Gutierrez Alejandro P, Yáñez José M, Fukui Steve, Swift Bruce, Davidson William S
Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
Faculty of Veterinary and Animal Sciences, University of Chile, Santiago, Chile.
PLoS One. 2015 Mar 10;10(3):e0119730. doi: 10.1371/journal.pone.0119730. eCollection 2015.
Early sexual maturation is considered a serious drawback for Atlantic salmon aquaculture as it retards growth, increases production times and affects flesh quality. Although both growth and sexual maturation are thought to be complex processes controlled by several genetic and environmental factors, selection for these traits has been continuously accomplished since the beginning of Atlantic salmon selective breeding programs. In this genome-wide association study (GWAS) we used a 6.5K single-nucleotide polymorphism (SNP) array to genotype ∼ 480 individuals from the Cermaq Canada broodstock program and search for SNPs associated with growth and age at sexual maturation. Using a mixed model approach we identified markers showing a significant association with growth, grilsing (early sexual maturation) and late sexual maturation. The most significant associations were found for grilsing, with markers located in Ssa10, Ssa02, Ssa13, Ssa25 and Ssa12, and for late maturation with markers located in Ssa28, Ssa01 and Ssa21. A lower level of association was detected with growth on Ssa13. Candidate genes, which were linked to these genetic markers, were identified and some of them show a direct relationship with developmental processes, especially for those in association with sexual maturation. However, the relatively low power to detect genetic markers associated with growth (days to 5 kg) in this GWAS indicates the need to use a higher density SNP array in order to overcome the low levels of linkage disequilibrium observed in Atlantic salmon before the information can be incorporated into a selective breeding program.
早熟被认为是大西洋鲑鱼养殖的一个严重缺陷，因为它会阻碍生长、延长生产时间并影响鱼肉品质。尽管生长和性成熟都被认为是由多种遗传和环境因素控制的复杂过程，但自大西洋鲑鱼选择性育种计划开始以来，一直在对这些性状进行选择。在这项全基因组关联研究（GWAS）中，我们使用了一个6.5K单核苷酸多态性（SNP）阵列对来自加拿大Cermaq亲鱼计划的约480个个体进行基因分型，并寻找与性成熟时的生长和年龄相关的SNP。使用混合模型方法，我们鉴定出了与生长、早成熟（早熟）和晚成熟显著相关的标记。在早成熟方面发现了最显著的关联，相关标记位于Ssa10、Ssa02、Ssa13、Ssa25和Ssa12上；在晚成熟方面，相关标记位于Ssa28、Ssa01和Ssa21上。在Ssa13上检测到与生长的关联程度较低。鉴定出了与这些遗传标记相关的候选基因，其中一些与发育过程有直接关系，特别是那些与性成熟相关的基因。然而，在这项GWAS中检测与生长（达到5千克的天数）相关的遗传标记的能力相对较低，这表明需要使用更高密度的SNP阵列，以便在将信息纳入选择性育种计划之前克服在大西洋鲑鱼中观察到的低连锁不平衡水平。
