Genomics Study of the Exposure Effect of Gymnodinium catenatum, a Paralyzing Toxin Producer, on Crassostrea gigas Defense System and Detoxification GenesReport as inadecuate




Genomics Study of the Exposure Effect of Gymnodinium catenatum, a Paralyzing Toxin Producer, on Crassostrea gigas Defense System and Detoxification Genes - Download this document for free, or read online. Document in PDF available to download.

Background

Crassostrea gigas accumulates paralytic shellfish toxins PST associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response.

Principal Findings

We found that 24 h feeding on toxic dinoflagellate cells acute exposure induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense copper-zinc superoxide dismutase, Cu-Zn-SOD, cell detoxification glutathione S-transferase, GST and cytochrome P450, CPY450, intermediate immune response activation lipopolysaccharide and beta glucan binding protein, LGBP, and stress responses glutamine synthetase, GS in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days 30×103 cells mL−1 showed higher gene expression levels. A significant increase was observed in Cu-Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum 3×103 cells mL−1 produced a significant increase on the transcription level than in a mixed diet 3×103 cells mL−1 of G. catenatum+0.75×106 cells mL−1 I. galbana in all the analyzed genes.

Conclusions

Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to stress generated by toxic dinoflagellate exposure.



Author: Norma García-Lagunas, Reyna Romero-Geraldo, Norma Y. Hernández-Saavedra

Source: http://plos.srce.hr/



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