Dissertation Research: Maintenance of Genetic Variation in an Island System

研究人员将对一组适应性相关基因（主要组织相容性复合体或Mhc）的遗传变异进行调查，这些基因存在于一种当地受威胁的地方性犬科动物--岛狐（Urocyon littoralis）中。 目的是了解自然选择在维持小种群的变异中所起的作用。 这一认识也将有助于更有效地管理濒危的岛屿狐和其他正在减少或受到威胁的物种。 对Mhc多态性的初步调查显示，岛狐的遗传变异达到了前所未有的水平。 研究人员将使用基于PCR（聚合酶链反应）的技术调查岛狐中四个Mhc基因的分子变异，并将其与中性遗传变异的无效模型进行比较。 Mhc基因是脊椎动物免疫功能的组成部分，Mhc的变异影响个体适应性（例如对病原体的抗性或易感性）。 这项研究将试图阐明，通过直接观察和计算机模拟，在一个物种有限的遗传变异，保持遗传变异所必需的自然选择的强度。 这些结果将有直接的影响，保护和管理的岛屿狐狸，以及提供一个更好的理解自然选择的程度上运作的一组重要的免疫基因。

The investigators will conduct a survey of genetic variation for a set of fitness related genes (the Major Histocompatability Complex or Mhc) in a locally threatened endemic canid, the Island fox (Urocyon littoralis). The goal is to understand the role that natural selection has played in maintaining variation in small populations. This understanding will also allow for a more effective management of the endangered Island fox and other species that are declining or threatened. An initial survey of polymorphism at the Mhc has revealed an unprecedented level of genetic variation in Island foxes. The investigators will survey molecular variation of four Mhc genes in Island foxes using PCR (polymerase chain reaction) based techniques, and compare this to the null model of neutral genetic variation. Mhc genes are integral to vertebrate immune function, and variation in the Mhc affects individual fitness (e.g. resistance or susceptibility to pathogens). This study will attempt to illuminate, though direct observation and computer simulation, the strength of natural selection necessary to maintain genetic variation in a species with limited genetic variation. These results will have direct implications for conservation and management of the Island fox, as well as provide a greater understanding of the extent of natural selection operating upon an immunologically important set of genes.