Meeting Abstract

22.2  Thursday, Jan. 3  Environmentally-induced stress modifies maternal deposition of yolk hormones in the lizard Anolis carolinensis WALGUARNERY, JW*; LOVERN, MB; University of Tennessee, Knoxville; Oklahoma State University, Stillwater jwalguar@utk.edu

The regulation and transfer of maternal hormones to yolk is increasingly seen as a link between adult environment, reproductive physiology, and offspring phenotype. Stress induced corticosterone (CORT) is generally understood to impact reproduction through widespread physiological regulation and the suppression of the gonadal hormones testosterone (T) and estradiol (E2), although these effects appear highly variable among, and even within, species. Here we consider the effect of a treatment to increase endogenous maternal plasma CORT on yolk CORT, T and E2 in the lizard Anolis carolinensis. Reproductive females were held in either large (75 L) or small (3.8 L) laboratory enclosures. We hypothesized that the smaller of these would impose a low but consequential level of chronic stress. After six weeks in captivity, animals housed in large enclosures showed no significant difference in plasma CORT relative to free-living animals sampled in the field, whereas those housed in small enclosures exhibited increased CORT and the expected reciprocal decrease in plasma T. The chronic elevation of CORT occurred without indicative differences in the predominant color phase of the animals or in total reproductive output. Rather, females in small enclosures produced smaller eggs more frequently and with yolks of higher E2 concentration. Therefore, in contrast to earlier investigations, these results demonstrate a significant association between maternal plasma and yolk hormones in A. carolinensis. Disparities between these studies in correlative evidence suggest potentially complex causal relationships and underscore the need for more comprehensive consideration of ecological and physiological interactions in reptile endocrinology.