Research Objectives:
Understanding metabolic efficiency in polar organisms is required to help resolve long-standing questions regarding temperature compensation and adaptations to food limitation in polar regions. This project will emphasize the subcellular levels of biological analysis to understand the relationship between development, growth, metabolic rate, and rates and costs of protein synthesis in the antarctic organisms it studies. The group will test the hypothesis that there is a “new” biochemistry for protein synthesis in these antarctic organisms.
The field team will combine their expertise in antarctic larval physiology and the biochemistry and molecular biology of sea urchin development to address an experimental plan that is based on three major objectives.
+ Test the generality of the groups' recent finding of the low cost of protein synthesis in antarctic sea urchin larvae by measuring metabolism and protein synthesis during development of other antarctic echinoderm species.
+ The prediction of a high rate of protein synthesis with low metabolic cost is that growth efficiencies will be high in such organisms. Researchers will directly test that hypothesis by measuring the physiology of protein growth efficiencies in larvae.
+ Explain in specific molecular terms the unique high efficiency of protein synthesis in antarctic sea urchin embryos by studying each of the component processes of protein synthesis (i.e. fraction of ribosomes engaged in protein synthesis, the fraction of mRNA molecules engaged in protein synthesis, average polysome size, and polypeptide elongation rates).
The group will also supplement these measurements on whole population protein synthesis with measurements based on selected individual proteins. At the subcellular level, rates of ATP (Adenosine triphosphate, the energy currency of cells) consumption during protein synthesis will be measured in cell-free translation systems of antarctic sea urchin embryos. The combination of these quantitative analyses will allow scientists to pinpoint those aspects of protein metabolism that result in such extremely high energy-efficiencies.
