title: Molecular cloning and phylogenetic analysis of ORF7 region of chinese isolate TH-98 from transmissible gastroenteritis virus.
abstract: Genomic RNA was extracted from a Chinese isolate of porcine transmissible gastroenteritis virus (TGEV) designated TH-98. Employing RT-PCR technique to amplify ORF7 sequence of TGEV, which located at the 3' end of TGEV genome and is poorly understood functionally so far. A recombinant named pPROEX HTc-hp was constructed via inserting ORF7 gene into prokaryotic expression vector pPROEX HTc. The recombinant was sequenced and compared the DNA and its deduced amino acid (aa) sequences with that of some reference strains after restriction endonuclease and PCR analysis. The ORF7 gene named hp gene (Genbank accession number: AY337931) consists of 237 bp in length encoding a hydrophobic protein (HP) of 78 aa with a molecular weight of 9.1 kDa. The sequences of hp gene and Hp protein share 89%-97% and 87%-96% homologous identities compared with 11 TGEV reference strains derived from other regions or countries respectively, which revealed that there are significant variation within-strains, even though the ORF7 region is relatively conservative. In addition, a phylogenetic tree based on these ORF7 DNA sequences was generated, and the tree topology suggests that possible recombination events happened in the evolutionary history of TGEV.
authors.affiliation: Department of Preventive Veterinary, College of Veterinary Medicine, Northeast Agriculture University, 59 Mucai Street, 150030, Harbin, China.
authors.forename: Jie-Chao
authors.initials: JC
authors.lastname: Yin
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Ren
authors.forename: Yi-Jing
authors.initials: YJ
authors.lastname: Li
mesh_terms: D000818:Animals; D001483:Base Sequence; D002681:China; D005761:Gastroenteritis, Transmissible, of Swine / Q000821:virology; D057927:Hydrophobic and Hydrophilic Interactions; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000235:genetics*; D011995:Recombination, Genetic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013552:Swine; D005760:Transmissible gastroenteritis virus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins