Meeting Abstract

P2.112  Sunday, Jan. 5 15:30  Plasticity and integration in mangrove rivulus: arginine vasotocin as a potential mediator of salinity-induced phenotypes. ROBINSON, S.L.*; EARLEY, R.L.; Univ. of Alabama, Tuscaloosa; Univ. of Alabama, Tuscaloosa stephrobinson08@gmail.com

Developmental plasticity can drive phenotypic variation and evolutionary change, but the mechanisms powering plasticity are not well understood. Current research demonstrates that endocrine signaling pathways can translate environmental variability into differential expression of an arsenal of phenotypic characteristics such as morphology, mating displays, sexual development, and behavior. By examining these characteristics, we can quantify elaborate trait interaction networks and determine how trait linkages change along an environmental gradient. Our powerful model organism—the self-fertilizing, hermaphroditic killifish, Kryptolebias marmoratus—allows us to isolate the effects of genetic variation and attribute deviations from the norm to environmental influences. Neuroendocrine pathways can help us look beyond hormones and understand how plasticity and trait integration interact and change during development. The arginine vasotocin (AVT) pathway in teleost fishes is one such route. AVT expression is sensitive to environmental parameters such as salinity, possibly because of its role in osmoregulation. AVT also modulates the production of steroid hormones, which in turn, affect the phenotype. We aimed to examine variation in color, body shape, behavior, and growth rate in genetically identical rivulus raised in different salinity conditions, and to determine the relationship between these traits and AVT neuron cell size and number. Based on previous research and preliminary data, we hypothesize any deviation from normal salinity will result in more, yet smaller, AVT neurons, as well as differences in color, body shape, behavior, and growth rate across genotypes within the same population.