Meeting Abstract

P3.66  Wednesday, Jan. 6  The impact of incubation environmental stress on the Angiotensin II receptor density in tissues of embryonic American alligators (Alligator mississippiensis) ARNOLD, C*; LAMB, B; CROSSLEY II, D A; U N Dakota; U Texas A&M; U N Dakota catherine.arnold@und.edu

Embryonic reptiles are unique among vertebrates due to the virtual absence of parental care following ovipostion in most species and the relatively high eggshell permeability in comparison to birds. Typically, reptile eggs develop in a nest that is either subterranean or in a mound structure in which the surrounding media can vary in abiotic stress. Nests of the American alligator (A mississippiensis) are subjected to a variety of conditions due to nest structure, periods of drought, as well as flooding conditions. These bouts of developmental stress have the capacity to alter gene expression and ultimately both physiological and morphological maturation of organs systems. While this is intuitive the impact of embryonic stress on the gene expression is largely a mystery. Therefore this study was undertaken to determine if Angiotensin II (Ang II) receptor density, a key CV regulatory component, is altered by developmental challenges in embryonic alligators. Acute dehydration, chronic hypoxic and temperature oscillation were used as stressors and Ang II receptor density was determined at 70% and 90% of incubation in the heart, lung, CAM and liver. Receptor density in the heart was highest in early development relative to the loading control. At 90% receptor density was highest in lung tissue relative to the loading control. Dehydration stress increased receptor density in heart tissue at 90% of incubation with little affects of the remaining stressors. The data indicate that this receptor exhibits marked plasticity during embryonic development and during periods of stress. Supported by NSF Career award IBN IOS-0845741 to DAC.