Meeting Abstract

P3.42  Friday, Jan. 6  Effects of Hypoxia and Hyperoxia in Alligator mississippiensis PARRILLA, Leah*; OWERKOWICZ, Tomasz; STEELE, Erin; MORI, Miki; LEE, Amber; HICKS, James; ROURKE, Bryan; California State University, Long Beach; University of California, Irvine leah.parrilla@student.csulb.edu

Oxygen levels have fluctuated between 16% and 36% as shown from burial rates of organic carbon over the past 500 million years (my). This cyclical pattern has been associated with animal extinction and implicated as a driving force for physiological adaptation. We use Alligator mississippiensis (A.M.) as a model species of longevity and adaptability over the last 100my. Incubated A.M. eggs were raised in oxygen conditions of 16%, 21%, 26%, 31%, and 36% representative of oxygen levels over the last 500my. We hypothesized that A.M. raised in hypoxic environments would have constraints on growth, cardiovascular load, metabolic protein expression and possible myosin heavy-chain (MyHC) plasticity related to cardiovascular demands. AM reared in hyperoxia were expected to show plasticity in cardiac isoforms and increased oxygen dependent gene expression. Heart and metabolic activity in the liver were examined at embryonic, hatchling and post-hatchling time points as indicators of phenotypic plasticity to differing oxygen environments. MyHC isoform expression was examined in all chambers. Proteomic analysis was used to identify differentially expressed liver proteins from each oxygen group using two dimensional gel electrophoresis and MALDI-TOF/MS for protein identification. Quantitative PCR was used to measure cardiac gene expression for each oxygen group in the oxygen dependent HIF-1α gene, E3 ubiquitin ligase gene MAFbx involved in the atrophy signaling pathway, and Myostatin involved in hypertrophy. Funded by NSF grant:IOS-0922627 NSF RUI