Aphid's Color Comes From a Fungus Gene 132
Iron Nose writes with an account from Byte Size Biology of horizontal gene transfer from a fungus to an insect. The author suspects that we will see lots more of this as we sequence more genomes. "The pea aphid is known for having two different colors, green and red, but until now it was not clear how the aphids got their color. Aphids feed on sap, and sap does not contain carotenoids, a common pigment synthesized by plants, fungi, and microbes, but not by animals. Carotenoids in the diet gives many animals, from insects to flamingos, their exterior color after they ingest it, but aphids do not seem to eat carotenoid-containing food. Nancy Moran and Tyler Jarvik from the University of Arizona looked at the recently sequenced genome of the pea aphid. They were surprised to find genes for synthesizing carotenoids; this is the first time carotenoid synthesizing genes have been found in animals. When the researchers looked for the most similar genes to the aphid carotenoid synthesizing genes, they found that they came from fungi, which means they somehow jumped between fungi and aphids, in a process known as horizontal gene transfer."
Betsey Dexter Dyer on color (Score:5, Interesting)
According to this hottie (see link) black and brown are natural colors produced by pigments; usually red, oranges and yellows are the carotenoids which animals get from foods, and blues and greens (in birds) come from microstructure rather than actual color. (Obviously a green caterpillar gets the color from the diet. A bit different for animals, since I've never seen a green cow.)
http://www.learnoutloud.com/Catalog/Science/Biology/Basics-of-Genetics/31316 [learnoutloud.com]
She also says that horizontal gene transfer is very common, and that 90% of our DNA is viral. The viruses we hear about are the ones that make us sick. The ones that have no ill effects we don't notice so much; these are also called viruses or jumping genes.
http://wheatoncollege.edu/quarterly/q2003fall/bacteria.html [wheatoncollege.edu]
Re:Betsey Dexter Dyer on color (Score:5, Interesting)
90% of our DNA is viral. The viruses we hear about are the ones that make us sick. The ones that have no ill effects we don't notice so much; these are also called viruses or jumping genes
This is why I wonder about sexual behaviour which doesn't lead to reproduction. Could our genes have found ways to propagate themselves without reproduction?
Re:Nature's own GMO (Score:3, Interesting)
AMEN. As one planning on going into this area, I think about genetic engineering a lot, and that was the first thing that came to my mind too. I love how the anti-GE guys out there rail against the 'dangers' of foreign DNA being inserted into plants yet are blissfully unaware that species get foreign DNA all the time. Humans are 3-8% viral DNA depending on who you ask, and we're more genetically similar to chimps than two unrelated types of corn are to each other. My worry is that, in typical crank fashion, they'll take something like this and say 'See, we were right, inserted genes can jump to other plants, nya, nya, nya!' and totally miss the fact that it could happen with anything, especially in plants. But this won't stop them from parading their ignorance any more than facts stopped anti-vacationists or any other denialist group. They're right, and damn it, any science that proves them wrong, no matter how overwhelming, is clearly part of a plot by Monsanto to make them sick (cause killing your customers is a great business model), and therefore it to be dismissed or misused. A few million years of accumulated random mutations and horizontal gene transfer and a little human selection is fine and dandy, but add one gene in a controlled setting in a precise manner, and suddenly you've gone too far and no amount of testing well catch any problems all because scientists are either arrogant ebil B-movie villains or unethical, bribed off conspirators. Riiiiight.