Whole-Genome Resequencing Reveals Selection Signals Associated with Vibrio parahaemolyticus Stress Tolerance in...

Acute hepatopancreatic necrosis disease (AHPND) is a fatal disease caused by Vibrio parahaemolyticus, which severely impacts the crustacean aquaculture industry. In this study, we focused on the economically important Portunus trituberculatus, and investigated the differences in disease resistance among domesticated populations and its genetic basis using artificial infection experiments and resequencing analysis. A 12-day V. parahaemolyticus (5.6 × 10⁶ CFU/mL) challenge experiment involving 1,000 crabs identified a subset of highly resistant individuals. Whole-genome resequencing of the high-resistant and normal populations generated a total of 1,261 Gb of sequencing data, achieving an average depth of 14.43×. Population structure and selective sweep analyses identified 96 candidate regions and 244 candidate genes, including Serpin B1 and Croquemort. KEGG enrichment analysis revealed that the candidate genes were significantly enriched in signaling pathways related to bacterial infections, including Salmonella infections, bacterial invasion of epithelial cells and phagolysosomes. Notably, genes from the actin family emerged as central components within these pathways, suggesting their pivotal role in mediating immune responses in the highly resistant population. These findings provide exploratory genomic evidence and candidate resources for future functional validation and disease-resistant breeding.