october, 2017

10oct1:00 pm2:00 pmTranscriptome variation underlying life history divergence and reproductive isolationProfessor Bill Etges


Event Details



Adaptation to different environments has long been argued as a potential cause for reproductive isolation between populations experiencing low or variable amounts of gene flow. Evidence from multiple study systems has suggested that premating isolating mechanisms often evolve early as populations diverge, with postmating isolation evolving later. We have focused on regionally isolated desert populations of cactophilic Drosophila mojavensis that exhibit low levels of sexual isolation, where use of different host cacti has resulted in genetically divergent life histories. Multiple experiments have revealed egg to adult development time, a key life history trait, is genetically correlated with premating isolation mediated by courtship song and epicuticular hydrocarbon differences.

We have employed both microarray analysis and transcriptome sequencing to assess transcriptional variation across the life cycle and gene expression differences caused by host plant use, temperature variation, desiccation regimes, mating status, as well as ubiquitous factor interactions.  Transcriptional variation over the entire life cycle revealed changing patterns of gene expression with stage and age revealing functional gene clusters associated with age-specific reproduction and the onset of senescence.  Adults differing in egg to adult development times showed significant expression differences in hundreds of genes that may explain why adult sexual behaviors are determined by preadult experience.  Annotation of these gene clusters has provided insights into functional genetic mechanisms for how adaptation to different environments has resulted in differences in mate choice behaviors and sexual isolation between populations.

Bill Etges is a Professor in the Department of Biological Sciences at the University of Arkansas. His Lab’s research is focused on understanding the mechanisms that generate biological diversity. He uses ecological, physiological, genetic, genomic, and systematic approaches to experimental and field studies of life history evolution, adaptation, chemical ecology, sexual isolation, and speciation. Much of his work involves studying the relationships between desert Drosophila and their host plants.

If you would like to talk to Bill, please contact Mike Ritchie.

Bill Etges’ website


(Tuesday) 1:00 pm - 2:00 pm


Dyer's Brae Seminar Room

Dyers Brae, School of Biology, University of St Andrews, St Andrews, Greenside Place, Fife, KY16 9TH, UK


Carolin Kosiol, Shoko Sugasawa, & Nora Carlsonck202@st-andrews.ac.uk, ss244@st-andrews.ac.uk, nc54@st-andrews.ac.uk Dyers Brae, University of St Andrews, St Andrews, Fife, KY16 9TH, UK