Sequence Analysis Of The S2 Glycoprotein Gene And E Gene Of Infectious Bronchitis Virus Strains In Sichuan, China

RT-PCR was employed to amplify 4 strain IBV, including one standard stains(M41,) and 3 strain isolates. And for the first time, the sequence analysis of three IBV isolates from Sichuan Province in China has been done. Two pairs of primer of the S2 and E gene was devised referring to the published sequence of IBV M41 (Massachusetts strain). A specific fragment of S2 gene about 1.50kb was produced by RT-PCR from four stains(M₄₁,SAIB_WS, SAIB₄ and SAIB_WJ), Another specific fragment of E gene about 0.40kb was produced by RT-PCR from four stains. The RT-PCR product of three isolates(SAIB_WS, SAIB₄and SAIB_WJ) was cloned and sequenced. The result shows that, the coding region of S2gene is about 1437bp in size, coding a 479-amino mat-peptide. the coding region of E gene is about 330bp in size, coding a 110-amino mat-peptide. Comparison of the gene sequences with the S2 gene of IBV M41 reference strain from Genebank(Accession: M21883), The nucleotide homology of SAIB_WS, SAIB₄and SAIB_WJ is respectively 85.5%, 84.4%and 84.4%, and the correspondingly amino-acid homology equal to 86.8%,88.7%and 81.6%. Comparison of the gene sequences with the E gene of IBV M41 reference strain from Genebank, The nucleotide homology of SAIBws, SAIB₄and SAIB_WJ is equal to 88.8%, and the correspondingly amino-acid homology equal to 87.3%.