Transcriptomic response to low pH stress in gills of the pacific white shrimp,Litopenaeus vannamei

Abstract

The Pacific white shrimp, Litopenaeus vannamei, is a worldwide cultured crustacean species with important commercial value. pH decline caused by climate change, excess of uneaten food and excretions, as well as chemical pollution usually poses intense detrimental effects on the aquaculture industry L. vannamei. However, little information is available on the relative molecular mechanisms. In this study, we performed a comparative transcriptome analysis in the gills of L. vannamei between low‐pH challenged (pH = 6.8) and control (pH = 8.0) groups at soon after exposure to low pH (1 hr) and at a later stage (48 hr). A total of 83,673 nonredundant unigenes were generated. Among the two groups, the number of differentially expressed genes (DEGs) in group pH_6.8_1 hr versus pH_8.0_1 hr was 2,807, and that in group pH_6.8_48 hr versus pH_8.0_48 hr, there was 4,269 DEGs. The DEGs at 1 hr (pH_6.8_1 hr vs. pH_8.0_1 hr) and 48 hr (pH_6.8_48 hr vs. pH_8.0_48 hr) comparison groups are functionally annotated to integral components of membrane, phosphorylation, membrane, transport and other ion transfer‐related functions. At 1 hr, more DEG were extensively enriched into pathways related to signal transduction, infectious diseases, and cellular community, but at 48 hr, more DEGs were enriched into digestive system, biosynthesis of other secondary metabolites, transport, and catabolism and energy metabolism. Fifty‐seven potential DEGs previously reported to be associated with osmoregulation and acid–base balance were screened out. The present study provides valuable information on differential expression of L. vannamei genes at the stage soon after exposure to low pH and a later stage. In addition, the large number of transcripts with regard to ion regulation obtained in this study provides a strong basis to study pH regulation in shrimp.