Metabolic rate depression in animals: transcriptional and translational controls

Reviews the molecular controls that hold an animal in a depressed state, covering the suppression of transcription and translation, selective preservation of a small set of protective genes, and the reversible phosphorylation that makes the whole thing switchable.

Studied in

Animalia

Sample size

review

Depression is actively controlled rather than passive: the animal shuts most of its gene expression down while keeping a specific protective subset running, and the state is held by modifications that can be reversed quickly.

• Mechanistic work concentrated in a small number of model species — ground squirrels, wood frogs, snails and turtles — which are not a random sample of dormant animals.
• A review of the authors’ own research programme as much as of the field.

• Dormancy

  Hibernation, torpor, aestivation, diapause and cryptobiosis were named separately by different fields, but underneath they run much the same machinery. What actually differs is what starts them and how long they last.

• Dormancy

  A hibernating animal is not a stopped animal. Its metabolism falls further than the cold alone would explain, which means something is actively holding it down — and something is running the whole time to keep it alive.

• Torpor

  Hibernation is not continuous. Animals rewarm to near-normal temperature every week or two, and those arousals consume a large share of the energy the whole winter was meant to save. Why they do it is not settled.