Wed Nov 18 // Dr. Elizabeth Rideout // Department of Cellular and Physiological Sciences, University of British Columbia

Dr. Elizabeth Rideout
​Department of Cellular and Physiological Sciences, UBC 
Molecular mechanisms of sex-specific body size plasticity in Drosophila

The ability to adjust body size in response to nutrients differs between the sexes in most species, including mammals. Yet the molecular mechanisms underlying this sex-specific body size plasticity remain unknown. In our work, we used the fruit fly, Drosophila melanogaster, to reveal the molecular mechanisms underlying the sex difference in body size plasticity. Normally, the magnitude of the body size increase in response to a nutrient-rich diet is higher in female flies. We recently discovered that a nutrient-rich diet augments body size in females and not males because of a female-biased increase in activity of the conserved insulin signaling pathway. We further identified the factors that allow females, and not males, to augment insulin signaling in response to nutrients. This knowledge provides important evidence of how the insulin pathway can be regulated differently in each sex, and provides clues into why there are sex differences in so many phenotypes (e.g. lifespan) and diseases (e.g. type 2 diabetes) associated with the insulin pathway.