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The evolution of uncoupling protein 1‐mediated nonshivering thermogenesis in vertebrates
Author(s) -
Jastroch Martin,
Klingenspor Martin
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.102
Subject(s) - thermogenin , biology , vertebrate , thermogenesis , brown adipose tissue , evolutionary biology , function (biology) , adipose tissue , gene , microbiology and biotechnology , genetics , biochemistry
Uncoupling protein 1 (UCP1)‐mediated nonshivering thermogenesis (NST) is a complex trait enabling modern eutherian mammals to maintain physiological functions despite fluctuations in ambient temperature. We aimed to shed light on the molecular evolution of NST and searched for UCPs in representative members of the major vertebrate groups. In contrast to previous expectations, we demonstrated the emergence of the UCP1 gene before the divergence of teleost fish and terrestrial vertebrates about 420 million yr ago. Although the physiological role of UCP1 in the fish liver may be other than heat production, fish UCP1 already displays an uncoupling function with similar biochemical characteristics as found in mammals. During evolution the prerogatives for UCP1‐mediated NST were set by changing the tissue‐specific expression of UCP1. In marsupials, which separated from eutherians about 150 million yr ago, we found cold‐induced gene expression in adipose tissue providing the molecular basis for NST. The thermogenic function of UCP1, however, must have evolved at least 100 million yr ago as functional brown adipose tissue could be identified in an Afrotherian species. The reconstruction of the evolutionary events resulting in UCP1‐mediated NST opens an exiting field to gain further insights into the regulation, integration and the molecular mechanisms underlying UCP1.