Submitted on August 10, 2007
Accepted on October 20, 2007
Marsupial uncoupling protein 1 sheds light on the evolution of mammalian nonshivering thermogenesis
Martin Jastroch1*, Kerry William Withers2, Stefan Taudien3, Peter B. Frappell4, Michael Helwig1, Tobias Fromme1, Verena Hirschberg1, Gerhard Heldmaier5, Bronwyn M McAllan6, Bruce T Firth7, Thorsten Burmester8, Matthias Platzer3, and Martin Klingenspor5
1 Animal Physiology, Philipps-Universitat, Marburg, Hessen, Germany
2 Department of Biological and Physical Sciences, University of Southern Queensland, Toowoomba, Queensland, Australia
3 Genome Analysis, Leibniz-Institute for Age Research - Fritz Lipmann Institute, Jena, Germany
4 Zoology, LaTrobe University, Melbourne, Victoria, Australia
5 Department of Biology, Phillipps-University, D-35032 Marburg, United States
6 School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
7 School of Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
8 University of Hamburg, Institute of Zoology, Hamburg, Germany
* To whom correspondence should be addressed. E-mail: jastroch{at}staff.uni-marburg.de.
Brown adipose tissue expressing uncoupling protein 1 (UCP1) is responsible for adaptive nonshivering thermogenesis giving eutherian mammals crucial advantage to survive the cold. The emergence of this thermogenic organ during mammalian evolution remained unknown as the identification of UCP1 in marsupials failed so far. Here, we unequivocally identify the marsupial UCP1 orthologue in a genomic library of Monodelphis domestica. In South American and Australian marsupials, UCP1 is exclusively expressed in distinct adipose tissue sites and appears to be recruited by cold exposure in the smallest species under investigation (Sminthopsis crassicaudata). Our data suggest that an archetypal brown adipose tissue was present at least 150 million years ago allowing early mammals to produce endogenous heat in the cold, without dependence on shivering and locomotor activity.
