Genotype Determination and Sequencing of S1 Glycoprotein Genes of Infectious Bronchitis Viruses in Taiwan

• Main Authors: Chang, Pan-Chung, 張泮崇
• Other Authors: Wang, Ching-Ho
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/57079548910296951355

碩士 === 國立臺灣大學 === 獸醫學系 === 84 === In order to differentiate the infectious bronchitis virus (IBV) isolates in Taiwan, polymerase chain reaction and restric- tion fragment length polymorphism (PCR-RFLP) were used to type 12 Taiwan isolates of IBV. Two sets of primers were used in this study to amplify the whole length of S1 glycoprotein gene. PCR products were digested with three restriction enzymes, i.e., HaeIII, XcmI and BstYI. Four RFLP patterns were obtained and they were different from those of all foreign IBV strains; the foreign strains are divided into 4 different genetic groups, i. e., Dutch, American, European and Massachusetts. Two IBV Taiwan isolates were selected for S1 gene cloning and sequencing. The nucleotide sequences of these two isolates have 94% similiarity, and those of the deduced amino acid sequence are 90%. The two isolates are close to the Massachusetts group by phylogenetic analysis. The amino acid sequences of the proteolytic cleavage site between the S1 and S2 glycoproteins of the two isolates are both RRFRR, and it is the same with the Massachusetts group. Four consensus-like sequence, CTT(A/T)(A/T) G, are noted in both of the two isolates but no recombination are found.