Las tropical butterflies Heliconius They are known for the brightly colored patterns on their wings. These striking color patterns not only deter predators (butterflies are poisonous and unpleasant to birds), but are also important signals during partner selection.
A team led by evolutionary biologist Richard Merrill from LMU Munich, in collaboration with researchers from the Universidad del Rosario in Bogotá (Colombia) and the Smithsonian Tropical Research Institute (Panama), has taken advantage of the diversity of warning patterns of different species Heliconius to investigate the genetic basis of these preferences. In doing so, the scientists identified a gene directly linked to evolutionary changes in visually guided behavior; It is the first time that such a link has been demonstrated in an animal, as reported in the Scientific magazine.
For their research, the researchers conducted hundreds of behavioral experiments investigate the mating preferences of three Heliconius species in Colombia: Heliconius melpomene j Heliconius shirtboth with a bright red band on their forewings, and Heliconius cydno, which has a white band. previous band. They found that males of all three species prefer partners who look like them.without differences in the preferences of the two furthest red species.
Using genomic analysis, the researchers showed that the preference for red females is linked to a genomic region where hybridization between these two red species has resulted in the exchange of genetic material. “We have been able to identify regucalcin1 as a key gene that regulates visual preference butterflies«says Matteo Rossi, who researched the butterflies in Merrill’s laboratory together with fellow PhD student Alexander Hausmann. “When regucalcin1 is silenced, courtship with females of the same species is affected, demonstrating a direct link between the gene and behavior,” Rossi explains.
How Tropical Heliconius Butterflies Choose Their Mates
Additional analyzes by the scientists showed that regucalcin1 was transferred from H. melpomene to H. timareta at some point in its evolutionary past. “We have known for some time that the gene for the red color pattern was introduced from one species to another by hybridization, and we suspect that the same could be true for the corresponding preference.
It is really exciting to finally show it and identify the specific gene,” says Carolina Pardo-Díaz, dean of biology at the Universidad del Rosario and one of the lead authors of the paper. Thanks to regucalcin1, the attractiveness of red females increased and thus the reproductive success of H. timareta.
“We see differences in visual preferences around us in nature as animals choose who to interact with.” couple. Our results allowed us, for the first time, to establish a direct link between a particular visual preference and a specific gene, and also to demonstrate that hybridization may play an important role in the evolution of this behavior,” Merrill emphasizes.