Quasispecies investigation on swine hepatitis E viruses

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.