Cloning and Sequence Analysis of N Gene of Transmissible Gastroenteritis Virus HYM-09 Isolated from Dog in China

Man, Chaolai; Yu, Xiaolong

Transmissible gastroenteritis virus (TGEV) is the etiological agent of TGE, and dogs are potential carriers of TGEV. In this study, genomic RNA were extracted from TGEV designated HYM-09 isolated from dog naturally infected with TGEV. The nucleocapsid (N) gene of HYM-09 was amplified by RT-PCR and cloned into pMD18-T vector. The N gene cDNA was sequenced and encompassed an open reading frame of 1,149 nucleotides, encoding a 382-amino acids protein. Sequence analyses of the N genes were performed, including homologous comparison, phylogenetic tree analysis and residue substitution analysis. The results showed that there existed some unique mutations in the HYM-09 isolate N gene, but HYM-09 N gene shared over 96 % homologous identities compared with 12 TGEV reference strains derived from other regions or countries respectively. The phylogenetic tree analysis revealed that the HYM-09 branched into the most strains group. This study shows that the nucleotide sequence analysis can form a base or further study on the mutation trend of non-porcine TGEV.