Scientists Create 12-Headed Jellyfish (gene manipulation alert!)

Yahoo News ^ | August 1, 2007 | Charles Q. Choi

[NYer]

Jellyfish with up to a dozen heads have been created in the laboratory by carefully monkeying with a few genes.

The genetic experiments could shed light on how natural colonies of other multi-headed organisms first originated, including some that build coral reefs.

Researchers targeted so-called Cnox genes, which help control how the bodies of jellyfish are laid out as their embryos develop. These genes are closely related to Hox genes, which play a similar role in humans.

How they did it

They experimented on the European hydromedusa (Eleutheria dichotoma), collected from the south of France. (In Greek mythology, the Hydra was a monster with innumerable heads, while Medusa had writhing snakes for hair.)

The researchers designed RNA molecules that specifically only "silenced" Cnox genes in these saltwater critters. Normally, the saltiness of these animals would prevent the molecules from entering their cells, but the scientists diluted seawater with freshwater enough "where the jellyfish still survived and the RNA got in," said evolutionary biologist and invertebrate zoologist Bernd Schierwater at the Hanover University of Veterinary Medicine in Germany.

By inhibiting one Cnox gene called Cnox-3, two heads often formed, where both were completely functional—regarding food intake, for instance. By deactivating another, Cnox-2, more than two heads usually sprouted—"up to a dozen," Schierwater told LiveScience.

He and colleague Wolfgang Jakob, also at Hanover, detailed their findings in the Aug. 1 issue of the online journal PLoS ONE.

Twelve heads better than one?

Animals with many heads are rare in nature, suggesting that two or more heads usually aren't better than one—having more than one head results in costs with no immediate matching benefits.

However, Schierwater noted that corals, which are animals, often form colonies by adding heads to a common stalk, each of which connect to a common gut, just as with the modified jellyfish that the researchers created.

Jellyfish are related to the creatures that build coral reefs—they are both carnivores belonging to a group called cnidarians, which means "stinging nettles," because of their stingers. Schierwater conjectured the solitary ancestors of corals and other colonial organisms might have adapted genes related to multiple heads long ago "in such a way that animal colonies were able to emerge."

Indeed, these findings suggest the suppression of just a few genes could have led to incredible diversity in body plans "from the very beginning," Schierwater said, shedding light on "the evolution and development of animal life in general."

[Hail Spode]

Fascinating stuff. I am a little perplexed at their contentions on how this sheds light on evolution of animals as the researchers claim. The article says "The researchers designed RNA molecules". Further, the description of the Hox and Cnox gene controls remind one of the check boxes on the tabs of Windows software. Are the scientists saying that the whole system was there "from the beginning"? If so, it is like they have just learned how to change screen savers and using it as evidence that Windows code wrote itself.

[VaRepublican]

I dont know friend, If your making twelve heads now on a “simple genetic creature”, then it would seem we should already be curing cancer with “monkeying around with genes”. I am amazed at how it’s reported like it’s no big deal. Hey by the way gays getting married is normal and if your offended by it, why you are just backwards.

[Enchante]

re: 12-headed jellyfish

We already had this type of creature - it’s called the Senate Judiciary Committee

[ok, maybe that’s more like an 18-headed jellyfish or whatever the exact number of members may be]

[MeanWestTexan]

I see no logical connection with being pleased with scientific progress and being pleased with gays getting married.

Indeed, if having the tendancy to have a homosexual perversion is genetic, as gays claim, this sort of experimentation would be the kind progress that would lead to a cure of homosexuals.

[ZULU]

The PERFECT politician!!!

[joebuck]

Does it also have 10 horns and 7 crowns?

[NYer]

I give up ... what is that?

[NYer]

Question ... does having more heads result in more stingers?

[Calpernia]

This article said they shut down a gene to stimulate the other gene to grow. But they didn’t say which gene. Maybe it was the one for the stingers?

http://www.world-science.net/othernews/070801_hydra.htm

[twonie]

Yes, sir, when God said we didn’t have the heads for the tree of the knowledge of good and evil, He was, as usual, right. We have not the brain power to know when to stop or in which direction to go. And this one is he ultimate proof.

[VaRepublican]

man your a pro!

[Mad Dawg]

My reply was going to be WHY?

Democrats want to increase their congressional candidate pool.

[Dr._Joseph_Warren]

However, Schierwater noted that corals, which are animals, often form colonies by adding heads to a common stalk, each of which connect to a common gut, just as with the modified jellyfish that the researchers created.

Are these really added 'heads' or are they just added 'mouths'.

Big difference.

[JasonC]

They've found the code that regulates body plans. Been known for a little while, but the variety already present this early is relatively recent. Was an article about it in Nature (or Science) recently, made the cover. The big deal is that these critters predate the Cambrian explosion by about 100 million years. Meaning all the code for body type variety was there before that took off (nearly all existing body plans appear for the first time in the Cambrian explosion, in a relatively short space of time). We are getting close to understanding what actually happened then, and really led to most of the variety of life seen on earth. At a mechanism level, not a general hand waving principle.