Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain.
Anim Genet. 2013 Apr;44(2):149-57. doi: 10.1111/j.1365-2052.2012.02385.x. Epub 2012 Jun 13.
Disease resistance-related traits have received increasing importance in aquaculture breeding programs worldwide. Currently, genomic information offers new possibilities in breeding to address the improvement of this kind of traits. The turbot is one of the most promising European aquaculture species, and Philasterides dicentrarchi is a scuticociliate parasite causing fatal disease in farmed turbot. An appealing approach to fight against disease is to achieve a more robust broodstock, which could prevent or diminish the devastating effects of scuticociliatosis on farmed individuals. In the present study, a genome scan for quantitative trait loci (QTL) affecting resistance and survival time to P. dicentrarchi in four turbot families was carried out. The objectives were to identify QTL using different statistical approaches [linear regression (LR) and maximum likelihood (ML)] and to locate significantly associated markers for their application in genetic breeding strategies. Several genomic regions controlling resistance and survival time to P. dicentrarchi were detected. When analyzing each family separately, significant QTL for resistance were identified by the LR method in two linkage groups (LG1 and LG9) and for survival time in LG1, while the ML methodology identified QTL for resistance in LG9 and LG23 and for survival time in LG6 and LG23. The analysis of the total data set identified an additional significant QTL for resistance and survival time in LG3 with the LR method. Significant association between disease resistance-related traits and genotypes was detected for several markers, a single one explaining up to 22% of the phenotypic variance. Obtained results will be essential to identify candidate genes for resistance and to apply them in marker-assisted selection programs to improve turbot production.
疾病抗性相关特征在全球水产养殖育种计划中受到越来越多的重视。目前，基因组信息为育种提供了新的可能性，以解决这类特征的改良问题。大菱鲆是最有前途的欧洲水产养殖物种之一，而 Philasterides dicentrarchi 是一种引起养殖大菱鲆致命疾病的盾纤毛虫寄生虫。对抗疾病的一种有吸引力的方法是获得更健壮的亲鱼，这可以预防或减轻盾纤毛虫病对养殖个体的破坏性影响。在本研究中，对四个大菱鲆家系中影响对 P. dicentrarchi 的抗性和存活时间的数量性状位点 (QTL) 进行了基因组扫描。目的是使用不同的统计方法[线性回归 (LR) 和最大似然 (ML)] 识别 QTL，并定位与它们在遗传育种策略中的应用相关的显著关联标记。检测到控制对 P. dicentrarchi 的抗性和存活时间的几个基因组区域。当分别分析每个家系时，LR 方法在两个连锁群 (LG1 和 LG9) 中鉴定出与抗性相关的显著 QTL，而 ML 方法则在 LG9 和 LG23 中鉴定出与抗性相关的 QTL，在 LG6 和 LG23 中鉴定出与存活时间相关的 QTL。总数据集的分析用 LR 方法在 LG3 中鉴定出另一个与抗性和存活时间相关的显著 QTL。在几个标记与疾病抗性相关特征之间检测到显著的关联，其中一个标记解释了高达 22%的表型方差。获得的结果对于鉴定抗性候选基因以及应用于标记辅助选择计划以提高大菱鲆产量至关重要。
