Integrated analysis of quantitative genetics and genomics to select genotypes of pacu (Piaractus mesopotamicus)

Abstract

The species Piaractus mesopotamicus (pacu) has occurrence in the basins of the Parana-Paraguay River and corresponds to one of the most fish produced in Brazilian aquaculture. Therefore, it is one of the main fish intended for breeding programs, especially because of its market acceptance (national and international). The objective of this project is to evaluate the performance of pacu families regarding the growth characteristics and resistance to Aeromonas hydrophila, and characterize QTLs (Quantitative Trait Locus) through gene mapping with SNPs (Single Nucleotide Polymorphisms). In total, 45 families of pacu will be done in the breeding program, which will be assessed the quantitative genetic parameters of five growth measurements (weight and four morphometric characteristics), and the survival rate of the bacterial challenge with Aeromonas hydrophila. In relation to the characterization of QTLs, 10 families of pacu will be selected for evaluation of each characteristic (growth and resistance). Then, sequencing/genotyping of SNPs will be performed by ddRAD-seq (double digest restriction site associated DNA sequencing), with the enzymes SphI and MluCI. In addition to the introduction of new genetic technologies for the aquaculture industry, the perspective is that the information of the SNPs will allow the construction of high density genetic maps, which will optimize the selection of superior genotypes for genetic improvement and increase the productivity of this important fish group. (AU)