title: De novo assembly of the ringed seal (Pusa hispida) blubber transcriptome: A tool that enables identification of molecular health indicators associated with PCB exposure.
abstract: The ringed seal, Pusa hispida, is a keystone species in the Arctic marine ecosystem, and is proving a useful marine mammal for linking polychlorinated biphenyl (PCB) exposure to toxic injury. We report here the first de novo assembled transcriptome for the ringed seal (342,863 transcripts, of which 53% were annotated), which we then applied to a population of ringed seals exposed to a local PCB source in Arctic Labrador, Canada. We found an indication of energy metabolism imbalance in local ringed seals (n=4), and identified five significant gene transcript targets: plasminogen receptor (Plg-R(KT)), solute carrier family 25 member 43 receptor (Slc25a43), ankyrin repeat domain-containing protein 26-like receptor (Ankrd26), HIS30 (not yet annotated) and HIS16 (not yet annotated) that may represent indicators of PCB exposure and effects in marine mammals. The abundance profiles of these five gene targets were validated in blubber samples collected from 43 ringed seals using a qPCR assay. The mRNA transcript levels for all five gene targets, (Plg-R(KT), r2=0.43), (Slc25a43, r2=0.51), (Ankrd26, r2=0.43), (HIS30, r2=0.39) and (HIS16, r2=0.31) correlated with increasing levels of blubber PCBs. Results from the present study contribute to our understanding of PCB associated effects in marine mammals, and provide new tools for future molecular and toxicology work in pinnipeds.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada; Memorial University, St. John's, Newfoundland A1B 3X9, Canada.
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Brown
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada; Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, BC V5Z 4S6, Canada.
authors.forename: S Austin
authors.initials: SA
authors.lastname: Hammond
authors.affiliation: Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, BC V5Z 4S6, Canada.
authors.forename: Bahar
authors.initials: B
authors.lastname: Behsaz
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.
authors.forename: Nik
authors.initials: N
authors.lastname: Veldhoen
authors.affiliation: Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, BC V5Z 4S6, Canada.
authors.forename: Inanç
authors.initials: I
authors.lastname: Birol
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada. Electronic address: chelbing@uvic.ca.
authors.forename: Caren C
authors.initials: CC
authors.lastname: Helbing
mesh_terms: D000825:Animal Structures / Q000378:metabolism*; D000818:Animals; D004781:Environmental Exposure / Q000032:analysis*; D020869:Gene Expression Profiling; D063990:Gene Ontology; D006305:Health Status Indicators; D058977:Molecular Sequence Annotation; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D046048:Seals, Earless / Q000235:genetics*; D017423:Sequence Analysis, RNA; D059467:Transcriptome / Q000235:genetics*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls
keywords: Pinniped; Polychlorinated biphenyls; RNA-seq; Ringed seal; Transcriptome; de novo assembly