5 GPR43 Genes in the Chicken Genome GBE which was claimed to be FFAR1 in chicken hepatocytes. Twenty-six chicken genes encoding paralogs of FFAR2 were accessible in old versions of Ensembl database but have been removed in the current version. In this article, we experimentally confirmed the existence of FFAR2 paralogs, examined their patterns of expression in different tissues, and studied their evolution by gene conversion and positive selection. Comparisons were made with pigs, where FFAR2 has been previously detected in adipose tissue and intestine. FFAs. In contrast, both FFAR2 and FFAR3 are selectively activated by short-chain FFAs from one to six carbon chain length. The pattern of expression of these receptors also differs, as previously shown in human and rodent species. FFAR1 expression has been mainly reported in pancreas, FFAR3 expression has been observed in many tissues with the highest level PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19812545 in white adipose tissue, and GPR84 is predominantly expressed in hematopoietic tissues and bone marrow. FFAR4 is widely expressed in various tissues and cell types including intestine, macrophages, adipose tissue, taste buds, brain, pancreas, lung, thymus, and 520-36-5 pituitary. Finally, FFAR2 is highly expressed in immune cells such as neutrophils, monocytes and peripheral blood mononuclear cells, but has been also detected in bone marrow, spleen, skeletal muscle, heart, adipose tissue, and intestine. Bovine FFAR2 was found in almost all tissues tested, with variations in adipose tissue according to the age of animals. Pig FFAR2 was also detected in adipose tissue and intestine. To our knowledge, only one study reported the expression of a chicken FFAR, claimed to be FFAR1 in chicken hepatocytes in vitro. Functional studies have highlighted different roles of FFAR family in human health. In particular, human loss-of-function variants of mouse FFAR2 and human FFAR4 have been shown to increase the risk to develop obesity. FFAR2 deficiency protects from high-fat diet-induced obesity and dyslipidemia, at least partly through increased energy expenditure. Mice overexpressing FFAR2 specifically in adipose tissue remain lean even when fed a high-fat diet. Furthermore, SCFAs have been described as key molecules produced by gut microbial fermentation of soluble fibers and the activation of FFAR2 by SCFAs has been involved in the regulation of energy balance. Taken together, it is suggested that FFAR2 may play a key role in lipid metabolism, glucose tolerance, immune regulation, and may be involved in the crosstalk between gut microbiota and whole-body homeostasis. Beside rodents, other animal organisms are now recognized for their potential interest in a better understanding of developmental biology, physiology, and human diseases. The chicken was the first avian species and domestic animal selected for complete genome sequencing and assembly. Chicken exhibit “natural” hyperglycemia but no signs of insulin resistance, making them a valuable model to understand the regulation of energy homeostasis. Like humans, de novo synthesis of lipids occurs mainly in the liver, whereas fat is deposited mainly at the visceral location. As stated above, only one study has reported the expression in vitro of a chicken FFAR to date, Materials and Methods Animals and Experimental Procedures Chicken Broilers were reared together in a closed building at the ex For accurate cell division, an exact copy of the genome must be equally transmitted from a mother cell to two d