Meeting Abstract
Animal coloration is an attractive model for studying how conserved developmental toolkit genes influence the form and function of traits. Butterfly wing patterns provide an ideal system for studying how highly conserved developmental genes are responsible for generating a vast array of natural variation. Recently, it was shown that genes in the melanin pathway modulated both scale color and morphology. Here we examine if a gene, WntA, which is responsible for pre-patterning of melanic pigment coloration in Heliconius butterflies, also controls cyto-structural variation in wing scales. Knockouts of WntA across several Heliconius species generated the expected pigment changes, with wing regions typically colored black, instead developing red scales. Here, we show that WntA knockouts also had changes in scale structures. The mutant scales were structurally intermediate between wild type black and red scales: the scale ultrastructures (width, length, and area) were similar to black wild type scales, but the nanostructures (lamella ridge and crossrib distance) were more similar to wild type red scales. Our results suggests that WntA is not only responsible for pre-patterning scale pigmentation, but also involved in patterning of scale nanostructures.
