Butterflies are colourful and recognition of specific wing colour pattern is likely use as a (1) species recognition and (2) mating cue. The evolution of wing colour pattern likely trigger the evolution of colour vision. In this project we are trying to investigate how duplication events in the eye photopigments (opsins) could tune the ability for butterflies to discriminate location and sex of closely related mimic species (Ledamoisel et al., 2026).
Phylogeny of Morpho butterflies genus (from Chazot et al., 2016) splitted in 2 group: a clade of canopy species (blue line) and a group of understory species (green line). Dimorphism between male (internal pictures) and females (external picture) is variable but often implies differences in blue coloration.
Chazot, N., Panara, S., Zilbermann, N., Blandin, P., Le Poul, Y., Cornette, R., et al. (2016) Morpho morphometrics: Shared ancestry and selection drive the evolution of wing size and shape in Morpho butterflies: MORPHO MORPHOMETRICS. Evolution, 70, 181–194.
References
2026
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Coordinated evolution of opsin genes in iridescent blue butterfly species diversified within tropical forest habitats
Joséphine Ledamoisel, Andrew Dang, Julien Devilliers, Tiphaine Marvillet, Sophie Lemoine, André Victor Lucci Freitas, Carolina Pardo-Diaz, Erika Páez, Manuela Lopez-Villavicencio, Adriana Briscoe, Vincent Debat, and Violaine Llaurens
bioRxiv, Oct 2026
How do adaptive processes acting on the coevolution of opsin genes shape the evolution of colour vision in animals? At large phylogenetic scales, natural selection due to the contrasted light environments has been found to impact the evolution of photoreceptor genes. However, in closely-related species, species interactions due to sexual selection or competition may also influence opsin evolution. Here, we investigate the diversification of opsin sequences and their expression in closely-related blue Morpho butterfly species, living in different vertical strata within tropical forests, to shed light on the biotic and abiotic selective pressures shaping the coordinated evolution of opsin genes. We combined comparative genomics, transcriptomics, and immunochemistry to characterize the expression and the spatial distribution of the opsin proteins found in the eyes of Morpho helenor. We detected a double duplication of the LW opsin and found unique ommatidial types compared to other butterfly species. We then investigated the evolution of opsin genes among 21 Morpho species, found signatures of positive selection on two opsin genes (LW3Rh and BRh), and identified key co-evolving amino-acids within and among these two opsin genes. We showed that such opsin evolution was correlated with both light environment and wing coloration, highlighting the joint effect of several selective pressures in the coordinated evolution of proteins.Competing Interest StatementThe authors have declared no competing interest.European Union (ERC-2022-COG - OUTOFTHEBLUE - 101088089)Human Frontier Science Program
