Not just about sex: throughout our bodies, thousands of genes act differently in men and women
by Jenny Graves, The Conversation:
Most of us are familiar with the genetic differences between men and women.
Men have X and Y sex chromosomes, and women have two X chromosomes. We know that genes on these chromosomes may act differently in men and women.
But a recent paper claims that beyond just genes on X and Y, a full third of our genome is behaving very differently in men and women.
These new data pose challenges for science, medicine and maybe even gender equity.
The human genome
Men and women have practically the same set of about 20,000 genes. The only physical difference in their genetic make up is in the sex chromosomes. Only males have a Y chromosome. Although the X chromosome is present in both sexes, there are two copies in females and only one in males.
The human Y contains only 27 genes. One of these is the sex-determining region Y gene (SRY), which kick-starts the pathway that causes a ridge of cells in a 12 week-old embryo to develop into a testis.
Until recently, many believed that only the presence or absence of SRY distinguishes men and women.
Writing previously, I pointed out that there are 26 other genes on the Y chromosome, and perhaps another hundred or so genes on the X chromosome that are active in two doses in women and a single dose in men. I speculated that there may be a few hundred more genes directly affected by these X or Y genes, or by the hormones that they unleash.
This new paper suggests I underestimated by a huge margin.
Related Posts
Tags
Share This
