Oelkrug R, Polymeropoulos E T, Jastroch M
Department of Animal Physiology, Faculty of Biology, Philipps-Universität Marburg, Karl-von-Frisch Straße 8, 35043, Marburg, Germany,
J Comp Physiol B. 2015 Aug;185(6):587-606. doi: 10.1007/s00360-015-0907-7. Epub 2015 May 13.
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.
在现代真兽亚纲（有胎盘）哺乳动物中，棕色脂肪组织（BAT）进化成为一种专门的产热器官，负责适应性非颤抖性产热（NST）。对于非颤抖性产热，棕色脂肪组织线粒体的能量代谢通过解偶联蛋白1（UCP1）的激活而增加，UCP1将质子动力以热量的形式耗散掉。尽管在硬骨鱼和哺乳动物谱系分化之前就存在UCP1直系同源物，但UCP1对产热脂肪组织的重要性是在后来的进化阶段才出现的。最近关于有袋类动物（有袋目）和非洲兽总目真兽亚纲动物中棕色脂肪组织存在情况的研究，为哺乳动物适应性非颤抖性产热的进化提供了新的见解。特别是对“原始恒温”的刺猬猬（非洲兽总目）的研究，提出了一种将棕色脂肪组织与真兽亚纲动物恒温起源联系起来的进化假说。在这里，我们通过关注系统发育上不同物种的最新研究，在进化背景下综述棕色脂肪组织的生理功能和分布。
