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PPAR Research
Volume 2013 (2013), Article ID 186312, 7 pages
http://dx.doi.org/10.1155/2013/186312
Review Article

Structural Features and Transcriptional Activity of Chicken PPARs ( , , and )

1Department of Cell and Tissue Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan
2Department of Microbiology and Immunology, School of Medicine, Keio University, Tokyo 160-8582, Japan
3Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara 630-0192, Japan

Received 5 October 2012; Revised 11 December 2012; Accepted 12 December 2012

Academic Editor: Juan J. Loor

Copyright © 2013 Ichiro Takada and Mime Kobayashi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

While an understanding of lipid metabolism in chickens is critical for a further improvement of food production, there are few studies concerning differences in lipid metabolism mechanisms between chickens and other species at a molecular level. Chickens have three PPAR gene subtypes (α, β, and γ) that function differently from those present in humans and mice. The chicken PPAR-gamma (cPPARγ) gene is shorter than that in humans and lacks a γ2 isoform. Moreover, in serum-free media, cPPARγ shows high transcriptional activity without exogenous ligands. Luciferase reporter assays were used to examine the effect of sera on cPPAR transcriptional activities and showed that adult bovine serum and chicken serum highly activate cPPARα and β functions. Moreover, we found that bezafibrate induces the transactivation function of cPPARβ, but not human PPARδ (human PPARβ ortholog). This ligand selectivity relies on one amino acid residue (chicken: Val419, human: Met444). These results show the possibilities for unique functions of cPPARs on chicken-specific lipid glucose metabolism. As such, a better understanding of the molecular mechanisms of lipid metabolism in chickens could result in higher productivity for the poultry industry.