title: The first non-mammalian CXCR3 in a teleost fish: gene and expression in blood cells and central nervous system in the grass carp (Ctenopharyngodon idella).
abstract: A novel fish chemokine receptor gene, chemokine (C-X-C motif) receptor 3 (CXCR3)-like was isolated from the grass carp Ctenopharyngodon idella, with its full-length genomic sequence. The cDNA of grass carp CXCR3-like (gcCXCR3-like) consists of 1261 bp with a 49 bp 5'-UTR and a 189bp 3'-UTR. An open reading frame of 1023 bp encodes a 341-amino acid peptide, with seven transmembrane helices. The deduced amino acid sequence showed the same sequence identities (37.8%) with its counterparts in goat and human. The gcCXCR3-like gene consists of two exons, with one intervening intron, spaced over approximately 2 kb of genomic sequence. Phylogenetic analyses clearly demonstrated that the gcCXCR3-like resembles the CXCR3s of other vertebrates. Real-time PCR analysis showed that gcCXCR3-like was expressed in all tested organs except heart and the expression level of gcCXCR3-like was highest in brain. Flow cytometric analyses showed the positive rate of labelled leukocytes from the healthy grass carp was 17.3%, and the labelled leukocytes were divided into three types by cell sorting. Immunohistochemical localization revealed that gcCXCR3-like expressed in whole brain regions including cerebel, diencephalon, medulla oblongata, optic lobe, and rhinencephalon, and that the labelled leukocytes are actually populations of monocyte and/or phagocyte, lymphocyte and the granulocyte. It is considered that fish CXCR expression and their function may need to be investigated in both nervous and immune systems.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Laboratory of Fish Diseases, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei Province, China.
authors.forename: M X
authors.initials: MX
authors.lastname: Chang
authors.forename: B J
authors.initials: BJ
authors.lastname: Sun
authors.forename: P
authors.initials: P
authors.lastname: Nie
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001773:Blood Cells / Q000378:metabolism*; D002347:Carps / Q000235:genetics* / Q000276:immunology; D002490:Central Nervous System / Q000276:immunology* / Q000378:metabolism*; D018076:DNA, Complementary; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine / Q000096:biosynthesis / Q000235:genetics*
chemical_list: C515187:CXCR3 protein, human; D018076:DNA, Complementary; D009419:Nerve Tissue Proteins; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine