9318549 Oswald Physiological function in adults results from a complex interplay of genetic and environmental factors that act during development, as well as adaptations that can occur during adulthood. The nature and extent of the interactions among these factors is poorly understood. It is the goal of this research to help understand how these factors interact in one particular function: the ability to conserve water by producing concentrated urine. The PI will study the urine concentrating ability (UCA) of the white-footed mice. These mice are an important prey species in the biological community. and naturally occur in a wide variety of habitats from very moist to very dry. They thus provide a sort of "natural experiment" that allows us to examine the effects of different environments on kidney function. To distinguish between differences due to long-term genetic changes between populations of mice on the one hand, and short-term developmental responses on the other, the PI will also study mice raised in the laboratory under different condition of water availability. Because UCA depends not only on the kidney itself, but also on the control of kidney function by hormones, the PI will perform a variety of analyses on tissues from the mice. The PI will measure the levels of the hormone vasopressin in the blood and in the gland that produces it, as well as the kidney's responsiveness to vasopressin. The PI will use light and electron microscopy to study the internal structure of the kidney. The importance of this study lies in its contributions to understanding environmental influence on the development of basic physiological processes, and to understanding the extent to which this key species in the biological community can respond to changing climatic conditions. ***
