Identification of Growth-Associated Genes by Genome-Wide Association Study and Their Potential Application in the Breeding of Pacific White Shrimp (Litopenaeus vannamei)

The Pacific white shrimp (Litopenaeus vannamei) is the most widely cultured shrimp in the world. A great attention has been paid to improve its body weight (BW) at harvest through genetic selection for decades. Genome-wide association study (GWAS) is a tool to dissect the genetic basis of the traits. In this study, a GWAS approach was conducted to find genes related to BW through genotyping 94,113 single nucleotide polymorphisms (SNPs) in 200 individuals from a breeding population. Four BW-related SNPs located in LG19 and LG39 were identified. Through further candidate gene association analysis, the SNPs in two candidate genes, deoxycytidylate deaminase and non-receptor protein tyrosine kinase, were found to be related with the body weight of the shrimp. Marker-assisted best linear unbiased prediction (MA-BLUP) based on the SNPs in these two genes was used to estimate the breeding values, and the result showed that the highest prediction accuracy of MA-BLUP was increased by 9.4% than traditional BLUP. These results will provide useful information for the marker-assisted breeding in L. vannamei.