Expressions of oxidative stress-related genes and antioxidant enzyme activities in Mytilus galloprovincialis (Bivalvia, Mollusca) exposed to hypoxia

Abstract

Background: In this study, we investigated transcription and enzyme level responses of mussels Mytilus galloprovincialis exposed to hypoxic conditions. Genes for catalase (CAT), cytochrome P450, glutathione Stransferase (GST), metallothionein, superoxide dismutase (SOD), cytochrome c oxidase subunit 1 (COX-1), and NADH dehydrogenase subunit 2 were selected for study. Transcriptional changes were investigated in mussels exposed to hypoxia for 24 and 48 h and were compared to changes in control mussels maintained at normal oxygen levels. Activities of CAT, GST, and SOD enzymes, and lipid peroxidation (LPO) were also investigated in mussels following exposure to hypoxia for 24, 48, and 72 h. Results: Relative to the control group, the CAT activity decreased in all hypoxia treatments, while the activity of GST significantly increased in mussels exposed to hypoxia for 24 and 48 h, but decreased in those exposed for 72 h. The LPO levels were significantly higher in mussels in the 24-and 48-h hypoxia treatments than those in the control mussels, but there was no significant change in the SOD activities among all hypoxia treatments. Messenger RNA levels for the CAT, cytochrome P450, GST, metallothionein, and SOD genes were not significantly affected by hypoxic conditions for 48 h, but the expressions of the COX-1 and NADH dehydrogenase subunit 2 genes were significantly repressed in mussels in both the 24-and 48-h exposure treatments.

A First Insight into the Genome of the Filter-Feeder Mussel Mytilus galloprovincialis

“…These genes had functions related to toll-like receptor signalling pathway, inflammatory response, regulation of innate immune response, and defence response to fungus, virus and bacteria. Second, other genes important for adaptation in mussels are genes that confer resistance to hypoxia and oxidative stress during tidal emersion and resubmersion cycles [ 96 , 97 ]. We found seven genes annotated with the GO term “resistance to hypoxia” (GO:0001666), such as isocitrate dehydrogenase [ 98 ] and ubiquitin carboxyl-terminal hydrolase [ 99 ] genes.…”

The trout farm effect on Dinocras megacephala (Plecoptera: Perlidae) larvae: Antioxidative defense

“…Water eutrophication caused hypoxia, which is one of the most frequent and serious of environmental problems. Published data confirm that hypoxic stress correlates with modification of antioxidative enzyme activities and with transcriptional changes of genes related to oxidative stress under conditions of oxygen depletion .…”

“…There is little information on whether ammonia and a decrease in content of dissolved oxygen in water induce oxidative stress in aquatic organisms. In the mussel Mytilus galloprovincialis exposed to acute hypoxic conditions, CAT activity decreased, but there was no significant change of SOD activity . The strategy and direction of antioxidative defense changes in hypoxia depend on many factors, including, for example, stress duration and intensity and the type of water ecosystem.…”

Sequencing, De Novo Assembly, and Annotation of the Transcriptome of the Endangered Freshwater Pearl Bivalve, Cristaria plicata, Provides Novel Insights into Functional Genes and Marker Discovery

“…The transcriptional stability of these genes is crucial under anthropogenic and pathogenic stresses and regulates cell homeostasis, as demonstrated in the mussel M . galloprovincialis [ 95 ]. SOD, CAT, and GPX were also identified in the C .…”