RSI Research Seminar

Join us every other Monday at noon for lunch and a 30-minute research talk, presented by Resnick Sustainability Institute Graduate Fellows and Caltech researchers funded by the Resnick Sustainability Institute. To see the full schedule of speakers, visit the RSI Research Seminar web page. Seminars currently take place in a hybrid format, both in-person (Jorgensen building first-floor conference room) and via Zoom. For more information and to get the Zoom login info, please reach out to ramonae@caltech.edu

Neural Mechanisms of Odor-Guided Foraging in Alternative Pollinators

The global collapse of bee populations threatens both natural ecosystems and human food security, creating an urgent need to diversify pollinator populations. Calliphoridae, or blowflies, are perhaps best known for their role in decomposing animal remains. Less appreciated is that blowflies of both sexes utilize pollen and nectar as important food sources, with males particularly reliant on nectar as a source of carbohydrate to fuel flight. Although bees carry the largest pollen-load relative to other taxa, the abundance and robustness of flies may enable them to be equally effective pollinators. Understanding the olfactory biology of these species can enable the design and mass release of genetically-engineered "male-only" strains as single-generation targeted and managed pollinators. To investigate this possibility, we focused on the Australian sheep blowfly, Lucilia cuprina, which has a fully sequenced genome. We characterize the morphology of the antenna, using high-resolution electron microscopy to identify the distribution of olfactory sensillar types and their relative arrangements. Our in-situ hybridization experiments reveal the distribution of different receptors within the olfactory receptor neurons (ORNs) along the antennae. We find that, unlike the commonly studied fruit fly, individual ORNs in Lucilia cuprina express a combination of co-receptor systems. In the central brain, we characterize the convergence domain of these ORNs, the antennal lobe. We identify ~50 glomeruli in the antennal lobe, about the same as that of the much smaller fruit fly. These genetic, transcriptomic, and neuroanatomical observations suggest different olfactory processing strategies across dipteran species. We are working towards generating transgenic blowflies to investigate the functional properties of the olfactory system and developing behavioral experiments to determine olfactory sensitivity and preferences.