不同产卵类型翘嘴鲌的地理分布格局及遗传关系研究

The spawning type of fish often has to some extent the species specificity. Culter alburnus is a kind of economic fish that distributed commonly in various rivers, lakes and reservoirs of China. Currently, the spawning type of C. alburnus displayed diversity in different geographical population (non-adhesive pelagic eggs, micro-adhesive pelagic eggs and adhesive demersal eggs). To explore whether C. alburnus have more diverse spawning types, and the genetic relationship between the population of different spawning types of C. alburnus, we conducted the study in the project including: (1) comprehensive and systematic investigation on the spawning types of C. alburnus in the major rivers, lakes and reservoirs of China, to obtain the geographical distribution pattern of spawning types of C. alburnus; (2) the typical ecological condition of C. alburnus which have different spawning types will be investgated to address the relationship between the ecotope and the spawning types; (3) the SSR and mitochondrial sequence (Cytb and D-Loop) will be explored to analysis the formation, genetic relationship and the phylogeny of different spawning types in C. alburnus. The overall purpose of the project is to provide reference for the research of the system classification and germplasm conservation of C. alburnus. The results also can be benefit for the study of formation mechanism of different spawning type in C. alburnus.

鱼类的产卵类型在某种程度上具有物种的特异性，翘嘴鲌是我国江河、湖泊和水库常见的经济鱼类，其不同地理种群呈现出产卵类型不同（产无粘性漂流性卵、微粘性漂流性卵和粘性沉性卵）的现象。为了探索翘嘴鲌是否存在更多样的产卵类型，不同产卵类型翘嘴鲌群体的遗传关系又是怎样，我们开展本项目研究，内容包括：（1）对我国主要江河、湖泊和水库翘嘴鲌的产卵类型进行调查，获得我国翘嘴鲌不同产卵类型的地理分布格局；（2）通过对不同产卵类型翘嘴鲌典型的生态环境进行调查和分析，探讨不同产卵类型翘嘴鲌的地理分布与生态环境间的关系；（3）采用SSR标记和线粒体Cytb和D-Loop序列分析不同产卵类型翘嘴鲌的发生、亲缘关系和系统演化。本项目的开展为翘嘴鲌的系统分类、种质保护提供参考，同时为翘嘴鲌不同类型卵的形成机制研究奠定基础。

鱼类产卵类型一般具有物种的特异性，可根据受精卵的结构特性区分鱼类科、属或种。翘嘴鲌（Culter alburnus）隶属于鲤科、鲌亚科、鲌属，属于我国多个湖泊水库天然名贵的经济鱼类，但不同地理种群翘嘴鲌的产卵类型出现了分化。本项目研究了典型翘嘴鲌地理种群的受精卵类型、遗传关系、漂流性卵和黏性卵的形态学差异及转录组差异。主要研究结果为：. （1）丹江口水库（湖北省）和兴凯湖（黑龙江省）翘嘴鲌的受精卵为漂流性卵，巢湖（安徽省）、梁子湖（湖北省）、鄱阳湖（江西省）和太湖（江苏省）翘嘴鲌的受精卵为黏性卵。. （2）利用SSR分子标记和线粒体D-loop序列分析了产漂流性卵翘嘴鲌群体（丹江口水库和兴凯湖）及黏性卵翘嘴鲌群体（巢湖、梁子湖、鄱阳湖和太湖）的遗传多样性。结果表明丹江口水库和兴凯湖翘嘴鲌群体（漂流性卵）间亲缘关系较近，巢湖、梁子湖、鄱阳湖和太湖翘嘴鲌群体（黏性卵）间亲缘关系较近。不同产卵类群未分化为亚种。翘嘴鲌群体整体遗传多样性较高，但相对来说兴凯湖翘嘴鲌群体遗传多样性较最低，需加强保护。. （3）可根据颜色及吸水后的卵周隙区分翘嘴鲌漂流性受精卵及黏性受精卵，黏性卵出膜时间显著长于漂流性卵。翘嘴鲌黏性卵膜厚度是和漂流性卵的4倍，漂流性卵和黏性卵差异基因主要参与生物学过程，细胞成分和分子功能，如溶酶体、激酶信号通路等，需进一步深入研究。. 本项目的实施，明确了典型翘嘴鲌地理种群的受精卵类型，产漂流性卵与产黏性卵翘嘴鲌地理种群的亲缘关系。为翘嘴鲌群体保护提供方向，为本单位国审品种的优化提供参考。同时聚焦漂流性卵与黏性卵的组织学与转录组学差异，探究更深层次的科学问题。