title: Transcriptional analysis of disk abalone (Haliotis discus discus) antioxidant enzymes against marine bacteria and virus challenge.
abstract: Diverse antioxidant enzymes are essential for marine organisms to overcome oxidative stress as well as for the fine-tuning of immune reactions through activating different signal transduction pathways. This study describes the transcriptional analysis of antioxidant enzymes of disk abalone by challenging with bacteria (Vibrio alginolyticus, Vibrio parahemolyticus, and Listeria monocytogenes) and viral hemorrhagic septicemia virus (VHSV). Upon bacteria and VHSV challenge, Manganese superoxide dismutase (MnSOD), Copper, Zinc superoxide dismutase (CuZnSOD), catalase, thioredoxin peroxidase (TPx), Selenium-dependent glutathione peroxidase (SeGPx), and thioredoxin-2 (TRx-2) expression levels were altered in gills, and hemocytes at different magnitudes. In gills, only MnSOD, catalase, and SeGPx genes were completely upregulated by post-challenge of bacterial and VHSV. Among them, SeGPx demonstrated strong upregulation by 16-fold (bacteria) and 2-fold (VHSV) in gills, and 5-fold (bacteria) and 3.0-fold (VHSV) in hemocytes. None of the genes examined were downregulated (in gills and hemocytes) by bacteria challenge even though CuZnSOD and TPx showed downregulation (completely) in hemocytes by VHSV. In general, abalone hemocytes had lower potential to induce antioxidant enzyme transcripts upon bacteria and VHSV challenge than gills. Based upon these results, we suggest that abalones induce oxidative stress in tissues during the bacteria and VHSV challenge, and the identified response of antioxidant enzymes could be supported for maintaining a low-level of reactive oxygen species (ROS) that may serve as a signal for activating immune reactions against pathogenic conditions.
authors.affiliation: College of Veterinary Medicine, Chungnam National University, Yuseong-gu, Daejeon 305-764, Republic of Korea.
authors.forename: Mahanama
authors.initials: M
authors.lastname: De Zoysa
authors.forename: Ilson
authors.initials: I
authors.lastname: Whang
authors.forename: Chamilani
authors.initials: C
authors.lastname: Nikapitiya
authors.forename: Chulhong
authors.initials: C
authors.lastname: Oh
authors.forename: Cheol Young
authors.initials: CY
authors.lastname: Choi
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D029941:Fish Proteins / Q000378:metabolism*; D049851:Gastropoda / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005880:Gills / Q000378:metabolism; D006434:Hemocytes / Q000378:metabolism; D008089:Listeria monocytogenes / Q000502:physiology; D029141:Novirhabdovirus / Q000502:physiology; D018384:Oxidative Stress; D020133:Reverse Transcriptase Polymerase Chain Reaction; D044149:Vibrio alginolyticus / Q000502:physiology; D014736:Vibrio parahaemolyticus / Q000502:physiology
chemical_list: D000975:Antioxidants; D029941:Fish Proteins