Meeting Abstract

P1.160  Sunday, Jan. 4  Does Maternal Stress Alter Egg Composition? JOHNSTON, Gwynne I.H.*; SHAFFERY, Heather M.; MOORE, Michael C.; Arizona State University; Arizona State University; Arizona State University gjohnston@asu.edu

Many studies have shown that treating females with hormones can alter the phenotype of their offspring. These phenotypic effects could be due solely to changes in hormone levels in the eggs. Or, hormonal treatment of females could cause them to alter the composition of their eggs, which could then affect offspring phenotype. These hypotheses are not mutually exclusive, but to date most studies have overlooked the possibility of egg compositional changes. In a previous study, we treated female tree lizards (Urosaurus ornatus) with a pharmacological dose of corticosterone, the primary hormone involved in the stress response, and found that eggs from treated females had less egg mass but were not different in size. In this study, we treated females with a physiological level of corticosterone to determine if it affected egg composition. We found no significant differences in any of the egg compositional aspects measured – average egg mass or size, water content, or amount of lipids, proteins, or salts. These results suggest that offspring phenotypic effects due to maternal treatment with corticosteroids are primarily caused by hormonal changes in the eggs and not changes in egg composition.