Research Information

RESEARCH INTERESTS

My research is a study of how a particular ectotherm, the Eastern red spotted newt (Notophthalmus viridescens viridescens) acclimatizes to summer and winter temperature conditions. The adults of this species are fully aquatic and as ectotherms are the same temperature as their surrounding water. In Franklin County, TN, the temperature of the ponds in which they are found can range widely between summer and winter. These animals remain active in winter and in fact breed during that time. I am studying these animals for possible links between behavioral thermoregulation and their biochemistry to determine what seasonal modifications may take place that allow these animals to remain active year round despite large temperature changes.

My project has three basic approaches: behavioral thermoregulatory studies with animals in a thermal gradient to establish their ability to behaviorally thermoregulate; whole animal oxygen consumption experiments at varying temperatures to estabilish that behavioral thermoregulation has consequences on the whole animal level; and metabolic enzyme activity assays, again at a variety of temperatures to with the goals of establishing that the behavioral thermoregulation could have an effect on enzymes, and of investigating links between behavior and biochemistry.

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My project took me to Australia on my sabbatical from August 2005 to August 2006. During that time, as a Visiting Principal Fellow at the University of Wollongong in Wollongong, New South Wales in the lab of Dr. A. J. Hulbert, I learned about lipid biochemistry. This collaboration allowed me to investigate seasonal changes in the fatty acid composition and phospholipid species of muscle and liver membrane which might influence membrane-bound enzyme activities.

I have several projects currently underway in which I am involving various undergraduate students. We are investigating seasonal changes in plasma corticosterone and testosterone levels in field and laboratory-maintained newts (with a Dr. L. Michael Romero of Tufts University). We are also acclimating some newts to summer and winter conditions in the laboratory to investigate two things. First, to see if they will acclimate to seasonal conditions in the lab, and second to see if all the parameters we have been measuring acclimate together, or if the changes in the field are merely correlations. We will also be investigating mitochondrial volume density and cristae surface area using TEM in collaboration with the Electron Microscopy labs at Vanderbilt University. Finally, we are running electrophoretic gels to investigate the presence of isozymes of the enzymes of interest to us.

Papers on this topic:

Berner, N.J. and E.P. Bessay* (2006) Correlation of seasonal acclimatization in metabolic enzyme activity with preferred body temperature in the Easter red spotted newt (Notophthalmus viridescens viridescens). Comparative Biochemistry and Physiology A. 144/4: 429 – 436.

Berner, N.J. and A.J. Hulbert (2005) Seasonal fatty acid composition of skeletal muscle from the Eastern red spotted newt (Notophthalmus viridescens viridescens) of North America. ANZSCPB Proceedings.

Berner, N.J., R.E. Puckett* and B.J. Waffa* (2005) Identifying possible structural differences in some metabolic enzymes of summer- and winter-acclimatized Eastern red spotted newts (Notophthalmus viridescens viridescens). Southeastern Biology. 52(2): 189. (Abstract)

Puckett, R.E. * and N.J. Berner (2005) The effect of seasonal acclimatization on the standard metabolic rate of Eastern red spotted newts (Notophthalmus viridescens viridescens). Southeastern Biology. 52(2): 188. (Abstract)

Berner, N.J. (2004) Seasonal acclimatization of behavioral thermoregulation and enzyme activity in the Easter red spotted newt. Presented at the “Life in the Cold” Conference July 25 – 31, Vancouver, BC - Seward, Alaska. (Abstract)

Bessay, E.P.* and N.J. Berner (2000) . Effect of acclimatization to summer and winter conditions on metabolic enzyme activities in the Eastern red spotted newt (Notophthalmus viridescens viridescens). J. Tenn. Acad. Sci. 75(1-2):33.(Abstract: Awarded Best Student Paper Presentation)

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Grants on this topic:

Appalachian College Association fellowship “Learning techniques and applying them to determining the effects of seasonal acclimatization on membrane properties of the Eastern red spotted newt (Notophthalmus viridescens viridescens)” in the amount of $28,240 for July, 2005 – June, 2006.

Institute for Arctic Biology travel grant in the amount of $500 to attend the 1998 Annual meeting of the the international conference “Life in the Cold” Vancouver BC – Seward Alaska, July 25 – August 1, 2004.

Appalachian College Association travel grant in the amount of $500 to attend the 1998 Annual meeting of the the international conference “Life in the Cold” Vancouver BC – Seward Alaska, July 25 – August 1, 2004.

A grant from the Faculty Research and Development Funds in the amount of $5,000 from Sewanee: The University of the South for 6/05 – 6/06.

A grant from the Faculty Research Fund in the amount of $3,000 from the University of the South for 6/05 – 6/05.

A grant from Faculty Development Fund in the amount of $1,151 to attend from the University of the South to attend the international conference “Life in the Cold” Vancouver BC – Seward Alaska, July 25 – August 1, 2004.

A grant from the Faculty Research Fund in the amount of $3,000 from the University of the South for 6/03 – 6/04.

From DuPont Foundation through the University of the South “A transmission electron microscopical analysis of seasonal metabolic accommodations in the aquatic newt” $5168 with Dr. Karen McGlothlin, June – July, 2002.

National Science Foundation Research Experience for Undergraduates Supplement to fund summer salary for two students summer, 2000. $5,000.

National Science Foundation award "POWRE: Learning and application of new methods to the study of mitochondrial heat generating mechanisms in endothermic and ectothermic vertebrates" in the amount of $68,000 for July 15, 1998 - Dec 31, 2000.

For information (publications and grants) on past research projects and interests please see my CV.

*denotes undergraduate coauthors