Quantitative and qualitative changes in gene expression during hibernationin golden-mantled ground squirrels

Differential gene expression is likely to play a significant role in determ ining the phenotype of hibernation. Crucial gene products may facilitate en trance, maintenance and survival of the hibernating state. This study repor ts the results obtained using two-dimensional gels to assess qualitative di fferences in the liver proteins between active and hibernating animals. Qua ntitative changes in the translational and transcriptional machinery are as sessed by comparing polysome profiles and transcriptional run-off assays, r espectively. In liver, about 10% of the gene products we are able to resolv e by two-dimensional electrophoresis diminish during hibernation and about 3% are upregulated. During torpor, mRNAs are no longer associated with poly somes and the initiation of transcription is significantly reduced. Both tr anslation and transcription are fully reactivated during interbout arousal.