Researchers Identify Gene That Gives Colombian Dart Frogs Their Black Coloration
November 10, 2017
The Colombian dart frog sports a single gene named MC1R that gives the frog the black pigment that, combined with their red, yellow, and orange colors, sends a signal to predators that “hey, I’m poisonous.”
Post-doctoral researcher Andrés Posso-Terranova and University of Saskatchewan biology professor, José Andrés, determined that the disruption of the gene is what gives the frogs the black stripes and blobs present on their skin. Their paper detailing the gene was published in the journal Evolution.
“We knew the same gene stimulates the production of black pigment in other animals, but it’s also responsible for camouflage in mice and red hair in humans,” José Andrés told the Star Phoenix. “There was no evidence of a correlation with coloration of frogs until now.”
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Posso-Terranova and Andrés photographed more than 300 poison dart frogs in the jungles of Colombia's Chocó province, and classified and collected DNA from more than 90 individual frogs. At the university, they used DNA technology to screen more than 15,000 genes that could be associated with how the frogs acquire their coloration.
During the course of their study, they found that unrelated frog species from the north and south of Chocó province have mutations of the MC1R gene in the same DNA region. This, the researchers say, explains why frogs share similar black coloration and patterns even though they are not closely related, and live hundreds of kilometers apart.
“These mutations associated with black color show the footprints of natural selection,” Andrés said. “It confirms that dark patterns are beneficial for frogs’ survival, so it has been passed down through generations.”
The study was funded by Canada’s Natural Sciences and Engineering Research Council and a grant from the Colombian government.