Meeting Abstract
Many montane organisms live in fragmented populations that are especially vulnerable to climate change. The ability of populations to persist depends on whether they possess genetic variation in their capacity to respond and adapt to altered environments. In the Sierra Nevada Mountains, the willow leaf beetle Chrysomela aeneicollis occurs at high elevations and experiences variable environmental temperatures, ranging from below freezing to above 30 ° C in a 24 hour period. With increased availability of Next-Generation Sequencing, whole-genome approaches to non-model species are more accessible. Using Pool-seq, we examined how metabolic genes differ among three populations of willow beetles living along this latitudinal thermal gradient, as well as along an elevational (2800-3200m) gradient in the Bishop Creek Drainage. Across geographic clines, the enzyme locus phosphoglucose isomerase (Pgi), the FeS subunit of succinate dehydrogenase (Sdhb), lactate dehydrogenase (Ldh), and NADP dependent mitochondrial isocitrate dehydrogenase (Idh2) showed significantly higher genetic differentiation than 26 other examined loci. Pgi and Idh2 show clinal genetic differentiation across latitude, while Sdhb and Ldh show clinal genetic differentiation across elevation. Clinal variation along geographic gradients suggests that temperature and hypoxia act as selective pressures on study populations and that local adaptation is happening between populations less than 1km apart.
