Cloning and Sequence Analysis of S1 Gene of Avian infectious bronchitis virus KIBVXJ Strain

A pair of primers were designed and synthesized according to the published S1 gene of avian infectious bronchitis virus(IBV).The full-length S1 gene was amplified by RT-PCR.The complete nucleotide sequence of S1 gene was about 1 700 bp.The sequence analysis indicated that the biggest ORF of S1 gene was between 12 to 1 685 bp and coded 557 amino acids.There were some replacement,insertion and deletion in S1 amino acid sequence at the position of 19-292 amino acids of KIBVXJ strain.The sequence of S1 cleavage site is HRRRR,which was consistent to the characteristic of the epidemic IBV strains in China.By comparing the S1 gene of KIBVXJ strain with the attenuated virus vaccine strains,the nucleotide homology was 73.8%-74.2% and the amino acid homology was 74.9%-76.0%.The genetic evolution analysis showed that KIBVXJ strain had far relationship with the vaccine strains and had the closest relationship with the strains which isolated in recent years.