Understanding the genetic control of a complex polymorphism

了解复杂多态性的遗传控制

• 批准号: BB/V01451X/1
• 负责人: Chris Jiggins
• 金额: $ 73.56万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FV01451X%2F1
• 关键词: Understanding; genetic; control; complex; polymorphism

Animals are hugely varied in their colouration, which can be adapted for a multiplicity of functions including camouflage, warning, sexual signals and thermoregulation. Stable polymorphisms in colouration offer an opportunity to study evolutionary processes including natural selection, gene flow and genetic drift acting in the wild. In some cases, variation in colour is an external indicator of differences between individuals in their physiology, behaviour and other complex traits. Such genetic correlations among colouration and other traits can be important for the maintenance of variation within populations. In some cases, such correlations are due to multiple genes in tight linkage, so-called supergenes, but in other cases complex polymorphisms seem to have a very simple genetic basis. Here we will study genetic correlations in the wood tiger moth, Arctia plantaginis. Males have either yellow or white hindwings, but these morphs also differ in behaviour, pheromones, immune responses and defensive chemistry. In contrast, females show continuous variation in hindwing colour, which is negatively correlated with larval warning colour. The system has many advantages for genetic analysis, being tractable to rear in large numbers and well-studied in the wild. Preliminary work on the male polymorphism has identified a narrow genomic region that controls morph differences, containing just six genes. Here we will identify the gene responsible for the yellow/white polymorphism using gene expression and gene knockdown experiments. Next, we will test whether the complex traits that differ between morphs vary as pleiotropic effects of the major yellow/white locus, or whether they represent variation at other loci perhaps maintained in linkage disequilibrium. We will also explore the genetic architecture of trade-offs in adult and larval colour traits that show more continuous variation. Here, we will take advantage of large pedigrees that are already available for genetic analysis. Additional breeding and phenotyping of families will be carried out with our Co-I Johanna Mappes in Finland. Finally, we will take advantage of large numbers of wild caught individuals already available to study patterns of genetic variation in the wild. In particular, we will test for signatures of balancing selection at loci controlling polymorphic and variable colour phenotypes. We will also test for patterns of association (linkage disequilibrium) between loci controlling multiple traits.In summary, this project offers an exciting opportunity to develop a new evolutionary genetic system. The wood tiger moth is already well studied in the field and laboratory. We know a great deal about its interaction with predators and with the biotic environment, as well as its behaviour and eco-physiology. However, despite many advantages for genetic analysis including ease of rearing in large numbers and relatively small genome, little genetic analysis has been carried out to date. Here we will explore the genetic basis for key traits in this system and explore the action of natural selection in wild populations at a genetic level. This project has the potential for developing an exciting new text-book example, in which evolutionary forces can be studied through from genotype to phenotype to fitness in the wild.

动物的颜色变化很大，可以适应多种功能，包括伪装，警告，性信号和温度调节。色相中的稳定多态性为研究进化过程提供了机会，包括自然选择，基因流和遗传漂移在野外作用。在某些情况下，颜色的变化是个体生理学，行为和其他复杂性状之间差异的外部指标。着色和其他特征之间的这种遗传相关性对于维持人群中的变异可能很重要。在某些情况下，这种相关性是由于多个基因紧密连接，所谓的超基因，但是在其他情况下，复杂的多态性似乎具有非常简单的遗传基础。在这里，我们将研究Arctia Plantaginis的木老虎飞蛾中的遗传相关性。雄性具有黄色或白色后翼，但这些变体的行为，信息素，免疫反应和防御性化学也有所不同。相比之下，女性表现出后卫颜色的连续变化，这与幼虫警告颜色负相关。该系统在遗传分析方面具有许多优势，可以大量培训并在野外进行了充分研究。关于男性多态性的初步工作已经确定了一个狭窄的基因组区域，该基因组区域控制了变形差异，仅包含六个基因。在这里，我们将使用基因表达和基因敲低实验来确定负责黄色/白色多态性的基因。接下来，我们将测试形态之间不同的复杂特征是主要黄色/白色基因座的多效性效应而变化的，还是代表其他基因座的变化，可能维持在链接不平衡中。我们还将探讨成人和幼体色彩特征的遗传结构，这些特质显示出更连续的变化。在这里，我们将利用已经可用于遗传分析的大型血统。我们在芬兰的Johanna Mappes将进行家庭的其他繁殖和表型。最后，我们将利用大量捕获的野生捕获的人来研究野生遗传变异的模式。特别是，我们将测试在控制多态性和可变颜色表型的基因座中平衡选择的签名。我们还将测试控制多个特征的基因座之间的关联模式（链接不平衡）。总而言之，该项目为开发新的进化遗传系统提供了令人兴奋的机会。木老虎飞蛾已经在野外和实验室进行了很好的研究。我们对其与捕食者以及生物环境及其行为和生态生理学的相互作用了解很多。但是，尽管遗传分析有许多优势，包括大量饲养和相对较小的基因组，但迄今为止很少进行遗传分析。在这里，我们将探索该系统中关键特征的遗传基础，并在遗传水平上探索自然选择的作用。该项目具有开发一个令人兴奋的新教科书示例的潜力，其中可以从基因型到表型再到野外健身的进化力量。