Nathan Rank Sonoma State University Local adaptation in montane leaf beetles Introduction & collaborators (Page 1 of 4) Introduction & Collaborators Enzyme polymorphisms Environmental Gradients & Stress Proteins Study Objectives Research Home See also research summary. Adult beetle on a willow North Fork of Big Pine Creek Map of three studied drainages. Black areas indicate ridges above 3,500 meters. My collaborators and I are studying local adaptation for the leaf beetle Chrysomela aeneicollis living in three drainages of the Sierra Nevada: the southern Big Pine Creek (BPC) the middle Bishop Creek (BC) and the northern Rock Creek (RC). Beetles live along steep elevation gradients (2000-3000 meters) in these drainages in eastern California. We are using a variety of approaches to study thermal adaptation in these montane populations Introduction Beetles live in isolated patches with limited exchange of migrants among them. This enhances the potential for adaptation to local environmental conditions. Variation at polymorphic enzymes can be used to measure genetic divergence among populations. I studied enzyme polymorphisms in RC, BC, and BPC using the polymorphic enzymes adenylate kinase (AK), isocitrate dehydrogenase (IDH), mannose phosphate isomerase (MPI), phosphoglucose isomerase (PGI), and phosphoglucomutase (PGM). Differentiation was among drainages was moderate for most enzymes, but it was much greater for the enzyme PGI, which indicates that natural selection acts on PGI alleles. My collaborators and I are presently studying thermal adaptation and the adaptive significance of PGI variation. We have found that beetles in different drainages experience different air temperatures and that beetles in the warmest drainage, BPC, produce significantly more stress proteins than those in cool drainages. Further research will focus on the relationship between PGI genotype, environmental variation, and beetle performance. Collaborators Professor Elizabeth Dahlhoff is an evolutionary physiologist at Santa Clara University. She and her undergraduate students are participating in the field work, characterizing stress proteins from natural populations, and studying the functional properties of metabolic enzymes. Dr. John Smiley of the Big Creek Reserve of the University of California's Natural Reserve System has participated in the field work and sample collection. Previous Page Next Page Research Home|Nathan Rank's Homepage |Department of Biology | Sonoma State University January 23, 1999 NER