Expression profile of eight glutathione S-transferase genes in Crassostrea ariakensis after exposure to DSP toxins producing dinoflagellate Prorocentrum lima

In this study, changes in eight GSTs mRNA level including GST-alpha, GST-sigma, GST-omega, GST-pi, GST-mu, GST-rho, GST-theta and microsomal GST (mGST) in the oyster Crassostrea ariakensis after exposure to Prorocentrum lima have been evaluated by quantitative real-time PCR. Additionally, the contents of five GST isoforms were detected by ELISA. After exposure to P. lima at density of 2 x 10(5) cells/L, mGST mRNA significantly increased in gill, while GST-sigma was induced in digestive gland. After exposure to P. lima at density of 2 x 10(6) cells/L, GST-omega and mGST expressions increased in gill, whereas GST-alpha and GST-sigma were induced in digestive gland. The GST content and activity in oysters exposed to P. lima also showed a different pattern when the different isoforms and organs were compared. After exposure to P. lima (2 x 10(6) cell/L), GST-pi increased in gill but decreased in digestive gland. The total GST enzyme activity increased in gill, while remained unchanged in digestive gland. These various regulation of GST gene expressions indicated that the GSTs isoenzymes might play divergent physiological roles in the detoxification of DSP toxins in C. ariakensis. (C) 2015 Elsevier Ltd. All rights reserved.