【作者】 王军；

【导师】 杨官品；

【作者基本信息】 中国海洋大学 ， 生物化学与分子生物学， 2013， 博士

【摘要】 鲢(Hypophthalmichthys molitrix)和鳙鱼(Hypophthalmichthys nobilis)是我国特有的四大家鱼的两个重要成员，在我国淡水养殖业中占有重要的地位。但近年来，由于人口的增长和人类经济活动以及对于鲢鳙鱼不完善的遗传管理方法和使用方法等原因，使得这两种鱼的生长表现、抗病抗逆和遗传多样性都明显降低。随着分子生物学的快速发展，采用分子育种与传统育种相结合的方式选育性状优良品种，是保持鲢鳙养殖业健康发展与种质资源的可持续利用的有效途径。本研究以鲢鳙作为主要研究对象，构建了鲢鳙全微卫星标记的连锁图谱，并首次对鲢鳙杂交子代相关的11个形态性状进行了QTL定位分析，为推动鲢鳙分子遗传育种工作的开展奠定了基础。1.鲢鳙遗传连锁图谱的构建本研究采用拟测交策略，以捕捞自长江流域的野生鳙鱼（♀）和野生鲢鱼（♂）为父母本，通过人工授精产生的176个F1个体作为作图群体。采用包括实验室开发的各种来源的微卫星引物共882对，在群体中进行基因分型。筛选得到297个多态性标记，用于遗传连锁图谱的构建。构建鲢鳙性别平均连锁图谱，鲢雄性连锁图谱以及鳙雌性连锁图谱。鲢鳙性别平均连锁图谱共定位247个微卫星标记（其中15个标记为实验室自己开发的，但在之前研究中未定位到鲢鱼连锁图谱上的标记），这些标记分布于25个连锁群（包括2个三联体和2个连锁对）。图谱总长度1010.4cM,图谱覆盖率达81.0%。233个座位间最大间隔24.8cM，平均间隔4.4cM，连锁群长度1.2cM到67.5cM，平均每个连锁群长度40.4cM。每个连锁群标记数2到19个，平均每个连锁群上标记数为9.9个。鳙雌性连锁图谱共定位180个微卫星标记，分布于30个连锁群中（4个三联体9个连锁对）。图谱长度960.0cM,图谱覆盖率68.4%。148个座位间最大间隔为29.5cM，平均间隔6.4cM。各连锁群长度在1.2-108.1cM之间，平均连锁群长度为32.0cM。每个连锁去标记数从2-平均每个连锁群标记数为6.0个。鲢雄性连锁图谱共定位167个微卫星标记，分布于32个连锁群（5个三联体9个连锁对）。图谱长度为803.1cM，图谱覆盖率为66.4%。133个座位间最大间隔为30.6cM，平均间隔为5.9cM。各连锁群长度在2.3cM-99.9cM之间，连锁群平均长度25.1cM。每个连锁群标记数为2-11个，平均每个连锁群标记数为5.2个。2.鲢鳙相关形态性状的QTLs定位初步研究利用已经构建的鲢鳙性别平均连锁图谱，采用MapQTL5.0软件对，对鲢鳙杂种的体重、体长、体宽、体厚、头长、头高、腹棱长、胸鳍长、腹鳍长、尾鳍长和胸鳍到腹鳍之间的距离总共11个重要的形态性状进行了QTL定位分析，这11个表型相关系数均达到了极显著水平（P＜0.001），Person相关系数从0.950到0.996。该11个形态性状QTLs被定位到鲢鳙性别平均连锁图谱的总共6个连锁群上，每个形态性状定位QTL数目在1-6个之间，单个QTL的可释方差在9.1%到23.8%之间。研究发现许多性状QTL被定位到同一连锁群的同一位置，以连锁群19为例，11个形态性状的QTL都被在标记Hym435和Hym145之间区域内。另外如连锁群10和连锁群17，也各自定位了8个形态性状，而连锁群4、5、9,各自定位的性状数目为2-4。更多还原

