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Updated: May 14, 2026
06:19
In situ Protocol for Butterfly Pupal Wings Using Riboprobes
Published on: May 28, 2007
araucan regulates butterfly wing iridescence by coordinating scale structure and pigmentation
Martik Chatterjee1,2,3, Cedric Finet4, Kate J Siegel1,2
1Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.
Proceedings. Biological Sciences
|May 12, 2026
Summary
The transcription factor gene araucan regulates butterfly wing color by altering scale structure and pigmentation. Loss of araucan function shifts wing iridescence and affects eyespot coloration in Junonia coenia.
Area of Science:
- Developmental biology
- Evolutionary biology
- Genetics
Background:
- Butterfly wing coloration arises from complex interactions between structural and pigmentary elements.
- The genetic underpinnings of structural iridescence and its coordination with pigmentation are largely unknown.
- Understanding gene regulation of color is crucial for explaining the evolution of diverse wing patterns.
Purpose of the Study:
- To investigate the role of the Iroquois-complex transcription factor gene araucan in butterfly wing color.
- To determine how araucan influences both structural iridescence and pigmentary coloration.
- To link gene regulation to the evolution of spatially coordinated color components.
Main Methods:
- Utilized CRISPR-Cas9 gene editing to create araucan knockouts in Junonia coenia.
- Analyzed changes in wing scale morphology, specifically lower lamina thickness (LL).
- Quantified alterations in iridescence and pigment density in dorsal and eyespot scales.
Main Results:
- Loss of araucan function induced a shift from golden-brown to blue iridescence in dorsal wing scales.
- Eyespot center scales changed from purple-violet to dull grey-brown upon araucan knockout.
- Phenotypic changes correlated with altered lower lamina thickness and reduced eyespot ground scale pigmentation.
Conclusions:
- The transcription factor araucan is a key regulator of butterfly wing color, controlling both photonic structures and pigmentation.
- araucan acts in a pattern-specific manner to modulate color in different wing regions.
- These findings establish a framework for understanding how gene regulation drives the evolution of complex color patterns.
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