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Journal of Comparative Physiology B

, Volume 172, Issue 5, pp 355–361 | Cite as

Reversible depression of transcription during hibernation

  •  F. van Breukelen
  •  S. Martin
Original paper

Abstract.

Mammalian hibernators downregulate processes of energy production and consumption while maintaining cellular homeostasis. Energetic costs of transcription must be balanced with demands for gene products. Data from nuclear run-on assays indicate transcriptional initiation is reduced two fold in torpid golden-mantled ground squirrels (Spermophilus lateralis) as compared to euthermic animals between bouts of torpor. In addition, elongation rates across the temperature range experienced by hibernators indicate a virtual arrest of transcription at the low body temperatures of torpor. Finally, there is no seasonal compensation or species-specific adaptation for increased elongational capacity in the cold. Thus, it appears that hibernators are not specifically adapted to continue transcription during torpor. Taken together, these data indicate that transcription arrests during torpor because of a moderate depression of initiation and a more severe inhibition of elongation, largely due to temperature effects. Restoration of euthermic body temperatures during the interbout arousals reverses this transcriptional depression and permits gene expression.

Nuclear run-on assay RNA synthesis Gene expression Torpor 

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Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  •  F. van Breukelen
    • 1
  •  S. Martin
    • 1
  1. 1.Department of Cellular and Structural Biology, University of Colorado School of Medicine, 4200 East Ninth Avenue, Denver, CO 80262-B111

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