Epistasis: Its role in complex traits and speciation

上位性：其在复杂性状和物种形成中的作用

• 批准号: 6742416
• 负责人: Michael J Wade
• 金额: $ 31.5万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6742416
• 关键词: Coleoptera; fertility; gene expression; gene interaction; genetic library; genetic mapping; genetic polymorphism; genetic recombination; genetic regulation; genetic strain; inbreeding; male reproductive system disorder; mathematical model; phenotype; population genetics; quantitative trait loci; species difference

DESCRIPTION (provided by applicant): Our goal is to better understand the role of gene interactions (epistasis) in producing complex phenotypes using a combination of theoretical models, quantitative genetics, molecular genetics, and experimental populations of flour beetles, genus Tribolium. Our specific goals are to isolate, map, and compare the genes that interact to cause a reduction of mating success, viability, and fertility in (1) inter-population crosses, with those causing fitness reduction in (2) inter-specific crosses. Incompatibility genes interact in the same way as those genes causing human genetic diseases, cancer susceptibility, and pathogen resistance. First, we will investigate the genetic basis of (1) pre-zygotic male infertility; and, (2) post-zygotic reproductive isolation observed in inter-population crosses of T. castaneum. Our statistical genetic studies indicate that maternal effects and epistasis cause reduced viability and fertility fitness in F2 and backcrosses between 3 pairs of populations from collected from Central America, South America, and Africa. However, because statistical genetic methods average positive and negative effects of different gene combinations, we will use a microsatellite map of the Tribolium genome to dissect the average effects of gene interactions into their single locus components. Because each of 3 pairs of partially isolated populations is fully inter-fertile with a laboratory strain, we will create recombinant congenic lines by reciprocal backcrosses to the lab strain in order to isolate those genes in each of the two backgrounds, which, when combined-by inter-population crosses, cause reproductive incompatibility. Second. we will identify the genes in T. castaneum, which interact with one another and with genes from T. freemani, to cause hybrid male deformities and hybrid male inviability in inter-specific crosses. We will compare the sets of genes reducing fitness in inter-population crosses in T. castaneum with those diminishing the fitness of its inter-specific hybrids with T. freemani. We can determine whether the genes interacting to reduce the fitness of T. castaneum inter-population crosses are a subset of those reducing hybrid fitness in inter-specific crosses. The latter must include some gene differences accumulated after speciation. Alternatively, the barrier to gene exchange between T. castaneum and T. freemani may represent either, a sample of the genes posing incipient barriers, to gene exchange between populations of T. castaneum, or it may be unique.

描述（由申请人提供）：我们的目标是更好地了解基因相互作用（上位性）在产生复杂表型中的作用，使用理论模型，数量遗传学，分子遗传学和实验种群的面粉甲虫，拟谷盗属。我们的具体目标是分离，映射和比较相互作用导致交配成功率，生存能力和生育力降低的基因（1）种群间杂交，与那些导致适应度降低的基因（2）种间杂交。不相容基因的相互作用方式与导致人类遗传疾病、癌症易感性和病原体抗性的基因相同。首先，我们将研究（1）合子前雄性不育的遗传基础，和（2）合子后生殖隔离观察在种群间杂交的T。栗色。我们的统计遗传研究表明，母体效应和上位性导致F2和来自中美洲、南美洲和非洲的3对群体之间的回交的生存力和育性适合度降低。然而，由于统计遗传学方法平均不同基因组合的积极和消极的影响，我们将使用赤拟谷盗基因组的微卫星图谱解剖基因相互作用的平均影响到他们的单位点组件。因为3对部分分离的群体中的每一对都与实验室菌株完全互育，所以我们将通过与实验室菌株的相互回交来创建重组同源系，以便分离两种背景中的每一种中的那些基因，当通过群体间杂交组合时，这些基因会导致生殖不亲和性。一下我们将在T. castaneum，它们彼此相互作用，并与T. freemani，在种间杂交中引起杂种雄性畸形和杂种雄性不育。我们将比较T. castaneum与T.弗里曼尼我们可以确定是否基因相互作用，以减少适应性的T。栗树种群间杂交是在种间杂交中降低杂种适合度的那些杂交的子集。后者必须包括物种形成后积累的一些基因差异。另外，T. castaneum和T. freemani可能代表了T.或者它可能是独一无二的。