Publication
Evolution of compound eye morphology underlies differences in vision between closely relatedDrosophilaspecies
Publisher:
Cold Spring Harbor Laboratory
Date:
16-07-2023
DOI:
10.1101/2023.07.16.549164
Abstract: Insects have evolved complex visual systems and display an astonishing range of adaptations for erse ecological niches. Differences in eye size within and between Drosophila species provide the opportunity to study the impact of eye structure on vision. Here we further explored differences in D. mauritiana and its sibling species D. simulans and confirmed that D. mauritiana have rapidly evolved larger eyes as a result of more and wider ommatidia than D. simulans since their recent common ancestor. The functional impact of eye size, and specifically ommatidia size, is often only estimated based on the rigid surface morphology of the compound eye. Therefore, we used 3D synchrotron radiation tomography to measure optical parameters in 3D, predict optical capacity, and compare the modelled vision to in vivo optomotor responses. Our optical models predicted higher contrast sensitivity for D. mauritiana , which we verified by presenting sinusoidal gratings to tethered flies in a flight arena. Similarly, we confirmed the higher spatial acuity predicted for Drosophila simulans with smaller ommatidia and found evidence for higher temporal resolution.