【Abstract】 Silver carp (Hypophthalmichthys molitrix) and bighead carp(Hypophthalmichthys nobilis) are two of the four most important pond-cultured fishspecies, which occupies important status in freshwater aquaculture in China. InRecent years, due to many factors such as increase of human population, theintensification of economical activity, inappropriate broodstock management,continuous artificial propagation over a long period of time has caused tremendousdecrease of genetic diversity and degeneration of disease resistance and growthperformance.With the rapid development of molecular biology, it is an effectiveapproach to cultivating the good strains using the combination of molecular breedingand traditional breeding for the sustainable development of the two fishes fishery andutilization of germplasm resources. In this study, genetic linkage map and QTLmapping of11morphometric body measurements of silver carp and bighead wereconstructed using microsatellite DNA markers, which provides strong support forpromoting the application of molecular genetics and breeding of silver carp andbighead carp.1．Construction of linkage map for silver carp and bighead carpIn this study， a segregating population including176fingerling individualsfrom cross between a wild bighead carp (♀) and a silver carp（♂）collected from themain channel of Yangtze River was obtained based on the double pseudo-testcrossmapping strategy.882pairs of microsatellites primers used for genotyping includedthose developed ourselves and other sources.297pairs of polymorphismmicrosatellites primers was used to construct the different genetic linkage maps of silve carp and bighead carp: the sex average linkage map, the female (bighead carp)linkage map, the male (silver carp) linkage map.The sex average linkage map consisted of247microsatellites (15microsatellitesdeveloped ourselves but unmapped on the linkage map of silver carp we constructedearlier) assigned to25linkage groups (including2triplets and2doublets) thatspanned a length of1010.4cM, covering81.0%of the estimated genome size. Themaximum and average spaces between233loci were24.8cM and4.4cMrespectively. The length of linkage groups ranged from1.2cM to67.5cM with anaverage of40.4cM. The number of microsatellite markers per group varied from2to19with an average of9.9.The female (bighead carp)linkage map consisted of180microsatellites assignedto30linkage groups (including4triplets and9doublets) that spanned a length of960.0cM, covering68.4%of the estimated genome size. The maximum and averagespaces between148loci were29.5cM and6.4cM respectively. The length of linkagegroups ranged from1.2cM to108.1cM with an average of32.0cM. The number ofmicrosatellite markers per group varied from2to16with an average of6.0.The male (silver carp)linkage map consisted of167microsatellites assigned to32linkage groups (including5triplets and9doublets) that spanned a length of803.1cM, covering66.4%of the estimated genome size. The maximum and averagespaces between133loci were30.6cM and5.9cM respectively. The length of linkagegroups ranged from2.3cM to99.9cM with an average of25.1cM. The number ofmicrosatellite markers per group varied from2to11with an average of5.2.2. Quantitative trait loci for morphometric body measurements of the hybrids ofsilver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis)The location and effects of QTLs were estimated for body weight, standard length,body depth, body thickness, head length, head depth, length of ventral keel, length ofpectoral fin, length of pelvic fin, length of caudal fin, space between pectoral and pelvic fins traits using MapQTL5.0based on the sex average linkage map of silvercarp and bighead carp. Correlation coefficient of11phenotypic traits reached anextremely significant level. The Person coefficient was from0.950to0.996.11traitswere mapped at6QTLs on6linkage groups.The number of QTL of each trait rangedfrom1to6.The variance explained each locus ranged from9.1%to23.8%. It is alsovery interesting to note that many measurements were mapped on the same position;for example, a region bounded by Hym435and Hym145on linkage group19wasfound to be responsible for all the measurements analyzed in this study. Followinglinkage group19are linkage groups10and17, each contained QTL for8morphological characteristics. In addition, linkage groups4,5and9each were foundto hold QTL for2-4traits.更多还原