The National Science Foundation follows researchers taking a second look at “junk” DNA – the genes that don’t seem to do anything and instead just sit in a genome like leftovers in a fridge. Apparently, this “noncoding regulatory DNA” controls how the basic, shared, off-the-rack butterfly wing-pattern expresses itself in hundreds of intricately different ways across different butterfly species:
The research supports the idea that an ancient color pattern ground plan is already encoded in the genome, and that noncoding regulatory DNA works like switches to turn up some patterns and turn down others.
“We are interested to know how the same gene can build these very different-looking butterflies,” said Anyi Mazo-Vargas of George Washington University, the study’s first author. The senior author, Robert Reed, is at Cornell University.
“We see that there’s a group of switches [noncoding DNA] that are working in different positions and are activated and driving the gene,” Mazo-Vargas said.
Previous work in Reed’s lab uncovered key color pattern genes: one (WntA) that controls stripes and another (Optix) that controls color and iridescence in butterfly wings. When the researchers disabled the Optix gene, the wings appeared black, and when the WntA gene was deleted, stripe patterns disappeared.
This study focused on the effect of noncoding DNA on the WntA gene, specifically, on 46 of these noncoding elements in five species of nymphalid butterflies, the largest family of butterflies.
You can read more of the butterfly research here, in Science.