水产养殖动物遗传连锁图谱及QTL定位研究进展

自1997年美国农业部启动5种水产养殖动物基因组计划以来，在不到10年的时间里，世界各国都相继开展了本国主要水产养殖动物基因组研究。截至2005年底，有近17种海淡水养殖动物公布了遗传连锁图谱：属于高密度连锁图谱的有虹鳟和大西洋鲑（标记数超过1000）；属于中密度遗传连锁图谱的有罗非鱼、沟鲶、黑虎虾、日本牙鲆和欧洲海鲈（标记数为400-1000）；属于低密度遗传连锁图谱的有泰国的胡鲶，中国的栉孔扇贝、鲤鱼，日本的黄尾鲕，美国的牡蛎等近10种养殖种类（标记数少于400）。水产养殖动物遗传连锁图谱的构建和发展，促进了一些与经济性状（如生长、抗逆、发育等）相关的数量性状位点（QTL）的定位研究。然而，QTL定位研究目前只在具有中高密度遗传连锁图谱的鲑科鱼类（虹鳟、大西洋鲑和北极嘉鱼）、罗非鱼、沟鲶和日本牙鲆等种类中开展，而且定位研究仍处在初级水平。遗传连锁图谱的高分辨率和QTL在图谱上的精确定位，是今后能否实现对主要水产养殖动物的经济性状进行遗传操作的技术保证，同时也是实现分子标记或基因辅助育种在水产养殖动物中成功运用的制胜法宝。

Advancements in Genetic Linkage Maps and Quantitative Trait Locations of Aquatic Farming Animals

Many countries have launched genomic studies for aquatic farming animals since the Agriculture Ministry of America initiated genomic studies for five kinds of aquatic farming animals in 1997. At the end of 2005, genetic linkage maps of approximately 17 briny or limnetic farming animals have been published. Of these 17 species, the rainbow trout and the Atlantic salmon have high-density linkage maps with over 1 000 markers; the tilapia, the channel catfish, the black tiger shrimp, the Japanese flounder and the European sea bass have middle-density linkage maps with 400-1 000 markers; the remaining 10 species, including the Thailand walking catfish, the Chinese Zhikong scallop, the common carp, the Japanese yellowtail amberjack and the American oyster, have low-density linkage maps with less than 400 markers. The framework and development of genetic linkage maps of aquatic farming animals facilitated QTL mapping associated with interesting economic traits, such as growth, resistance and development. However, QTL mapping was only studied preliminarily in a few species with middle or high density linkage maps, such as salmonids (the rainbow trout, the Atlantic salmon and the Arctic char), the tilapia, the channel catfish and the Japanese flounder. Genetic linkage maps with higher resolution and fine QTLs mapping are the keys to implementing genetic technology in interesting economic traits and also have the power to successfully carry out molecular marker or gene assistant selection breeding in aquatic farming animals.