title: Characterization of a novel gene up-regulated during anoxia exposure in the marine snail, Littorina littorea.
abstract: Gene expression was investigated during anoxia exposure in the marine snail, Littorina littorea. Differential screening of a cDNA library made from hepatopancreas of anoxic L. littorea yielded a 525 bp clone coding for the novel gene kvn. The deduced amino acid sequence of the KVN protein contained 99 amino acid residues with a predicted molecular weight of 12 kDa and showed an N-terminal secretory signal. Analysis of hepatopancreas samples over a time course of anoxia exposure showed a maximum increase in transcript levels of 5.8-fold after 48 h relative to normoxic animals, with a subsequent decrease in transcript levels during normoxic recovery. Nuclear run-off assays confirmed the observed transcriptional up-regulation of kvn during anoxia. Organ culture experiments were performed to determine a possible pathway of up-regulation of kvn, with data indicating a putative role for cGMP in signal transduction. Profiles of ribosome distribution in polysomes versus monosomes revealed a reduction in the polysome peak during anoxia and a shift in the position of kvn transcripts to association with the lower density polysome/higher density monosome region. The data suggest that the kvn transcript is both transcribed and translated during anoxia, indicating a possible significant role for the KVN protein in the survival of anoxia by L. littorea.
authors.affiliation: Institute of Biochemistry, Department of Biology, Carleton University, 1125 Colonel By Drive, Ontario, K1S 5B6, Ottawa, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Larade
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Storey
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004579:Electron Transport / Q000235:genetics; D005786:Gene Expression Regulation; D000860:Hypoxia / Q000503:physiopathology*; D008969:Molecular Sequence Data; D009924:Organ Culture Techniques; D011132:Polyribosomes / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012908:Snails / Q000235:genetics*; D014158:Transcription, Genetic; D015854:Up-Regulation
chemical_list: D018076:DNA, Complementary; D011506:Proteins; D012313:RNA