TORONTO — Using genetic manipulation, U.S. scientists altered the brains of nematode worms, causing them to become attracted to wrigglers of the same sex.

While the scientists can’t say what this means for sexual orientation in humans, it does raise the possibility that sexual preference is wired in an organism’s brain.

Biologist Erik Jorgensen and his research team at the University of Utah took female nematodes with normal reproductive organs and activated genes that determine "maleness," thereby converting female brains to male brains.

"So we did that and now the females are attracted to other females," Jorgensen said from Salt Lake City. "That told us that the brain was sufficient for all of the sex-specific behaviours, for sexual attraction."

In other words, co-author Jamie White, a postdoctoral researcher in Jorgensen’s lab, said in a statement: "They look like girls, but act and think like boys. The (same-sex behaviour) is part of the nervous system."

Nematodes, or C. elegans, are millimetre-long worms that live in soil and eat bacteria. Many of the genes found in nematodes are also found in other animals — including people — making them a good model for human research.

Because the worms have no eyes, sexual attraction is based only on their sense of smell. Male nematodes are drawn to sex-attractant odours, called pheromones, produced by the females.

The researchers, whose work is published in the most recent issue of Current Biology, first tested pheromones on male nematodes.

"We put a spot of that beautiful odour on a plate and we put the males down on the plate," said Jorgensen. "They went straight . . . for the source of that pheromone."

"And when we make these transgendered females, they do the same thing. As soon as she detects that there are other females on the plate from the odours, she zips right up there," he said. "Normally a female would avoid that spot. They actually have an active repulsion."

But scientists found there is more to the mating ritual than just sexual attraction.

"The females that are now attracted to other females, they get there and they don’t know what to do," said Jorgensen, pointing out that there are other brain cells involved in the actual mechanics of sex.

Under certain adverse conditions — what Jorgensen calls "life on the prairie . . . when there are no boys around" — female nematodes can become hermaphrodites, producing both sperm and eggs to ensure propagation. Those used in this experiment were "absolutely female," he said.

Still, Jorgensen said he’s reluctant to make strong inferences about human behaviour from studies of worms.

"Our brains are very complex. And because our brains are so large, an emergent property has arisen, which is consciousness and will. We can make choices. So to say that personal choice or free will doesn’t play a role in human sexuality is a simplification."


Source: TheChronicleHerald.ca

lol... wtf

aww ghey

Eh...

lol - already posted - twice (first 2 threads were merged)
Was posted elsewhere a few days ago. then BPN earlier, and now again.

http://www.neowin.net/forum/index.php?show...597246&st=0

http://www.neowin.net/forum/index.php?showtopic=597246
There's already been two threads about this.
EDIT: WelshBluebird beat me to it!

ewww wtf

it was known for a long time that certain lower life forms had pheremones. the most interesting part of the study is "The females that are now attracted to other females, they get there and they don’t know what to do". So it has nothing to do with actual sex, but attraction. Got it.

The problem is when you have politics behind this, people won't report this as the most interesting part of the story. We also know humans don't operate on pheremones.

Sorry, but this is already posted

http://www.neowin.net/forum/index.php?showtopic=597246

[Thread Closed]