Nancy J. Berner - US grants

9508628 Berner Organisms generate heat by the breakdown of fuels during cellular metabolism. In endotherms, metabolic heat can be produced fast enough to raise body temperature significantly above that of the surroundings. In ectotherms, rates of metabolic heat production are so low that body temperature is determined primarily by the surrounding environment. The aim of this research is to determine the mechanisms that permit endotherms to produce heat at a greater rate than can ectotherms. High rates of metabolic heat production are usually linked to high rates of oxygen consumption and production of usable chemical potential energy. These last two processes occur in subcellular organelles, the mitochondria. This research will contrast the rate of oxygen consumption and chemical potential energy (ATP) production by the mitochondria of endotherms and ectotherms under a variety of conditions. Experimental treatments will include varying the temperature at which the mitochondria work and varying the fuels provided to the mitochondria as they perform their metabolic functions. The research will improve understanding of the mechanisms responsible for metabolic differences between endotherms and ectotherms and of how these differences evolved.

Berner 9805808 The activities to be undertaken in this Research Enhancement POWRE project include learning new methods at an external site, perfecting the new methods at the home institution, applying the new methods to the PI's research program, and forging a new collaborative relationship with colleagues at another institution. Academic year 1998-99 is the sabbatical leave year of the P1. The PI will spend one semester in the lab. The purpose of the trip Is two-fold: to learn the new lab methods which will broaden the PI's research' program and to solidify a developing collaborative relationship. The PI will spend the second semester perfecting the techniques at the home institution with the animal models commonly used in the PI's lab. Upon working out the methods in the home lab, the PI will begin applying the new methods to the ongoing research project of the P1. The PI will involve undergraduate in this part of the project and the 'proposal includes summer salary for two students for the summer, This proposal is particularly suited to a POWRE award. It makes possible significant professional advancement of the PI by broadening the scope of the research project through learning new methods, and it increases leadership opportunities by providing funding for undergraduate research. Completion of these activities would not be possible without funding from the NSF which provides necessary salaries and supplies, and the ability to dedicate time to these activities.

Acclimatization is a process by which individual organisms vary their characteristics in response to some aspect or aspects of their environment. Acclimatization is reversible, which distinguishes it from adaptation, generally defined as an evolutionary response to long-term environmental alteration. Acclimatization is an important mechanism by which organisms respond to fluctuations in their surroundings. Modifications in characteristics brought on by natural seasonal temperature differences are of particular interest, and are generally studied in animals acclimated to specific temperatures in the laboratory that mimic temperatures found in their natural environment. Thus, both acclimatization to natural seasonal temperatures and acclimation to various temperatures in the laboratory have been well described across numerous taxa, vertebrate and invertebrate as well as in plants. Despite the widespread nature of seasonal thermal acclimatization and acclimation, mechanisms controlling and coordinating these processes remain elusive.
This research uses laboratory acclimation experiments on an amphibian model to clarify cellular, molecular and environmental mechanisms responsible for controlling and coordinating thermal acclimation in a single species, the Eastern red spotted newt. It will provide one of the most complete investigations of acclimation in a single cold-blooded vertebrate species, and will lead to insights about mechanisms of acclimatization in their natural environment. The PI, along with undergraduate co-workers, will investigate the expression of genes that are related to temperature regulation and acclimation processes. The investigators will determine the role of particular cellular membrane components in the acclimation process by artificially changing membrane composition through dietary manipulations. The use of mass spectrometry will allow them to identify specific membrane components critical to the activity of metabolic enzymes. Laboratory acclimation experiments controlling day length and temperature will determine the environmental cue most important to the acclimation process. Knowing how environments impact individual characteristics will lead to a better appreciation of how our currently changing global temperatures might impact species distribution and survival. Such information will be critical in determining best conservation practices in the face our changing global environment.
This project will have considerable impact beyond the broad scientific impact of the research itself. As a biology professor at a liberal arts institution, the PI consistently publishes with undergraduate co-authors in leading scientific journals. Funding will provide summer stipends for ten to twelve undergraduate students and travel funds for these students to attend national meetings to present their research. In addition, the PI will coordinate with the University's high school minority program "the Bridge Program in Math and Science" to increase the involvement of minority students in research. One or two of the summer research students each year will be entering freshmen that participated during previous summers in the Bridge Program. Engaging minority students in research and involving them in a research community early in their college career will increase the likelihood that they will enter and stay in STEM disciplines.