New gene found that determines physical sexuality

[SplitDik (imported)]

This is interesting. They've found that it is not just the XY chromosomes that can determine if you become physically male. May have some implications for therapy for transgender or hermaphroditic situations.

http://www.timesonline.co.uk/tol/news/s ... 952050.ece

December 11, 2009

Scientists find single ‘on-off’ gene that can change gender traits

Hannah Devlin

Scientists have identified the gene that keeps females female. An international team found that the action of a single gene is all that stops females from developing male physical traits, including testes and facial hair.

When this gene was artificially “switched off” in adult female mice their ovaries began to turn into testes and they started to produce a level of testosterone found in healthy male mice.

The discovery could eventually revolutionise gender reassignment therapy and improve treatments for babies who are born with a mixed gender.

The research, published today in the journal Cell, challenges a common perception that gender is determined purely by the X-chromosomes and Y-chromosomes. The gene that was switched off, known as FOXL2, lies on a non-sex chromosome that is shared by males and females.

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“We take it for granted that we maintain the sex we are born with, including whether we have testes or ovaries. But this work shows that the activity of a single gene, FOXL2, is all that prevents adult ovary cells turning into cells found in testes,” said Robin Lovell-Badge, from the National Institute for Medical Research, a co-author of the paper.

The gene appears to have a “see-saw” relationship with another gene, SOX9, which is normally active only in males. When one is on, the other is automatically off. In the first few days of male development SOX9 is turned on, and this stops FOXL2 from becoming active for the rest of the man’s life. The reverse occurs in females, with FOXL2 being switched on first.

The discovery that gender depends, at least in part, on the competing action of genes that are shared by both sexes suggests that gender can be more easily manipulated than previously thought.

FOXL2 was already known to be important for the growth of ovaries during development and for their maintenance during a woman’s life. However, scientists did not anticipate that egg-producing cells in the ovary could be co-opted by a competing male gene to carry out the male reproductive functions.

“We expected the mice to stop producing eggs, but what happened was much more dramatic,” said Mathias Treier, of the European Molecular Biology Laboratory, who led the study.

Using genetic engineering techniques, the FOXL2 gene was switched off in adult female mice. Any developed eggs in the ovary died. Follicles, which eventually grow into eggs, slowly transformed into cells that looked like Sertoli cells, which produce sperm in the testes.

After the genetic therapy, the female mice also developed testosterone-producing cells, and their levels of testosterone surged.

The physical effects of this were harder to assess as male and female mice have fewer distinctive traits — there is no difference in hairiness, for instance, and little difference in size. However, the scientists anticipate that in humans the effect would be similar to when testosterone is given in tablet form. In gender reassignment therapy this causes females to lose developed breasts and grow beards. Their voices deepen too.

Apart from the changes to their reproductive organs, the mice showed no signs of adverse effects and had a normal lifespan.

The researchers anticipate that temporarily suppressing SOX9 in males would have the opposite effect. Turning it off would automatically trigger the ovary development gene to come on, leading to cells in the testes turning into follicles and ceasing the production of testosterone.

Applying the therapy in humans is a long way off, but the researchers say that it could dramatically improve clinicians’ ability to change a person’s gender. Rather than be placed on medication for the rest of their life, only a short course of gene therapy would be required.

[Arab Nights (imported)]

I would change the name from FOX (l2) to the O'Leary Factor.

[twaddler (imported)]

Wow, this certainly sounds really interesting! Screw finding a gender therapist, find me a gene therapist!

[Elizabeth (imported)]

Well, this certainly could be good news for FtM transsexuals. They would no longer need hysterectomies or T shots. They could turn their ovaries into testosterone producers.

It will be interesting to see if this works in reverse. If I could turn my testicles into estrogen producers, they would be worth keeping. Perhaps permanantly tucked inside. Who knows, maybe they may even end up producing eggs.

Like I said, it will be interesting to see how this shakes out.

Elizabeth

[bobberlove (imported)]

One can now imagine what the world will look like in five hundred years. The global warming will cause populations to shift inland. Unisex families will be the norm and families created by humans, but their sex determined by a "Big Brother" computer. I could go on but the prospects of Earth's future being controlled by science is frightening to me.

[devi (imported)]

Wow, this certainly sounds really interesting! Screw finding a gender therapist, find me a gene therapist!

Gene therapy would still be of no or little use until all of the prohibitive costs and measures of Harry Benjamin and all of the greediness of shrinks and surgeons could be removed. Fact is you would still have a small lump however tiny that it is in your pants and possibly some facial hair from before and a birth certificate which is next to impossible to change. With many this gene change does occur naturally but because of the constructs of modern western culture it is much easier for a full testosterone natural male to make the switch than for someone who is in-between.

[Tclosetgirl (imported)]

I'd rather convert my testes to ovaries!

[gareth19 (imported)]

One can now imagine what the world will look like in five hundred years. The global warming will cause populations to shift inland. Unisex families will be the norm and families created by humans, but their sex determined by a "Big Brother" computer. I could go on but the prospects of Earth's future being controlled by science is frightening to me.

And you are not afraid of the earth's future being controlled by ignorance, blind luck, or creationists?

[Hash (imported)]

Wow, o.k., testicles turn into ovaries after

a short course of gene therapy,

but will the testicles turned ovaries ascend into one's body or stay in the sack? What happens to the penis? When talking about genes, I would assume that the penis would drastically shrink, taking on a clitoris appearance. I wonder if young male pre-puberty kids who display more feminine characteristics could actually reverse their sex? I wonder.

[Hash (imported)]

Controlled by creationists? If you think evolution is actual science then explain complexity & entropy? My problem with evolutionists is that they assert or postulate that after life occurred in the primeval swamp, that these single celled creatures were able to determine their need to see, their need to hear, their need to smell, so they developed these specific organs with their cognitive abilities. If you can explain how single celled amoebic creatures could develop complex organs that would enhance their sensory abilities without any outside intervention, then I'd accept evolution. If I could think and determine through the process of thought what I'd like to have and obtain it or develop it, I might grow myself a bigger penis, I might regrow my testicles and scrotum, I might actually grow two penises. But alas, no one has this ability and no single celled creature was able to think and make the decision as to what it needed and then cognitively make it come to pass. There had to be outside influence and there was. Notice I didn't mention a creator or God. So before you postulate that creationism is impossible or implausible, I'd suggest you study complexity. Humans alone are so complex that evolution pales in light of the unique features of man. Study the Second Law of thermodynamics, or the Law of Increased Entropy (law meaning it's a fact unlike evolution). The Law of Increased Entropy states that matter/energy deteriorates gradually over time. If evolution is true, then the Law of Entropy is wrong, and it isn't. Please educate yourself.