CHARACTERIZING THE OPTIX NETWORK IN HELICONIUS BUTTERFLY WING COLOR PATTERNING

Abstract

Heliconius butterflies are an incredibly diverse species, with many displaying bold red, black and yellow coloring. Interestingly, a single gene, optix, has been shown to be responsible for the red coloring of these as well as many other butterflies within the Lepidoptera order. Optix is a highly conserved transcription factor with ancestral function in Drosophila eye development, so how has this gene evolved its function in butterfly wing pigmentation? Here, I describe work I did to elucidate both the upstream and downstream actors of the Optix network in the Heliconius wing pigmentation pathway in an effort to provide insight into how this novel function of optix has evolved. First, I explore the role of optix regulatory elements in wing color patterning using the CRISPR/Cas9 system to delete candidate optix cis-regulatory elements. I then investigate the conservation of the ancestral Optix eye network in the pigmentation pathway by deleting candidate downstream target genes of Optix and describe the resulting wing pattern mutations. This work provides foundational information on the role of this network in Heliconius wing color patterning and how it may have evolved.