENCE	1. Sox9 expression is strongly upregulated soon after the expression of SRY begins, whereas it is downregulated in the ovary 2. SRY-positive cells exclusively become SOX9-positive Sertoli cells
SRY gene encodes a gene that affects	testicular differentiation.
Following Sry activation and testes development	male determining signal is sent out via two factors, anti-Mullerian hormone (from sertoli cells) and testosterone. these cause the major differences between males and females.
All other differences between sexes are secondary and due to	‘turning on’ of genes encoding hormones or factors produced by the gonads.
In the absence of a signal (testis determining factor)	ovaries are formed.
The primary event of sex determination is the	differentiation of this gonadal tissue into testes rather than ovaries. Differentiation of gonadal tissue causes a male determining signal to be sent out via anti-Mullerian hormone and testosterone

Resource summary

	Created by lumen7 almost 11 years ago