African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5056

Full Length Research Paper

New mutations existing in the nucleocapsid (N) gene of non-porcine TGEV strains isolated in China

Chaolai Man1 and Xiaolong Yu2*
  1Key Laboratory of Molecular Cytogenetics and Genetic Breeding of Heilongjiang Province, College of Life Science and Technology, Harbin Normal University, Harbin, 150025, P. R. China. 2Institute of Animal Science, Heilongjiang Academy of Agricultural Sciences, Harbin 150086, P. R. China.
Email: [email protected]

  •  Accepted: 22 August 2011
  •  Published: 16 December 2011

Abstract

 

Transmissible gastroenteritis virus (TGEV) is the etiological agent of TGE, and non-porcine hosts are potential carriers of TGEVs. In this study, genomic RNA were extracted from TGEVs designated HYM-09, HYM-09-1 and HYM-09-2 isolated respectively from non-porcine hosts (dogs, cats and foxes) naturally infected with TGEVs. The nucleocapsid (N)genes of the three non-porcine TGEV strains were amplified by RT-PCR and cloned into pMD18-T vector respectively. Each N cDNA was sequenced and encompassed an open reading frame of 1149 nucleotides, encoding a 382-amino acids protein. Sequence analyses of the N genes were performed, including homologous comparison, phylogenetic tree analysis and homology modeling. The results showed that there existed some new point mutations in the three non-porcine TGEV isolates N genes. The phylogenetic tree analysis revealed that these non-porcine TGEVs N genes had closer genetic relationships and evolution distance to the N genes of Chinese TGEV strains. The three-dimensional structure of the N protein (32-154AA (amino acid)) of HYM-09-2 generated by homology modeling was different from that of other TGEV strains (including HYM-09 and HYM-09-1).These data serve as a foundation for further insight into the virulence or mutation rates of the non-porcine TGEVs.

 

Key words: N gene, cloning, TGEV, non-porcine, phylogenetic analysis, homology modeling.