title: Cloning, sequence analysis and expression profiles of Toll-like receptor 7 from Chinese giant salamander Andrias davidianus.
abstract: The Chinese giant salamander, Andrias davidianus, is the largest extant amphibian species in the world, which is of significance due to its specific position in the evolutionary history of vertebrates. Currently, limited information about the innate immune system of this animal is known. In this study, the toll-like receptor 7 (TLR7), designated CgsTLR7, was cloned from Chinese giant salamander, A. davidianus. The full-length cDNA of CgsTLR7 is 3747 bp, with an open reading frame of 3150 bp, encoding 1049 amino acids. The TLR family motifs, including the leucine-rich repeat (LRR) and Toll/interleukin (IL)-1 receptor (TIR) domain are conserved in CgsTLR7, which includes 19 LRRs and a TIR domain. The predicted amino acid sequence of CgsTLR7 has 71%, 65%, 63% and 55% identity with turtle, chicken, human and fugu TLR7 homologues, respectively. Phylogenetic analysis showed that CgsTLR7 is closest to that of frog TLR7 among the examined species. Quantitative real-time PCR analysis revealed broad expression of CgsTLR7 in tissues from apparently healthy Chinese giant salamanders with the highest expression in the liver and the lowest expression in the intestine. The mRNA expression was up-regulated and reached a peak level in the kidney, liver and spleen at 12 h, 24 h and 48 h after infecting the animals with the giant salamander iridovirus (GSIV), respectively. These results suggest that CgsTLR7 has a conserved gene structure and might play an important role in immune regulation against viral infections in the Chinese giant salamander.
authors.affiliation: College of Fisheries and Biosciences, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Huang
authors.affiliation: Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, Hubei 430223, China.
authors.forename: Yuding
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, Hubei 430223, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, Hubei 430223, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, Hubei 430223, China.
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Liu
authors.affiliation: Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, Hubei 430223, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Meng
authors.affiliation: College of Fisheries and Biosciences, Shanghai Ocean University, Shanghai 201306, China; Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, Hubei 430223, China. Electronic address: zlb@yfi.ac.cn.
authors.forename: Lingbing
authors.initials: L
authors.lastname: Zeng
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000235:genetics* / Q000276:immunology; D000818:Animals; D003001:Cloning, Molecular; D017994:Iridovirus / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013154:Spleen / Q000378:metabolism; D051199:Toll-Like Receptor 7 / Q000235:genetics* / Q000276:immunology; D059467:Transcriptome; D014562:Caudata / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism / Q000821:virology
chemical_list: D029845:Amphibian Proteins; D051199:Toll-Like Receptor 7
keywords: Chinese giant salamander; Expression profile; Iridovirus; TLR7