Kathleen Gilmour

My lab uses a range of physiological, biochemical and molecular approaches to address research questions under two broad themes.

First, we use the formation of dominance hierarchies in fish and the resultant social stress as a means of studying chronic stress.  Much of this work focuses on salmonid fish, which readily form social hierarchies in the lab.  Typically, hierarchies are formed through aggressive interactions, with dominant fish monopolizing resources that are essential but limited, such as food or shelter.  Subordinate fish are excluded from these key resources and are subjected to agonistic attacks by dominant fish, resulting in chronic stress and prolonged elevation of the glucocorticoid stress hormone cortisol.  Our research questions focus on how the stress axis functions during acute versus chronic stress, as well as the physiological consequences of chronic stress on metabolism, growth and tolerance of environmental challenges such as elevated temperature.

Second, we aim to understand the mechanisms through which fish maintain gas exchange and acid-base balance in diverse environments. Work in this area focuses on mechanisms of gas sensing and ion transport, particularly with respect to the enzyme carbonic anhydrase, which plays key roles in both gas transfer and acid-base balance in a variety of tissues.  Recently we used CRISPR/Cas9 to develop a zebrafish line lacking functional expression of a cytosolic CA isoform, CA17a, and we are using these fish to probe the role of CA17a in ionic regulation and gas sensing.  We are also investigating the dual roles of cortisol as a stress hormone and an ionoregulatory hormone during early development, again using zebrafish.