title: Brown adipose tissue: physiological function and evolutionary significance.
abstract: In modern eutherian (placental) mammals, brown adipose tissue (BAT) evolved as a specialized thermogenic organ that is responsible for adaptive non-shivering thermogenesis (NST). For NST, energy metabolism of BAT mitochondria is increased by activation of uncoupling protein 1 (UCP1), which dissipates the proton motive force as heat. Despite the presence of UCP1 orthologues prior to the divergence of teleost fish and mammalian lineages, UCP1's significance for thermogenic adipose tissue emerged at later evolutionary stages. Recent studies on the presence of BAT in metatherians (marsupials) and eutherians of the afrotherian clade provide novel insights into the evolution of adaptive NST in mammals. In particular studies on the 'protoendothermic' lesser hedgehog tenrec (Afrotheria) suggest an evolutionary scenario linking BAT to the onset of eutherian endothermy. Here, we review the physiological function and distribution of BAT in an evolutionary context by focusing on the latest research on phylogenetically distinct species.
authors.affiliation: Department of Animal Physiology, Faculty of Biology, Philipps-Universität Marburg, Karl-von-Frisch Straße 8, 35043, Marburg, Germany, rebecca.oelkrug@uni-bonn.de.
authors.forename: R
authors.initials: R
authors.lastname: Oelkrug
authors.forename: E T
authors.initials: ET
authors.lastname: Polymeropoulos
authors.forename: M
authors.initials: M
authors.lastname: Jastroch
mesh_terms: D002001:Adipose Tissue, Brown / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D000975:Antioxidants / Q000378:metabolism; D005075:Biological Evolution; D001835:Body Weight; D005260:Female; D006801:Humans; D007473:Ion Channels / Q000378:metabolism; D008322:Mammals / Q000502:physiology; D008394:Marsupialia / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000378:metabolism; D010802:Phylogeny; D012098:Reproduction / Q000502:physiology; D012377:Rodentia / Q000502:physiology; D022722:Thermogenesis / Q000502:physiology*; D000071256:Uncoupling Protein 1
chemical_list: D000975:Antioxidants; D007473:Ion Channels; D024101:Mitochondrial Proteins; C000604371:UCP1 protein, human; D000071256:Uncoupling Protein 1