DISSERTATION RESEARCH: A Measured Genotype Examination of the Effects of Dominance and Epistasis on Heritable Genetic Variation Across a Bottleneck

世代间性状的变化取决于对个体之间可遗传差异的选择。理论预测，当基因效应相互独立时，个体之间的可遗传差异将随着时间的推移在小种群中缩小，从而限制未来的适应。然而，当基因的影响取决于个体中存在的其他基因时，这种可遗传变异的损失可能是有限的。研究人员将在一系列来自近亲交配品系的40个小实验鼠群体中检查可遗传变异随世代的变化。他们之前已经在这些群体中确定了影响体重、脂肪重量和尾长的基因座，并发现预期的可遗传变异的丢失并没有发生。研究人员将测量这些基因座上的基因类型及其对可遗传变异的贡献，确定上下文相关的基因效应如何防止小种群中遗传变异的丧失。这项研究对于理解小种群物种形成和适应的遗传基础很重要。它对保护少数种群及其适应新环境的能力具有重要影响。基因效应的上下文相关性质对于我们理解复杂疾病的遗传基础也有重要的影响。

Changes in traits across generations depend on selection of heritable differences between individuals. Theory predicts that heritable differences between individuals will be reduced in small populations over time, limiting future adaptation, when gene-effects are independent of each other. However, when the effects of genes change depending on what other genes are present in the individual this loss of heritable variation may be limited. The investigators will examine changes in heritable variation over generations in a series of forty small experimental mouse populations derived from the cross of inbred strains. They had previously identified loci affecting body weight, fatpad weight, and tail length in these populations and found that the expected loss of heritable variance did not occur. The investigators will measure the genotypes at these loci and their contributions to heritable variance, identifying how context-dependent gene-effects prevent the loss of heritable variation in small populations.This research is important for understanding the genetic bases of species formation and adaptation in small populations. It has important implications for conservation of small populations and their ability to adapt to new circumstances. The context-dependent nature of gene-effects also has important consequences for our understanding of the genetic bases of complex diseases.