A team of University of Massachusetts Amherst researchers says it is making progress toward understanding how novel traits develop.
By studying the elongated snout of an African cichlid fish that he found fascinating, associate biology professor Craig Albertson and his team of researchers discovered that these types of strange traits can arise from existing genetic pathways.
“There’s this really bizarre trait in these fish — it’s basically just a big schnoz,” Albertson said. “It makes the fish look really goofy. We indulged ourselves and we said, we just want to know what this thing is and where it comes from developmentally.”
The findings, published in Proceedings of the National Academy of Sciences on Monday, reveal that other species of cichlids could develop the same “schnoz” if existing genetic pathways were recruited.
“My student took little tiny beads and coated them in a protein normally involved in ligament development and planted them in fish that normally don’t have snouts,” Albertson said. “She got these fish to grow snouts just by introducing this molecule into the front of the face — that was super cool.”
The ligament molecule was introduced to the existing genetic pathway in a different species of cichlid that did not have the snout, Albertson said. It intertwined with existing tissues and formed the elongated snout.
The fish’s snout is used to eat algae by sucking it from rocks, and has given it a large evolutionary advantage to other similar species in its African pond habitats, Albertson said.
He called this a “Mr. Potato Head” theory of development — the idea that you can move molecules around to create traits, rather than introducing new genes to the mix.
“In other words, it’s a pre-existing molecular tool kit that’s redeployed,” Albertson said.
To build on the research, Albertson said, he hopes to continue to study novel traits in other species.
“It provides support so now, when we would go looking for or investigating other novelties, we might go in as a default [looking for] a pre-existing developmental module that’s been deployed in another way, in another place,” he said. “I think this work is contributing to a growing body of literature that suggests novelties don’t necessarily need new genes.”Laney Ruckstuhl can be reached at firstname.lastname@example.org. Follow her on Twitter @laneyruckstuhl.