Contrary to Old Thinking, The Default Sex Gender Gene May Be Male

For every woman who thought she had her own pair of brass balls under that crinoline skirt, she just got a big boost from Mother Nature.

Photo via Riverside Online

Science Daily reports an amazing piece of research that turns prior assumptions about how an individual’s sex (gender) is determined inside out. You are probably aware that females have two X chromosomes and males one X and a Y.

Scientists had long assumed that the female pathway — the development of ovaries and all the other traits that make a female — was the default gender.

In adult animals at least, it is the male pathway that needs to be actively suppressed, as Mathias Treier and his team at EMBL discovered.

A gene called Foxl2, which is located on an autosome — a chromosome other than the sex chromosomes — and therefore present in both sexes, was known to play an important role in the female pathway, but its precise function remained elusive. To elucidate the matter, Treier and colleagues ablated, or ‘turned off’, this gene in the ovaries of adult female mice.

“We were surprised by the results,” says Treier, “We expected the mice to stop producing oocytes, but what happened was much more dramatic: somatic cells which support the developing egg took on the characteristics of the cells which usually support developing sperm, and the gender-specific hormone-producing cells also switched from a female to a male cell type.” via Science Daily

Thus, the scientists discovered that Foxl2 plays a crucial role in keeping female mice female, because they could easily become male.

This research discovery may be related to the “how did he do that?” question governing the ability of Japanese professor Tomohiro Kono to manipulate female mouse eggs to perform like sperm. In this research the mice born from two females — with the eggs of one manipulated — lived 30 percent longer than male/female mice.

Bottom line, science is doing some incredible research on gender-based DNA. Another reported consequence of the research is that researchers will learn how to “switch off” a woman’s ovaries, allowing her to put off having babies until even later in life. See Marie Claire.