MCD BIO CM156 Lecture Notes - Lecture 10: Human Genetics, Sexual Differentiation, Y Chromosome
12 Feb 2020
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Old and new views of sex chromosome function. Hybrid model for the influence of sex chromosomes on male and female biology. New: 10 different y genes expressed thoughout the body throughout the body xx doesn"t equal xy. Old: y functions only in the gonad, outside the gonad, xx and xy cells are functionally equivalent, in females, second 2 is transcriptionally silent. Experiment: added species and examined them for sex differentiation. Some sex-biased expression is conserved across species, some is not. Some species while secrete hormones from glands to signify differences. Individual cells that have xx vs xy have very different gene expression. Conserved sex bias in autosomal gene expression contributes to sex differences in human height. Despite overlap, there is a difference of 13cm in height. Evidence for sex chromosome influences on body size. Male/female differences precede puberty and high gonadal hormone levels suggests intrinsic genetic basis.
