Identification of candidate genes associated with resistance against Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease in Litopenaeus vannamei via bulked segregant analysis.

Acute hepatopancreatic necrosis disease (AHPND), a predominant bacterial affliction in the cultivation of the Pacific white shrimp Litopenaeus vannamei, is triggered by Vibrio parahaemolyticus (Vp). In the present study, two populations of L. vannamei were used to construct a full-sib family aimed at identifying SNPs and genes associated with resistance to Vp. Through whole-genome resequencing and bulked segregant analysis, 57 scaffolds were monitored via SNP and INDEL data, respectively, including 215 annotated genes enriched in the MAPK and FoXO pathways and other immune-related pathways. Among these, two scaffolds (Scaffold_1573 and 1504) containing 22 annotated genes with nonsynonymous mutations were both screened out on the basis of the SNP and InDel data. A key immune-related gene, LvPLP1, was identified, and its antibacterial function was further confirmed through dsRNA interference under Vp challenge. Consequently, the mortality of shrimp and Vibrio loads in the hepatopancreas significantly increased under dsRNA interference with LvPLP1 during Vp challenge, suggesting that the LvPLP1 gene is a key functional gene involved in anti-Vp infection in L. vannamei. This study identified functional genes underlying resistance to Vp infection and laid a genetic foundation for marker-assisted selection of L. vannamei shrimp resistant to Vp.