STEARNS, M.H.*; THOMBRE, R.M.; GILLEN, C.M.; ITAGAKI, H.; Kenyon College; Kenyon College; Kenyon College; Kenyon College: The metabolic rates and the expression of a cation-chloride cotransport protein during development in larval Manduca sexta.

Investigations of metabolic rates in organisms of different sizes typically involve different individuals of different species. Using the larvae of the moth Manduca sexta, we have measured the metabolic rates of identified individuals throughout their larval development, during which they increase in weight by 4 orders of magnitude. Our initial results indicate that the slope of the log metabolic rate versus log body weight relationship did not change during larval development, remaining consistent across the 5 larval instars. In addition, we investigated the expression of masBSC, a cation-chloride co-transport protein, in the gut over larval development to see where it is expressed, and if its expression varied in concert with the massive growth of the larva. Using immunohistochemistry, we found strong expression of masBSC on the luminal side of the midgut with little detectable variation in its expression over development. We are continuing our investigation using more quantitative techniques. (Supported by the Kenyon Summer Science Scholar Fellowships.)