Aphid's Color Comes From a Fungus Gene

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."

Comments

Re:wiki

[mrmeval]

They state with authority the gene came from a fungi but they have not shown where they have observed this happening. The fact that the genes are identical does not mean they're of the same origin.

Correlation fallacy, much?

[Rogerborg]

From the source paper:

Phylogenetic analyses show that these aphid genes are derived from fungal genes, which have been integrated into the genome and duplicated.

Until you observe the process happening, all you've got is correlation. Even if it is gene transfer, how do you know the transfer wasn't the other direction? I call XKCD on that.

Re:fungi

[Cassius Corodes]

To completely blow your mind - did you know we have virus DNA in our DNA? Some of which has even been adapted for our internal use.