银鲫核质基因多态性与性别进化关联分析

Carassius auratus complex composed of triploid gibel carp and diploid crucian carp widely distribute in the natural hatcheries all over China. Recently gibel carp has become a model fish in reproduction and evolution research own to its unique dual modes of gynogenesis and sexual reproduction, ployploidy origin and high clonal diversities.At the same time, gibel carp is one of the most important cultivated conventional freshwater varieties. In comparison with other gynogenetic vertebrate species that are all composed of unisexual females, there existed significant portion of male individuals in natural habitats and they may contribute to evolution and maintance of high clonal diversities. This study aimed to maintain the transferrin alleles，mitochondrial DNA haplotype and AFLP scan patterns of identified gibel carp clones and control diploid crucian carp using nucleo-cytoplasmic markers. Further analysis of gibel carp origin and evolution were carried out based on geographic divergence and high genetic diversity. Sex evolution also processed according to the differentiation between male and female populations. Based the above issues, we hope to deep into the relationships among nucleo-cytoplasmic genes evolution, reproduction model diversity and clonal diversity, which will benefit the future breeding application.

三倍体银鲫和二倍体鲫组成的鲫鱼复合体在我国大部分天然群体中广泛存在。因为多倍化起源、独特的单性和有性双重生殖方式以及高度的克隆多样性等特点，银鲫已经成为生殖和进化研究重要的模式鱼类，也是我国重要的大宗淡水养殖鱼类之一。与其它单性物种由全雌性个体组成不同的是，在全国大部分群体中都检测到一定比例的银鲫雄性个体，因此雄性个体可能在银鲫进化和维持高度克隆多样性过程中发挥了重要作用。本项目以经转铁蛋白电泳初步分型的银鲫克隆系及部分二倍体鲫作为实验材料，利用细胞核和细胞质重要分子标记，在全部克隆系中进行转铁蛋白等位基因和线粒体DNA单倍型鉴定以及AFLP全基因组扫描。在进行遗传变异分布分析的基础上，进行银鲫起源进化分析，同时通过雌雄群体差异分析初步探讨银鲫性别进化，进行雄性个体比例与遗传多样性之间的关联分析，并试图阐明核质基因多样性、性别进化以及克隆多样性之间的相互关系，为鲫鱼遗传育种提供理论依据。

三倍体银鲫和二倍体鲫组成的鲫鱼复合体在我国大部分天然群体中广泛存在。因为多倍化起源、独特的单性和有性双重生殖方式以及高度的克隆多样性等特点，银鲫已经成为生殖和进化研究重要的模式鱼类，也是我国重要的大宗淡水养殖鱼类之一。本项目以经转铁蛋白电泳初步分型的银鲫克隆系及部分二倍体鲫作为实验材料，在全国采集的3105尾个体中进行转铁蛋白等位基因和线粒体DNA单倍型鉴定，进行银鲫起源进化分析，并对选育新品种异育银鲫“中科5号”进行了遗传鉴定。另外在异育银鲫“中科3号”新品种繁殖后代中鉴定到异源多倍体，利用核质分子标记进行了遗传鉴定和形成机制研究。本项目研究分析了我国鲫复合体的遗传多样性，鉴定了多个银鲫克隆系，为银鲫遗传育种提供了重要的种质资源。另外阐明了银鲫起源进化机制，具有重要的理论意义。本项目合成的异源多倍体为银鲫多倍体育种提供了重要的技术路线，另外选育了一个银鲫新品种异育银鲫“中科5号”，具有重大的推广应用价值。