Genomic predictions for resistance to Aeromonas hydrophila in pacu Piaractus mesopotamicus

• Grant number: 22/11129-3
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: October 28, 2022
• End date: February 27, 2023
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Diogo Teruo Hashimoto
• Grantee: Shisley Cristina da Silva Manso
• Supervisor: José Manuel Yáñez
• Host Institution: Centro de Aquicultura (CAUNESP). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Institution abroad: Universidad de Chile, Chile
• Associated to the scholarship: 21/14869-5 - Genomic predictions for Aeromonas hydrophila resistance in pacu Piaractus mesopotamicus, BP.MS

Abstract

Pacu Piaractus mesopotamicus is one of the most important native fish cultivated in South America. Aeromonas hydrophila is a free-living gram-negative bacterium responsible for large economic losses in its production. Studies on the genetic basis of resistance of farmed pacu to A. hydrophila infection have revealed a polygenic architecture of resistance. In the case of polygenic traits, genomic selection can significantly improve the selection accuracy of breeding values compared to traditional selection, and therefore enhance the response of selection for resistance to A. hydrophila infection in pacu. The aim of this study is to assess genomic prediction ability using a low-cost strategy that combines a low-density SNP array and genomic imputation. Genomic DNA from fifty pacu families of a breeding nucleus from the Aquaculture Center of Unesp (CAUNESP/UNESP - Brazil) has been used for this purpose. A medium-density SNP array (multispecies Axiom SerraSNP) with approximately ~20K SNPs, and a low-density (AgriSeq tGBS) SNP array with 1091 SNPs were previously constructed as a resource for genomic selection of pacu. The low-density SNP array will be optimized by genotype imputation. Genotype imputation will be assessed by combining parental genotypes obtained via the medium-density array with progeny genotypes from the low-density SNP array (1K SNPs). High imputation and genomic prediction accuracy suggest that the imputation of genotypes from low-density to mediumdensity SNP arrays of pacu could be an economically viable strategy for the development of genomic selection for pacu, with great utility for application in the selection of superior genotypes of pacu resistant to A. hydrophila, thus increasing its production. (AU)