Genome Scan for Genomic Regions and Genes Associated with Growth Trait in Pacific White Shrimp Litopeneaus vannamei

The Pacific white shrimp Litopeneaus vannmei (L. vannmei) is a predominant aquaculture shrimp species worldwide, and it is considered as the aquaculture species with the highest single output value. Advances in selective breeding have accelerated the development of L. vannmei aquaculture. Recently, the genome-wide association studies (GWAS) have been applied in aquaculture animals and markers associated with economic traits were identified. In this study, we focused on the growth trait of L. vannamei and performed GWAS to identify SNPs or genes associated with growth. Genomic regions in linkage group 7, 27, 33, and 38 were identified to be associated with body weight and body length of the shrimp. Further, candidate gene association analysis was performed in two independent populations and the result demonstrated that the SNPs in the genes protein kinase C delta type and ras-related protein Rap-2a were significantly associated with the growth trait of L. vannamei. This study showed that GWAS analysis is an efficient approach for screening trait-related markers or genes. The genomic regions and genes identified in this study are essential for further fine mapping of growth-related genes. The identified markers will provide useful information for marker-assisted selection in L. vannamei.