Presentation Details
| Population-Level Variation in Olfactory Receptor Tuning in Drosophila mojavensis Dilini Karunappuli Herath Mudiyanselage, John E.Layne, Stephanie M.Rollmann. University of Cincinnati, Cincinnati, OH, USA |
Abstract
Host plant associated divergence is a major driver of ecological speciation. In herbivorous insects, adaptation to distinct plant hosts can shift insect behavioral preference and sensitivity of the peripheral olfactory nervous system to plant chemical cues. These cues are detected by olfactory sensory neurons (OSNs) expressing odorant receptor genes. Drosophila mojavensis is a powerful insect system for studying incipient speciation, because its four geographically isolated populations each specialize on a chemically distinct cactus host. Here, we examine how OSN tuning differs between two of these populations, Catalina and Mojave. Using single sensillum recordings, we quantified OSN responses across 10 antennal sensilla to 39 cactus-associated odorants across an eight-point concentration gradient. This generated a high-resolution dataset capturing the magnitudes of population specific responses. Results revealed that while many OSNs show conserved tuning, a subset display significant divergence to multiple odorants and concentrations. For a subset of odorant-OSN combinations, Mojave population exhibits an increased sensitivity to cactus- associated odorants at intermediate concentrations (10-5 -10-3) consistent with horizontal shifts in tuning curves. The observed population-specific shifts in OSN dose-response curves highlight divergence in peripheral olfactory coding between the two populations. These results provide a framework for identifying OSNs that show population specific differences in tuning that are likely contributors to odor-guided behavioral differences in D. mojavensis.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
Content Locked. Log into a registered attendee account to access this presentation.