Gene expression profiles of Litopenaeus vannamei in response to carbonate alkalinity stress
Saline-alkali water-bodies are common in China. Alkalinity stress is considered to be one of the primary stressors for shrimp in saline-alkali water. Thus, an improved understanding of the molecular response to alkalinity stress is critical for advancing the sustainability of shrimp culture. Our objective was to evaluate the effect of carbonate alkalinity on global gene expression in Litopenaeus vannamei, a species of shrimp that is cultured throughout the world. We constructed two subtractive cDNA libraries from the gills of shrimp that were exposed to either 20 mmol/L alkalinity water or control water for 4 days. Dot blot expression analysis revealed that 158 clones were up-regulated and 291 clones were down-regulated following exposure to alkalinity stress. These clones were subsequently sequenced and up to 100 genes were identified from the forward and reverse libraries, of which 50 were well annotated. These differentially expressed genes were divided into a number of biological gene ontology groups related to catalytic activity, cell, structural molecule activity, binding, transporter activity, reproduction, enzyme regulator activity, and cellular process. Ion transportation genes, such as carbonic anhydrase (CA) and Na+-K+-ATPase (NKA-a), were up-regulated while immune response genes (e.g., lysozyme) were down-regulated. We evaluated expression of two differentially expressed genes (CA and NKA-a) in the gills and antennal gland of shrimp prior to exposure and following exposure to 20 mmol/L carbonate alkalinity water for 1-9 d. Exposure to carbonate alkalinity resulted in an increase in CA mRNA and NKA-a mRNA expression in the gills and antennal gland. The majority of the increase occurred on day 1. Our results suggest that expression of carbonic anhydrase and Na+-K+-ATPase genes plays an important role in the response to alkalinity stress in L. Vannamei, particularly in the gill and antennal gland. To our knowledge, this is the first study to use shrimp SSH cDNA libraries to detect global gene expression alterations in response to alkalinity stress. Alkalinity stress stimulated ion regulated processes and slowed down the gene expression related to immune system and reproduction in L. Vannamei. The alkalinity-regulated genes characterized in the present study may be convenient beginning points to study the molecular basis of alkalinity adaptation. The physiological role of these genes in environmental adaptation remains to be explored. Understanding how alkalinity triggers regulation of gene expression deserves further attention.
国家科技期刊平台
NSTL
万方数据
维普
