This award will enable Professor Frank P. Conte of Oregon State University to collaborate with Dr. Michael C. Geddes at the University of Adelaide, Australia. These investigators will make physiological and biochemical comparisons on the halotolerant brine shrimp that inhabit alkaline and acidic saline lakes in Western Australia. The enzyme complements responsible for cross-membrane transport of ions in the two environmental types of organisms will be isolated, purified and characterized in order to determine whether there has been genetic modification of the sodium pump. The validity of a proposed carbon dioxide-dependent pathway for the production of auxiliary energy needed in osmoregulation will be tested by determining whether or not brine shrimp from acidic environments have a particular enzyme critical to the pathway. Additionally, ecological studies will be conducted to determine the food resources and feeding behavior of the brine shrimp in the acid and alkaline lakes. The purpose of this research is to gain insight into the molecular evolution occurring in cellular ion transport mechanisms. Such adaptations are essential to the survival of organisms in hypersaline environments. Dr. Conte is an expert on the physiology of halotolerance. Dr. Geddes has had extensive experience with saline lakes and the physiology of the Australian brine shrimp, and was one of the original discoverers of the acid brine shrimp locations. The presence of similar species in contrasting environments within close proximity provides an excellent opportunity for this comparative study.
