Meeting Abstract
Many organisms in montane environments live in isolated populations along environmental gradients. If gene flow among populations is restricted, small populations may become adapted to local environmental stressors. Chrysomela aeneicollis, are leaf beetles living at high elevation (2400-3600 m) in the Eastern Sierra Nevada mountains of California, which experience large diurnal temperature fluctuations during the summer growing season. Allele frequency variation is unusually high for three genes associated with central metabolism in these populations: phosphoglucoisomerase (PGI), Cytochrome Oxidase II (COII), and Succinate Dehydrogenase (SDH), and these genes vary greatly along a 75 km latitudinal thermal gradient. Prior studies suggest that PGI and COII genotype affect physiological and reproductive characters. Our initial results suggested that all mutations of COII are synonymous. However, using next-generation sequencing and Pool-Seq analysis, we were able to conduct larger-scale comparisons of the mitochondrial genome for these willow beetle populations. We identified single nucleotide polymorphisms (SNPs) and across the mitochondrial genome. With these data, we have discovered additional synonymous as well as non-synonymous substitutions in protein coding genes in the mitochondria, and found sequence variation within tRNA genes that may be influenced by temperature. These data will help us understand the genetic basis for mitochondrial differences in performance and fitness characters in future studies.
