For the first time, scientists have identified the gene responsible for red color in the beaks and feathers of birds.
Many species of birds have distinctive red feathers and beaks and they are not without reason. Birds use their red color as singles to attract mates or to scare off rivals. But how have these birds gained their red color?
Don't Miss: Sam's Club Black Friday 2016 Details
Birds such as zebra finches have a remarkable ability to convert yellow pigments from their diet into bright red, but the mechanism for the process was unclear. For the first time, researchers have identified the gene that allows birds to produce red color.
“To produce red feathers, birds convert yellow dietary pigments known as carotenoids into red pigments and then deposit them in the feathers,” said Miguel Carneiro of Universidade do Porto in Portugal. “Birds also accumulate these same red pigments in one of the cone photoreceptor types in their retina to enhance color vision. We discovered a gene that codes for an enzyme that enables this yellow-to-red conversion in birds.”
For the study, a team of researchers sequenced the DNA of yellow and red canaries as well as red siskins to find out the gene responsible for red color. The genome of red canaries played a vital role in identifying the gene since this variety of bird was developed after crossbreading between yellow canary and red siskins.
Researchers found that over 15,000 genetic variations could be associated with red coloring but an enzyme CYP2J19 within cytochrome P450 really stood out and it was found active in skin and liver. In another separate report, scientists also reached to the same conclusion. They compared the genes of standard zebra finches (which have bright beak) with mutant zebra finches with yellow beaks. They found that three related cytochrome P450 genes were either missing or mutated in the genomes of yellowbeak finches and led them to yellow coloration instead of red.
The identity of the gene not only solved the mystery of red color in birds but it may help find the evolution and ecology of the red coloration in future. Plus, it raises many intriguing questions as well. For instance, the gene belongs to the family of genes known for detoxification.
“In sexual selection, red color is thought to signal individual quality and one way it can do this is if the type or amount of pigmentation is related to other physiological processes, like detoxification,” said co-author Staffan Andersson from University of Gothenburg. “Our results, which link a detoxification gene to caroteniod metabolism, may shed new light on the debated honesty of carotenoid-based signals.”