Genome complexity: How butterfly wings are made (Introduction)

by David Turell , Saturday, October 22, 2022, 17:27 (553 days ago) @ David Turell

Ancient non-coding DNA regulates genes:

https://www.sciencedaily.com/releases/2022/10/221021145842.htm

"Butterfly wing patterns have a basic plan to them, which is manipulated by non-coding regulatory DNA to create the diversity of wings seen in different species, according to new research.

"The study, "Deep cis-regulatory homology of the butterfly wing pattern ground plan," published as the cover story in the Oct. 21 issue of Science, explains how DNA that sits between genes -- called 'junk' DNA or non-coding regulatory DNA -- accommodates a basic plan conserved over tens to hundreds of millions of years while at the same time allowing wing patterns to evolve extremely quickly.

"The research supports the idea that an ancient color pattern ground plan is already encoded in the genome and that non-coding regulatory DNA works like switches to turn up some patterns and turn down others.

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"/We see that there's a very conserved group of switches [non-coding DNA] that are working in different positions and are activated and driving the gene," Mazo-Vargas said.

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"This study focused on the effect of non-coding DNA on the WntA gene. Specifically, the researchers ran experiments on 46 of these non-coding elements in five species of nymphalid butterflies, which is the largest family of butterflies.

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"The researchers found that across four of the species -- Junonia coenia (buckeye), Vanessa cardui (painted lady), Heliconius himera and Agraulis vanillae (gulf fritillary) -- each of these non-coding elements had similar functions with respect to the WntA gene, proving they were ancient and conserved, likely originating in a distant common ancestor.

"They also found that D. plexippus (monarch) used different regulatory elements from the other four species to control its WntA gene, perhaps because it lost some of its genetic information over its history and had to reinvent its own regulatory system to develop its unique color patterns.

"'We have progressively come to understand that most evolution occurs because of mutations in these non-coding regions," Reed said."

Comment: repeating the same successful plan over and over makes perfect sense. Reed's comment is right on point. To make a new species genes must be re-regulated to produce a new form.