Five ways to skin a cat: An unexpected diversity of stress profiles in five species of ground squirrels

Abstract

Event Abstract Back to Event Five ways to skin a cat: An unexpected diversity of stress profiles in five species of ground squirrels Brendan Delehanty1* and Rudy Boonstra1 1 University of Toronto at Scarborough, Biological Sciences, Canada Comparative physiologists often hypothesize that animals facing similar problems will have similar solutions; that is, we expect general patterns to emerge. The alternative hypothesis is that few, if any, patterns will emerge because each species is able to so finely manipulate its physiology that there are any number of ways to solve the same problem. We studied stress axis (hypothalamic-pituitary-adrenal axis) function over the course of the breeding season in a group of closely related ground squirrel species. Because the stress axis is highly conserved among vertebrates in terms of its basic functioning, and because all of the ground squirrel species we studied face similar reproductive challenges (all are hibernators that compete for mating opportunities shortly upon emerging from hibernation), we expected that species sharing similar life history strategies would have similar stress profiles. For each species we obtained pre- and post-breeding stress profiles of males that included stress-induced glucocorticoid (GC) levels, GC levels in response to a hormone challenge protocol (dexamethasone suppression and ACTH stimulation), blood glucose levels, free fatty acids, and complete blood counts. We found that life history did not predict stress profile: each species had a unique stress profile, with no two species sharing even basic trends in GC levels and binding capacity. Trends in total GC concentrations, GC binding capacity, and free GC concentrations over the course of the breeding season varied between all 5 species studied. Moreover, the downstream measures of stress (glucose, free fatty acids, hematocrit, complete blood counts) showed similar variability and could not be predicted from simple measures of GC concentrations. We conclude that many of our simplifying assumptions about how the stress axis supports or constrains reproduction need to be revisited. Acknowledgements Supported by NSERC grant to R.B. and NSTP Grant to B.D. Keywords: downstream effects, Glucocorticoids, ground squirrels, Reproduction, stress profiles Conference: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology, Ann Arbor, United States, 13 Jul - 16 Jul, 2011. Presentation Type: Poster Topic: Stress hormones Citation: Delehanty B and Boonstra R (2011). Five ways to skin a cat: An unexpected diversity of stress profiles in five species of ground squirrels. Front. Endocrinol. Conference Abstract: NASCE 2011: The inaugural meeting of the North American Society for Comparative Endocrinology. doi: 10.3389/conf.fendo.2011.04.00125 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 20 Jul 2011; Published Online: 09 Aug 2011. * Correspondence: Mr. Brendan Delehanty, University of Toronto at Scarborough, Biological Sciences, Toronto, ON, M1C 1A4, Canada, brendan.delehanty@utoronto.ca Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Brendan Delehanty Rudy Boonstra Google Brendan Delehanty Rudy Boonstra Google Scholar Brendan Delehanty Rudy Boonstra PubMed Brendan Delehanty Rudy Boonstra Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.