title: Elevated expression of protein biosynthesis genes in liver and muscle of hibernating black bears (Ursus americanus).
abstract: We conducted a large-scale gene expression screen using the 3,200 cDNA probe microarray developed specifically for Ursus americanus to detect expression differences in liver and skeletal muscle that occur during winter hibernation compared with animals sampled during summer. The expression of 12 genes, including RNA binding protein motif 3 (Rbm3), that are mostly involved in protein biosynthesis, was induced during hibernation in both liver and muscle. The Gene Ontology and Gene Set Enrichment analysis consistently showed a highly significant enrichment of the protein biosynthesis category by overexpressed genes in both liver and skeletal muscle during hibernation. Coordinated induction in transcriptional level of genes involved in protein biosynthesis is a distinctive feature of the transcriptome in hibernating black bears. This finding implies induction of translation and suggests an adaptive mechanism that contributes to a unique ability to reduce muscle atrophy over prolonged periods of immobility during hibernation. Comparing expression profiles in bears to small mammalian hibernators shows a general trend during hibernation of transcriptional changes that include induction of genes involved in lipid metabolism and carbohydrate synthesis as well as depression of genes involved in the urea cycle and detoxification function in liver.
authors.affiliation: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska 99775, USA. fnvf@uaf.edu
authors.forename: Vadim B
authors.initials: VB
authors.lastname: Fedorov
authors.forename: Anna V
authors.initials: AV
authors.lastname: Goropashnaya
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Tøien
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Stewart
authors.forename: Andrew Y
authors.initials: AY
authors.lastname: Gracey
authors.forename: Celia
authors.initials: C
authors.lastname: Chang
authors.forename: Shizhen
authors.initials: S
authors.lastname: Qin
authors.forename: Geo
authors.initials: G
authors.lastname: Pertea
authors.forename: John
authors.initials: J
authors.lastname: Quackenbush
authors.forename: Louise C
authors.initials: LC
authors.lastname: Showe
authors.forename: Michael K
authors.initials: MK
authors.lastname: Showe
authors.forename: Bert B
authors.initials: BB
authors.lastname: Boyer
authors.forename: Brian M
authors.initials: BM
authors.lastname: Barnes
mesh_terms: D000818:Animals; D001481:Basal Metabolism; D001831:Body Temperature; D020869:Gene Expression Profiling; D015723:Gene Library; D023281:Genomics / Q000379:methods; D006605:Hibernation / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D014176:Protein Biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D001503:Ursidae / Q000235:genetics* / Q000378:metabolism / Q000502:physiology