Collaborative Research: Molecular-genetic Basis of Parallel Adaptation Driven by Coevolutionary Interactions

蝾螈通过分泌一种强有力的神经毒素河豚毒素(TTX)来防御蛇等捕食者，但一些种群和物种的吊袜带蛇已经进化出对TTX的抵抗力。这种抗性的分子机制是已知的，涉及的基因之一也是已知的，这为研究具有明显适应价值的性状的进化遗传学提供了一个极好的机会。这些研究将包括调查不同种群和物种对TTX抗性差异的遗传差异，并对自然选择在抗性进化中的作用进行分子遗传学评估。有几个因素可能是在多个种群中存在耐药性的基础。这些是独立进化的多个阶段，跨种群传播，或共同的祖先；这些替代方案将通过分子遗传分析进行测试。这项研究将有助于理清新突变、重组和基因流动在解释表型多样性的地理模式中的作用。该项目将有助于支持行为和分子遗传学的研究生和本科生教育。PIS将通过乌塔什州立大学NSF高级计划、USU多元文化研究奖学金计划和山湖生物站REU计划促进少数族裔和妇女参与科学事业。Snake-Newt系统将继续发展为一个模型，通过外展教育(类似于最近PBS-TV材料和流行媒体上的文章)和博物馆展览向普通公众说明进化过程。

Newts defend themselves from predators such as snakes by secreting a potent nerve poison, tetrodotoxin (TTX), but some populations and species of garter snakes have evolved resistance to TTX. The molecular mechanism for this resistance is known, as is one of the genes involved, providing an excellent opportunity to investigate the evolutionary genetics of a trait that has a clear adaptive value. The studies will include a survey of the genetic differences underlying the variation in resistance to TTX in different populations and species of garter snakes and a molecular genetic evaluation of the role of natural selection in the evolution of resistance. Several factors could underlie the presence of resistance in multiple populations. These are multiple episodes of independent evolution, spread across populations, or shared ancestry; these alternatives will be tested with molecular genetic analyses. The research will result in disentangling the role of novel mutations, recombination, and gene flow in explaining the geographic patterns of phenotypic diversity.This project will help to support graduate and undergraduate education in behavioral and molecular genetics. The PIs will promote the participation of minorities and women in science careers through the Utash State University NSF ADVANCE program, the USU Multicultural Research Fellowship Program, and the Mountain Lake Biological Station REU program. The snake-newt system will continue to be developed as a model to illustrate the evolutionary process to the general public through outreach education (similar to the recent PBS-TV material and articles in popular media) and exhibits in museums.