Speaker: Alexander Shingleton, Ph.D., Associate Professor, Biological Sciences, University of Illinois, Chicago
Topic: Stability in the Face of Change: How Hormones Regulate and Coordinate Growth Across Environmental Conditions in Drosophila
Body size and the relative sizes of parts within the body are among the most distinguishing characteristics of a species. Nevertheless, we have a poor understanding of the developmental mechanisms that regulate and coordinate growth among body parts to ensure that final body size and proportion match the functional requirements of an animal. These developmental mechanisms must satisfy two contrasting requirements: On the one had they must be plastic to generate different body sizes under different environmental conditions; on the other they must be robust to generate reliable body proportions regardless of overall body size. Our research focuses on elucidating the developmental mechanisms that regulate and coordinate growth within and among body parts, particularly in response to environmental variation, using Drosophila as a model organism. In this talk I will focus on a relative newcomer to the environmental regulation of growth and body size in insects: the steroid hormone ecdysone. Canonically, ecdysone is a regulator of developmental transitions and was thought to control body size primarily by regulating the duration of growth. More recent evidence from ours and others’ labs, however, has implicated ecdysone in the regulation and coordination of growth-rate and patterning under different environmental conditions. A major challenge in this research, however, is that ecdysone levels undergo a series of characteristic fluctuations during Drosophila development, and the environment affects the dynamics of these fluctuations. We are interested in modeling these dynamics as a way of generating testable hypotheses about how ecdysone regulates growth and development to produce robust pattern across a range of body sizes under different environmental conditions. Ultimately, our goal is to better understand how plasticity and robustness are achieved by the same developmental system, so that developing animals phenotypically match their environment.