Western Fence Lizard

David McMillan's research investigates the western fence lizard, Sceloporus occidentalis. This lizard lives throughout California, Oregon, and Washington at many different altitudes. Over such a large geographic range, there is a large fluctuation in temperature that can cause heat or cold stress in this species. During these periods of temperature stress, many proteins can be less efficient in the way they work or they can stop working altogether. One way that S. occidentalis (and many other organisms) responds to this stress is by producing a special group of proteins called heat shock proteins (Hsps). These Hsps function by repairing other proteins in the cell that have become damaged by temperature stress; however this repair requires the use of cellular energy in the form of ATP. The drawback of making and using Hsps is that it can take cellular energy away from other functions that the animal needs to do, like feeding or running away from a predator. This means that the animal is only going to make Hsps if it needs to. For a species of animal living over a large area, like the western fence lizard, animals living in habitats with different temperatures may be experience differing amounts of stress. As a result, different populations may evolve so that they do not need to produce as many heat shock proteins. The goal of my research is to investigate whether or not populations of S. occidentalis do differ in the amount of heat shock proteins they produce and whether or not lizards from different areas are in fact adapted to their local environment.