Abstract
Background: In recent years, the disease outbreak caused by Vibrio harveyi upset the booming development of the Chinese tongue sole (Cynoglossus semilaevis) farming industry. Genomic selection (GS) is a powerful method to improve the traits of interest, which has been proved in livestock and some fishes. Besides, the single nucleotide polymorphism (SNP) array is an efficient genotyping platform that can be used for genetic studies. To improve V. harveyi resistance in C. semilaevis, we firstly constructed a reference group of 1,572 individuals and investigated accuracies of four genomic methods (genomic best linear unbiased prediction (GBLUP), weighted GBLUP, BayesB, and BayesC) at predicting the genomic estimated breeding value (GEBV) using five-fold cross-validation and SNPs varying from 0.5 k to 500 k. Then, an SNP array was developed using the Affymetrix Axiom technology, and its accuracy in genotyping was evaluated by comparing SNPs generated by the array and by the re-sequencing technology. Finally, we selected 44 candidates as the parents of 23 families of C. semilaevis to evaluate the feasibility of the SNP array for GS.Results: all genomic methods outperformed the pedigree-based BLUP (ABLUP) when at least 50 k SNPs used for prediction, of which GBLUP resulted in better estimation than ABLUP when more than 1 k SNPs used. A 38 k SNP array, “Solechip No.1”, was developed with an average of 10.5 kb inter-spacing between two adjacent SNPs. The SNPs generated by the array and by the re-sequencing reached an average consistency of 94.8 %, of which 79.3 % of loci had a more than 90 % of the consistency. The survival rates of these 23 offspring families had a correlation of 0.706 with the family GEBVs (mid-parental GEBVs), and the average survival rate of the top five families in GEBVs (79.1 %) is higher than the bottom five families (58.1 %).Conclusion: GS is an efficient method to improve the V. harveyi resistance in C. semilaevis, and the SNP array “Solechip No.1” is a convenient and reliable tool for the Chinses tongue sole selective breeding practice.
Fish disease monitoring along a pollution transect: a case study using dab Limanda limanda in the German Bight
