- Author: Kathy Keatley Garvey
Amber Crowley-Gall of the UC Davis Department of Entomology and Nematology will be among the rising stars featured in an international symposium on “The Frontiers in Chemical Ecology,” part of the Aug. 8-12 joint meeting of the International Society of Chemical Ecology (ISCE) and the Asia-Pacific Association of Chemical Ecologists (APACE) in Kuala Lumpur, Malaysia.
Crowley-Gall, a two-year USDA-NIFA (U.S. Department of Agriculture/National Institute of Food and Agriculture) postdoctoral fellow in the laboratory of associate professor and community ecologist Rachel Vannette, will present "Olfactory Variation Among Closely Related Cactophilic Drosophila Species," a collaborative project with her doctoral dissertation advisor, Professor Stephanie Rollmann of the University of Cincinnati.
“I am very excited about the opportunity to participate in this symposium,” said Crowley-Gall, who holds a doctorate in biological sciences from the University of Cincinnati (2019), and a bachelor's degree in biological sciences, magna cum laude, from Wright State University (2012).
UC Davis distinguished professor Walter Leal of the Department of Molecular and Cellular Biology and a former chair of the UC Davis Department of Entomology, is organizing and producing the hybrid (in-person and virtual) symposium.
Others to be spotlighted in the Frontiers symposium: postdoctoral fellows Rick Fandino of Cornell University and Ani Agnihotri of Murdoch University; soon-to-be-assistant professor Dan Peach of the University of Georgia; associate professors Mengbo Guo of the Chinese Academy of Agricultural Sciences, Zain Syed of the University of Kentucky (formerly of the Walter Leal lab, UC Davis) and Karen Menuz of the University of Connecticut; and professor Chen-Zhu Wang, of the Chinese Academy Sciences.
"I am grateful for this opportunity to present my research and network with other chemical ecologists around the world," said postdoctoral scholar Rick Fandino, a research associate at Cornell University's Department of Ecology and Evolution. "As a first-generation U.S. American Latinx these opportunities are critical to advance in highly competitive and underrepresented STEM fields."
“It's incredibly supportive of Walter to use his standing in the field to help elevate early career researchers," said selected participant Greg Pask, an assistant professor of biology, Middlebury College, Vermont. "And I'm excited to hear about the exciting research from this generation of chemical ecologists.” (For more on the invited speakers, access this short video at https://youtu.be/liy9HpKTmOo)
The ISCE-APACE joint meeting, themed “Managing Sustainability in Challenging Times,” will include 15 plenary, 15 symposia, as well as invited lectures. Among the lectures is the inaugural Wittko Francke Daaks-Chemicals Memorial Lecture, sponsored by Wittko Francke's Daaks-Chemicals Fund. ISCE promotes the understanding of interactions between organisms and their environment that are mediated by naturally occurring chemicals.
First In-Depth Analysis. Crowley-Gall's research on Drosophila repleta is "the first in-depth analysis of the olfactory system across the repleta group and provides the opportunity to test for conserved mechanisms in the olfactory system underlying divergence and host shift." A species of vinegar fly in the family Drosophilidae, D. repleta is a carrier of foodborne illnesses.
"Chemical cues are important for a wide range of tasks such as host plant identification and localization, oviposition site selection, and mate recognition," she explains in the abstract of the paper, co-authored by Stephanie Rollmann, John Layne, Aaron Hamrick, Lucinda Lawson, all of the Department of Biological Sciences, University of Cincinnnati. "Insects use volatile cues emitted from plants when navigating toward an appropriate host and divergence in odor detection has been shown to result in shifts in host use between populations and in some cases reproductive isolation between populations and eventual speciation. A comparative phylogenetic approach can determine whether variation in the olfactory system is linked to shifts in host plant use and is a means to determine the influence of olfactory tuning on divergence between species.
"A useful model to examine this is the Drosophila repleta species group, a radiation of flies specializing on cacti, that exhibits three types of host use: 1) Opuntia specialists, 2) columnar specialists, and 3) “generalists” on both. Opuntia, a flat leaf cactus, is hypothesized to be the ancestral host, and the use of the more chemically complex columnar cactus is believed to be an acquired trait. Columnar cacti contain elevated levels of secondary compounds that can be toxic to flies and affect the volatile headspace flies are exposed to when choosing a suitable host plant. This study examined the extent to which odor tuning has diverged along with the repeated shifts in host plants within the Drosophila repleta species group. We characterized odor response profiles from select sensillar subtypes across multiple species within the repletagroup as well as the outgroup D. melanogaster. Variation in both sensitivity and specificity to odors was observed, with some ORNs exhibiting variation associated with host cactus use. This study is the first in-depth analysis of the olfactory system across the repleta group and provides the opportunity to test for conserved mechanisms in the olfactory system underlying divergence and host shift."
Bedoukian Research, Inc. will sponsor the Frontiers in Chemical Ecology symposium. The public can sign up for the free-accesswebinar here: https://bit.ly/3PeXJhu.