Meeting Abstract

S5-1.6  Friday, Jan. 4  Yolk steroids in the green anole, a lizard with genotypic sex determination: exploring the environment-mother-offspring link LOVERN, M.B.*; ADAMS, A.L.; Oklahoma State University; Oklahoma State University

The vertebrate egg serves as a main focus of research in our lab. In particular, we are interested in understanding (1) the factors that influence maternal deposition of the steroids testosterone (T) and corticosterone (CORT) into the yolks of developing eggs and (2) the consequences of those maternally-derived steroids to offspring. Such potentially profound maternal effects on offspring phenotype have been documented in a diversity of oviparous species including green anole lizards (Anolis carolinensis), our primary research model. Females of this species produce single-egg clutches every 7-14 days over the course of a four-month breeding season, and there is no parental care exhibited after oviposition, therefore maternal condition may change over the duration of the breeding season. As a consequence, each individual egg produced may be influenced by maternal condition at that time, and if steroid deposition into yolk is condition-dependent, the resulting offspring may be differentially affected. We will review previous data for green anoles that document changes in plasma T in reproductively active females during egg production as well as changes in yolk and embryo T content during egg incubation. We also will highlight our recent advances towards using female diet as a realistic mechanism for manipulating body condition, resulting in changes in egg output and, potentially, yolk T and CORT allocation. Finally, we will discuss, providing data where possible, what we see as the primary challenges as well as opportunities for future work most notably the need for a more proximate understanding of steroid allocation into yolk and for studies that examine the long-term consequences of these steroids on offspring phenotype.