Nancy Pruitt (Professor)

Department of Biology, Colgate University

Phone: 315.228.7398 Fax: 315.228.7997

E-Mail: NPruitt@mail.colgate.edu

Research Interests: Cellular adaptations to temperature in ectotherms, lipid metabolism, enzyme kinetics. [Details]

Teaching Interests: Animal physiology, cellular biology, comparative physiology. [Details]

Student Research   Publications  

Colgate Teaching & Research Directory  

---

Nancy Pruitt

Research Interests:

I am interested in the phenomenon of freeze-tolerance: the ability of some animals to withstand the formation of ice in their body during the coldest months of the year. Most cold-blooded species are freeze-avoiders. They have evolved elaborate mechanisms to avoid the formation of internal ice, even when temperatures fall below the melting point of their body fluids. Some insects, however, and a small number of vertebrates not only survive freezing, they have adaptations that induce ice formation at relatively high subzero temperatures. Body ice has the potential to be quite devastating, both to the delicate cellular architecture and the water and solute balance of the cells. What cellular and molecular adaptations do freeze-tolerant species have that prevent ice damage?

Using the freeze-tolerant larvae of the goldenrod gall fly, my students and I have identified several adaptations in the structure of cellular membranes that may relate to freeze tolerance. These fly larvae are freeze-susceptible in the early weeks of the fall, but undergo a physiological change that renders them freeze tolerant in early October. By comparing larvae collected in August and September with those collected in November and December, we found alterations in both fatty acid and phospholipid polar head groups that appear to be a compromise between the need to preserve membrane flexibility at low temperatures and prevent the loss of the barrier properties of the membrane that can occur when water is tied up as ice. Currently we are searching for cryoprotective proteins using a combination of standard biochemical techniques and molecular biology.

Development of Teaching Materials

Introductory Biology is a critical course in the curriculum of early science students. Traditional courses at the introductory level have focused on surveys of life on Earth or overviews of the entire field. One of my interests is in developing teaching materials for introductory students that focus on the theme of evolution -- the concept that informs all of biology -- and presents the field as a series of interconnected concepts. With coauthors Larry Underwood and Bill Surver, I have written a textbook that remains true to these ideals. BioInquiry is published by John Wiley and Sons. The first edition came out in January of 2000 and the second edition appeared in 2003.  The book is currently being updated to a third edition.

In addition, I have written a problems workbook and student study guide that accompanies Cell Biology: A Molecular Approach by Gerald Karp. That book is currently being updated to a fourth edition.

Teaching Interests:

My goals in the classroom and laboratory are to guide students to self-learning. The best way to learn is to do, so my courses are designed to maximize the doing, whether it be problem solving, designing experiments in the laboratory, or investigating ideas in the literature of biology. The courses I teach include Introductory Biology, Cell Biology, Human Physiology, and a research course on animal adaptations to the environment.

Student Research:

Nine students worked in my lab during 2003:

Changrui Lu ('05) and Becky Ortolano ('04) analyzed lipid membrane components from freeze-tolerant and freeze-susceptible gall fly larvae.  Changrui's work has resulted in a manuscript currently in press with the Journal of Experimental Biology.

Jash Datta ('06), Jim Skiba ('03), and Jason Wolf ('04) have been working to characterize a unique cryoprotective protein found in freeze-tolerant gall fly larvae.

Michelle Hellman ('04) and John Biatowas ('04) used a technique called subtractive hybridization to search for unique RNA transcripts specific to freeze tolerant larvae.

Chrissy Besanceney ('04) and Varun Sondhi ('05) developed a liposome fusion protocol for altering the lipid composition of cell membranes in fat body cells from gall fly larvae.  We will use this protocol to test the effects of altering lipid membrane composition on the ability to survive freezing.

Recent Publications:

Books:

Pruitt, N. L. 1996. Cell Biology: Problems Workbook and Study Guide. John Wiley and Sons. New York. 295 pp. (Accompanies the Cell Biology text by Gerald Karp)
[1999 Second Edition]
[2001 Third Edition]

[Fourth Edition forthcoming in 2004]

Pruitt, N. L., L. S. Underwood and W. Surver. 2000. BioInquiry: Making Connections in Biology. John Wiley and Sons. New York. (An introductory textbook emphasizing concepts instead of facts.) 512 pp.

[2003 Second Edition]

[Third Edition forthcoming in 2007]

Papers:

Skeer, J. M., N. L. Pruitt and D. B. Sattelle. 1992. Pharmacologically distinct calcium channels are present in insect nervous system and skeletal muscle. Insect Biochem. Molec. Biol. 22(6):539-545.

Bennett, V. A., N. L. Pruitt and R. E. Lee, Jr. 1997. Seasonal changes in fatty acid composition associated with cold-hardening in third instar larvae of Eurosta solidaginis. J. Comp. Physiol. B 167 (4): 249-255.

Hoopes, B. C., N. L. Pruitt, K. Baier and S. Brooks. 1998. Signal transduction and the control of the cell cycle in yeast (Saccharomyces cerevisiae): A collaborative laboratory exercise. IN: Karcher, S. J. ,ed. Tested Studies for Laboratory Teaching

Pruitt, N. L. and C. Lu.  IN PRESS.  Seasonal changes in phospholipid class and class-specific fatty acid composition associated with the onset of freeze tolerance in third instar larvae of Eurosta solidaginis.  J. Experimental Biol.