AUTHOR=Fenner Jennifer , Benson Caleb , Rodriguez-Caro Luis , Ren Anna , Papa Riccardo , Martin Arnaud , Hoffmann Federico , Range Ryan , Counterman Brian A. 

TITLE=Wnt Genes in Wing Pattern Development of Coliadinae Butterflies

JOURNAL=Frontiers in Ecology and Evolution

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2020.00197

DOI=10.3389/fevo.2020.00197

ISSN=2296-701X

ABSTRACT=<p><italic>Wnt</italic> genes are major developmental genes highly conserved across all animals. Yet, our understanding of the <italic>Wnt</italic> gene repertoire and their functions is still largely incomplete. In Lepidoptera, Wnt genes have been implicated in wing pattern development. For example, <italic>WntA</italic> has been shown as a driver of wing pattern diversification in nymphalid butterflies. In this study, we characterize the <italic>Wnt</italic> gene repertoire in <italic>Zerene cesonia</italic> (Family: Pieridae), which diverged from nymphalids ∼51 million years ago, to determine if <italic>Wnt</italic> genes may have a conserved role in wing development across distant butterfly lineages. We first show that <italic>Wnt</italic> gene content is highly conserved across butterflies, but that there is strikingly different expression across the eight <italic>Wnt</italic> genes during wing development of <italic>Z. cesonia</italic> and nymphalid butterflies. Surprisingly, while four <italic>Wnt</italic> genes (<italic>Wnt1</italic>, <italic>6</italic>, <italic>7</italic>, and <italic>11</italic>) are expressed during wing development in <italic>Z. cesonia</italic>, the renown nymphalid wing patterning gene <italic>WntA</italic> was undetected. However, despite the differences in <italic>Wnt</italic> gene expression, Heparin injections yielded a similar disruption in wing color pattern development in both <italic>Z. cesonia</italic> and nymphalid butterflies. Interestingly, these assays also resulted in the loss of structurally based ultraviolet (UV) wing patterns in <italic>Z. cesonia</italic>. Collectively, the study shows that pierids maintained the highly conserved nature of <italic>Wnt</italic> gene content in Lepidoptera, but might deploy these genes very differently from nymphalid butterflies during wing pattern development.</p>