Transcriptome Analysis of the Hepatopancreas in the Litopenaeus vannamei Responding to the Lead Stress.

Lead (Pb) is one of the most hazardous pollutants and toxic heavy metal in marine environment. The molecular mechanisms of Pb toxicity in aquatic organism are not well understood. In this study, hepatopancreas transcriptome of Litopenaeus vannamei (L. vannamei) was characterized by a comparison between control and Pb exposure samples using RNA-Seq approach. Hepatopancreas morphology of L. vannamei was also assessed. The result reveals that compared with the control group, an increase in the number of B cells was observed following Pb exposure in L. vannamei. Transcriptome data showed that a total of 1593 genes were recognized to be differentially expressed including 1278 up-regulated and 315 down-regulated genes. These genes were mainly associated with energy metabolism, cell apoptosis, exogenous microbial infection, cell junction, and cell adhesion. Fifteen ribosomal protein genes (RPS3, RPS13, RPSA, RPL11, RPS2, RPL8, RPS23, RPL3, RPL5, RPS6, RPS4X, RPS18, RPL19, RPL9, RPL6) were identified as the common hubs of protein-protein interaction (PPI) networks, as well as part of modules of the PPI network. Besides ribosomal protein, we identified differential expression genes (DEGs) including GAPDH, EEF1A1, HSPA8, UBC, and EEF1G as the common hubs of PPI networks. These findings may have important implications for understanding the adverse biological effects of Pb and its toxic mechanisms, as yet not clearly defined, and provide potential biomarkers of Pb exposure in hepatopancreas of L. vannamei, which might be useful for monitoring aquatic environments and assessing the health of the marine ecosystem.