Tues Nov 5 // Shaping physiological phenotypes: The influence of genomic, developmental, and environmental inputs on salt and water balance in freshwater fishes

Dr. Alex Zimmer
Department of Biology, University of Alberta

10:30AM – 11:30AM, in Biosciences 1102

Ecological and evolutionary success of animals depends on the expression of phenotypes that are compatible with their environment. In order to understand how specific physiological phenotypes arise, and the degree of plasticity or flexibility of these phenotypes, it is critical that we integrate the study of physiology across different levels of biological organisation. In my research, I have used ionoregulatory systems (salt and water balance) of freshwater fishes as a model to demonstrate how the genome and environment interact to influence phenotypes and how these interactions change over life history to shape physiological systems. In particular, I have studied how fishes sustain Na+ absorption, a process critical to maintaining internal ion and water balance, over development and in response to a range of environmental conditions (ionic strength, pH, contaminant exposure). In this presentation, I will discuss the molecular mechanisms of Na+ absorption by rainbow trout, how they change over development, and the implications that this has in understanding how fish at different stages of life history respond to changes in environmental conditions. I will also discuss the use of CRISPR/Cas9 gene editing as a tool to knock out genes that regulate Na+ absorption in zebrafish and explore how the resulting reduction in genetic complexity influences the expression and plasticity of phenotypes. This research highlights the importance of integrating molecular, organismal, and environmental physiology to understand how fishes occupy different environmental niches and how they respond to environmental change.