I guess we came to the stage where you want to tell me "it's not only SRY", then enlighten me about AIS, and Klinefelter, right? You can re-read the branch and

I guess we came to the stage where you want to tell me "it's not only SRY", then enlighten me about AIS, and Klinefelter, right? You can re-read the branch and make sure I made no claim that there's a particular gene which is the discriminant, the talk is about genes expression. Which is a very important distinction. FWIW we could knew nothing about DNA, chromosomes, and genes, and still be clearly able to distinguish between man and woman. Because whatever the cause the result is remarkably binary! It's so basic that infants of 4-5 month old already can reliably tell it apart - before culture would affect us. On the contrary, it takes years of social pressure and indoctrination to start playing Emma Watson, and pretend being unable to see it. This clarification should answer all your questions, but here them anyway: 1. No, in the absolute majority of cases you don't need to have gene test cause it's apparent enough. At the newborn stage we mostly look at genitals, then the farther it goes though the less it's needed. There are ideological wars waged about genitals, but in reality it predicts the development with amazing reliability. However, In extremely rare cases medical/legal disputes may force someone to make them though. 2. Chimeric people are men and women. Cause it's expression not presence of genes which builds us. 3. People with transplants are developed as men, and women. 4. As already said with infants we look at genitals. With farther development sex differences become easily perceptible even with fully clothed humans. Even in Arctic climate! (Trust me I've been there) 5. I never heard of fully developed human organism to undergo a re-development with CRISPR or otherwise. I'm open for the new facts though if you have any. 6. Blocking gene(s) expression matters for sure, that's how we get AIS.