PT  - JOURNAL ARTICLE
AU  - Nathan P. Buerkle
AU  - Nicholas W. VanKuren
AU  - Erica L. Westerman
AU  - Marcus R. Kronforst
AU  - Stephanie E. Palmer
TI  - Sex-limited diversification of the eye in <em>Heliconius</em> butterflies
AID  - 10.1101/2022.04.25.489414
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.04.25.489414
4099  - http://biorxiv.org/content/early/2022/04/26/2022.04.25.489414.short
4100  - http://biorxiv.org/content/early/2022/04/26/2022.04.25.489414.full
AB  - Butterflies have evolved an immense diversity in eye organization to support a range of vision-based behaviors including courtship, oviposition, and foraging. This diversity has been surveyed extensively across the butterfly phylogeny, and here we take a complementary approach to characterize the eye within a group of closely related Heliconius butterflies. Using a combination of immunostaining for different opsins and eyeshine for determining the distribution of light-filtering screening pigments, we identified several sexually dimorphic features of eye organization where male eyes varied and female eyes did not. Ultraviolet (UV) sensitive photoreceptors varied in which of two UV opsins were expressed, including co-expression of both within single photoreceptors, and these differences were consistent with a role in courtship and conspecific identification. Additional differences across species and sex included the distribution of three ommatidial types defined by the expression pattern of UV and blue opsins, the distribution of a red screening pigment, and which ommatidial types expressed the red screening pigment. We hypothesize that female eyes are optimized for a dimorphic behavior such as oviposition, while male eyes adapt to other selective pressures such as the local light environment.Competing Interest StatementThe authors have declared no competing interest.