ABSTRACT
The objective of current study was to investigate the quasispecies of hepatitis E virus in swine. The partial ORF2 region of HEV envelope gene from four swine HEV strains was amplified by RT-nested polymerase chain reaction (RT-nPCR). After cloning and transformation of PCR products, 20 positive clones of each HEV isolate were subject to sequencing and DNA analysis. The homology among the different clones of each isolates was 96.8%-99.7%, 98.8%-99.7%, 98.8%-99.7% and 100%, respectively, while there was 96.8%-100% sequence identity at the nucleotide level compared with HEV strains isolated in Shanghai (SAAS-JDY5). This study confirmed that there existed quasispecies of HEV in swine.
Subject(s)
Animals , Amino Acid Sequence , Base Sequence , China , Disease Reservoirs , Virology , Hepatitis E , Virology , Hepatitis E virus , Chemistry , Classification , Genetics , Mutation , Open Reading Frames , Phylogeny , Sequence Alignment , Sequence Analysis, DNA , Swine , VirologyABSTRACT
By using huge primer PCR Cys86 (TGC) of PoIFN-alpha was mutated to Tyr(TAC), and the first code TGT was simultaneously changed to TGC, which is a bias code of E. coli. The expression plasmid pGEX-IFN was constructed successfully. Recombinant porcine IFN alpha, which is expressed as inclusion bodies, was about 20% of the total proteins. The inclusion body was dissolved in 8 mol/L urea and subsequently renatured by dilution in refolding buffer. In order to obtain pure protein, the renatured IFN alpha was purified by FPLC, and the cytokine activity (5200 IU/mg) was verified by inhibiting the cytopathic effect.