Evolutionary mechanisms controlling opsin gene expression variation

控制视蛋白基因表达变异的进化机制

• 批准号: 8762683
• 负责人: KAREN L CARLETON
• 金额: $ 29.92万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8762683
• 关键词: 11 cis Retinal; African; Binding; Biological Models; Cichlids; Circadian Rhythms; Code; Cone; Data Set; Development; Disease susceptibility; Environment; Environmental Risk Factor; Evolution; Fishes; Gene Combinations; Gene Expression; Gene Expression Profile; Genes; Genetic; Genotype; Health; Human; Life; Light; Lighting; Link; Location; Malawi; Maps; Methods; Mutation; Natural Selections; Opsin; Organism; Outcome; Partner in relationship; Pathway Analysis; Peripheral; Phenotype; Photophobia; Plastics; Population; Population Sizes; Quantitative Trait Loci; Relative (related person); Retina; Retinal; Retinal Pigments; Role; Shapes; Source; Staging; Study models; Time; Tissues; Trans-Activators; Variant; Vision; Visual; Visual system structure; Water; Weight; Work; base; chromophore; genetic variant; novel; public health relevance; research study; response; trait; transcription factor

DESCRIPTION (provided by applicant): The source of organismal diversity and the link between genotype and phenotype are key questions for understanding evolution. The evolutionary mechanisms that shape phenotypes depend on population size, the complexity of genetic networks underlying traits, and the relative role of genetics versus the environment in shaping traits. In this proposal, we examine the genetic basis of opsin gene expression, which determines visual sensitivities. We choose African cichlid fishes as they have significant variation in visual sensitivity. They also have small population sizes, comparable to humans, and will help identify the types of evolutionary mechanisms that might be important in small populations. African cichlid fishes have seven cone opsin genes, with species differing in which subsets of the genes are expressed. Typically, genes are expressed in three combinations, which we call the short, medium, and long visual palettes. To some degree, the optimal palette depends on the foraging style and the water clarity where species live. For the proposed work, we have made three crosses between species that differ in opsin palette: short x medium, short x long and medium x long. These three crosses will enable us to identify the key transcription factors that shift opsin expression between these genetically determined palettes. In addition, we will study two crosses that differ in whether environmental factors, such as light spectrum, contribute to opsin expression variation. By identifying factors which control both differences between the palettes and environmental plasticity, we can determine whether these two kinds of factors are the same or different. Further, we can use RNAseq from retinal and other transcriptomes to calculate the genetic network controlling opsin expression and see how these two types of factors are distributed in that network. We predict that factors controlling fixed genetic differences will be more central to the network, while factors involved in environmental responses will be more peripheral.

描述（由申请人提供）：生物多样性的来源以及基因型和表型之间的联系是理解进化的关键问题。塑造表型的进化机制取决于种群规模、性状背后遗传网络的复杂性，以及遗传与环境在塑造性状方面的相对作用。在这项提议中，我们研究了决定视觉敏感性的视蛋白基因表达的遗传基础。我们选择非洲丽鱼科鱼，因为它们的视觉敏感度存在显着差异。它们的种群规模也与人类相当，这将有助于确定对小种群可能重要的进化机制类型。非洲慈鲷有七个视锥细胞视蛋白基因，不同物种的基因子集表达情况不同。通常，基因以三种组合表达，我们称之为短、中、长视觉调色板。在某种程度上，最佳的调色板取决于物种的觅食方式和栖息地的水体透明度。对于拟议的工作，我们在视蛋白调色板不同的物种之间进行了三种杂交：短x中、短x长和中x长。这三个杂交将使我们能够识别在这些基因决定的调色板之间改变视蛋白表达的关键转录因子。此外，我们将研究两种杂交，它们的不同之处在于环境因素（例如光谱）是否会导致视蛋白表达变化。通过识别控制调色板之间差异和环境可塑性的因素，我们可以确定这两种因素是否相同或不同。此外，我们可以使用来自视网膜和其他转录组的 RNAseq 来计算控制视蛋白表达的遗传网络，并了解这两类因子在该网络中的分布情况。我们预测控制固定遗传差异的因素将在网络中更加核心，而涉及环境反应的因素将更加外围。