title: Sequence and expression analysis of rainbow trout CXCR2, CXCR3a and CXCR3b aids interpretation of lineage-specific conversion, loss and expansion of these receptors during vertebrate evolution.
abstract: The chemokine receptors CXCR1-3 bind to 11 chemokines (CXCL1-11) that are clustered on the same chromosome in mammals but are largely missing in ray-finned fish. A second CXCR1/2, and a CXCR3a and CXCR3b gene have been cloned in rainbow trout. Analysis of CXCR1-R3 genes in lobe-finned fish, ray-finned fish and tetrapod genomes revealed that the teleostomian ancestor likely possessed loci containing both CXCR1 and CXCR2, and CXCR3a and CXCR3b. Based on this synteny analysis the first trout CXCR1/2 gene was renamed CXCR1, and the new gene CXCR2. The CXCR1/R2 locus was shown to have further expanded in ray-finned fish. In relation to CXCR3, mammals appear to have lost CXCR3b and birds both CXCR3a and CXCR3b during evolution. Trout CXCR1-R3 have distinct tissue expression patterns and are differentially modulated by PAMPs, proinflammatory cytokines and infections. They are highly expressed in macrophages and neutrophils, with CXCR1 and CXCR2 also expressed in B-cells.
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK; School of Animal Science, Yangtze University, Jingzhou, Hubei Province 434020, China.
authors.forename: Qiaoqing
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK.
authors.forename: Ronggai
authors.initials: R
authors.lastname: Li
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK.
authors.forename: Milena M
authors.initials: MM
authors.lastname: Monte
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK; College of Fishery and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Yousheng
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province 430072, China.
authors.forename: Pin
authors.initials: P
authors.lastname: Nie
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Holland
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK. Electronic address: c.secombes@abdn.ac.uk.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Secombes
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, UK. Electronic address: t.h.wang@abdn.ac.uk.
authors.forename: Tiehui
authors.initials: T
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019143:Evolution, Molecular; D005393:Fish Diseases / Q000276:immunology / Q000382:microbiology / Q000469:parasitology; D029941:Fish Proteins / Q000235:genetics* / Q000276:immunology; D060226:Head Kidney / Q000276:immunology; D006801:Humans; D007239:Infections / Q000276:immunology / Q000382:microbiology / Q000469:parasitology / Q000662:veterinary; D008264:Macrophages / Q000276:immunology; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000276:immunology*; D009928:Organ Specificity; D010802:Phylogeny; D054387:Receptors, CXCR / Q000235:genetics* / Q000276:immunology; D016415:Sequence Alignment
chemical_list: D029941:Fish Proteins; D054387:Receptors, CXCR
keywords: CXCR2; CXCR3a; CXCR3b; Evolution; Expression; Rainbow trout