Effect of temperature on antioxidant enzyme gene expression and stress protein response in white shrimp, Litopenaeus vannamei

The white shrimp Litopenaeus vannamei is one of the most important economic species in shrimp farming and are frequently exposed to multiple stressors (including temperature) in aquaculture. The differential expression of seven genes encoding antioxidant enzymes and stressor biomarkers was investigated by real-time quantitative PCR in haemocytes and hepatopancreas and gill extracted from L. vannamei following acute temperature stress. Temperature stress induced CAT, GST, ferritin and HSP60 gene expression in gills. Western blot results also revealed that HSP60 was induced in the same tissue after acute temperature stress. Heat stress resulted in an increase in most examined genes in haemocytes (excluding HSP60) suggesting haemocytes may be an early response tissue in acute temperature stress. GST was significantly up-regulated in haemocytes (to up to 16.4 fold at 22 °C and 71.8 fold at 28 °C, respectively) during exposure to heat stress. In addition, MnSOD was more strongly induced in haemocytes and hepatopancreas (to up to 273.8 fold and 115.8 fold, respectively) after exposure to 28 °C from 15 °C implying their important role in antioxidant protection in response to heat stress. The transcriptional responses of these genes to temperature stress will provide the basis for a multi-biomarker system that could be used for the biomonitoring of aquatic environments.