Linkage maps constructed with microsatellite markers for fish genetic improvement

我们在本研究中主要使用的微卫星标记：展望未来，很明显，一类特殊的核标记，称为短串联重复序列（STR或微卫星），可能会最大限度地提高大多数水生选择性育种计划的成本效益比。除了在目标物种的整个基因组中大量存在外，微卫星还表现出高水平的等位基因变异。这意味着微卫星提供更多的信息，每单位测定比其他标记系统。微卫星标记的范围：我们证实了范围的微卫星标记islated从虹鳟鱼或日本比目鱼。遗传连锁图谱的构建：（1）牙鲆遗传连锁图谱的构建利用111个微卫星标记和352个AFLP片段构建了第一张牙鲆遗传连锁图谱。不 关于我们 双亲的雄性连锁图谱由25个连锁群组成，雌性连锁图谱由27个连锁群组成，平均分辨率分别为8 cM和6.6cM。我们已经确定了96%的标记之间的连锁，总的图长估计为1000-1200 cM左右。(2)利用190个微卫星标记、3个RAPD标记、7个ESMP标记和7个等位酶标记，在3个回交家系中构建了虹鳟的遗传连锁图谱。该连锁图由29个连锁群组成，由于男性特异性的假连锁安排，女性地图中的潜在臂位移。雌性在端粒区域的重组率（0.41：1）比雄性低得多，而在靠近着丝粒的区域内的重组率在雌性中高得多（F：M = 10：1）。虹鳟鱼IPN疾病抗性的QTL分析：传染性胰腺坏死（IPN）是一种高度传染性的病毒性疾病，其导致鲑鱼过度死亡。我们绘制的虹鳟鱼遗传相似性图谱使鉴定控制抗病性等数量性状的单个基因座成为可能。以虹鳟抗虫品系RT-201和感虫品系RT-101为母本，通过回交分离群体定位了抗虫性的QTL。利用基于微卫星标记的框架图和Map Manager QT软件进行QTL分析。在A和C染色体上检测到两个影响抗病性的QTL（IPN R/S-1和IPN R/S-2），这表明这种特性在虹鳟鱼中是多基因的。这是首次在鱼类中发现与抗病性相关的QTL。少

Microsatellite markers that we mainly used in this study :Looking to the future, it is clear that a particular class of nuclear markers, referred to as short tandem repeats (STR or microsatellites), may maximize cost : benefit ratio for most aquatic selective breeding programs. Besides a large abundance throughout the genome of a target species, microsatellites exhibit high levels of allelic variation. This means that microsatellites confer more information per unit assay than other marker systems.Range capable of microsatellite markers :We confirmed the range capable of microsatellite markers islated from rainbow trout or Japanese flounder. As a result, microsatellite markers are able to be used in the level of genus, although all microsatellite markers not always fit to the tested fishes.Genetic linkage map :(1) Japanese flounderWe made the first genetic linkage map of the Japanese flounder Paralichthys olivaceus ) constructed with 111 microsatellite markers and 352 AFLP fragments. T … More he parental male linkage map consisted of 25 linkegae groups while the female map consisted of 27 groups, with an average resolution of 8 cM and 6.6 cM, respectively. We have identified linkage among 96 % of the markers and the total map length was estimated to be around 1000-1200 cM.(2) Rainbow troutWe constructed a genetic linkage map for a tetraploid derivative species, the rainbow trout (Oncorhynchus mykiss), using 190 microsatellite, 3 RAPD, 7 ESMP, and 7 allozyme markers in three backcross families. The linkage map consists of 29 linkage groups with potential arm displacements in the female map due to male-specific pseudolinkage arrangements. Females had much lower recombination rates (0.41:1) in telomeric regions than males, while recombination rates were much higher in females within regions proximal to the centromere (F:M = 10:1).QTL analysis for IPN disease resistance in rainbow trout :Infectious pancreatic necrosis (IPN) is a highly contagious viral disease which causes excessive mortality among salmonid fish. Rainbow trout genetic likage maps we constracted has made possible the identification of individual loci controlling quantitative traits such as disease resistance. We mapped quantitative trat loci (QTLs) for IPN resistance in a segregated polulation of backcross derived from out-crossing the resistant strain of rainbow trout, RT-201 and the susceptible one, RT-101.Phenotypic scores of 1-dead/susceptible and 0-survivor/resistant for QTL analysis were recorded from the results of artificially induced infection with IPNV. QTL analysis was carried out using a framework likage map based on microsatellite markers and a software, Map Manager QT. Two putative QTLs (IPN R/S-1 and -2) affecting disease resistance were detected on Chromosomes A and C designated by Sakamoto et al., suggesting that this trait is polygenic in rainbow trout. This is the first report of the identification of QTLs associated with disease resistance in fish. Less