Here’s one that deserves a post of its own. Some scientists in Heidelberg have been doing some fairly awful things to lady mice, but their results are very interesting. The story revolves around a sneaky gene called FOXL2. If you turn it off before birth then the mice’s ovaries do not develop properly, but if you turn it off in adult female mice their ovaries suddenly start pumping out testosterone just like good like testes.
Nature has a good overview of the research. The Independent is somewhat over the top in claiming that this explains everything from bearded ladies to transsexuals, but the paper did have a very good headline while I have shamelessly stolen. Also it is true to say that this is yet another nail in the coffin of the ridiculous idea that everything about one’s sex and gender is fixed from conception by one’s chromosomes.
Possibly the most interesting thing about the research, especially if you are a lesbian or a feminist science fiction writer, is the prospect that the modified ovaries might actually be able to produce sperm. Yes, that’s right, you might be able to take a normal adult woman, tweak the genes in her ovaries, and make her produce sperm. If you could do it without subjecting her to all of that testosterone, so much the better, assuming that she’s happy as a woman. The technique might also one day provide an interesting option for female-to-male transsexuals because they could make their own testosterone.