Analysis of differential gene expression in Litopenaeus vannamei under High salinity stress

Litopenaeus vannamei has a salinity tolerance range of 0.5-78 ppt. In China, cultivation of L. vannamei in high salinity waters in the Circum-Bohai Region resulted in low survival rates and yields because high salinity has toxic effects on shrimp. Thus, identifying differential gene expression in different tissues of L. vannamei under high salinity stress would help revealing its salt tolerance mechanisms. In the present study, L. vannamei was cultivated under two salinity levels (34 and 58 ppt) for 90 days. Gill, muscle, and hepatopancreatic tissues were then extracted from the shrimp for transcriptome sequencing and quantitative real-time PCR, to analyze the differential expression of genes at the transcriptome level. The 1659 significantly differentially expressed genes comprised 436, 318, and 364 upregulated genes and 428, 317, and 156 downregulated genes in gill, hepatopancreatic, and muscle tissues, respectively. Higher differential expression was found in genes related to osmoregulation, ion transport, and antioxidation in gill tissue; immune defense, bacterial lysis, and apoptosis in hepatopancreatic tissue; and development and nutrient metabolism in muscle tissue. The results of this study can enrich the basic knowledge of shrimp stress biology, and provide reference for understanding the molecular mechanism of shrimp salt tolerance.