鸡传染性支气管炎病毒LX4株 mRNA5和mRNA6 cDNA的分子特征

The Molecular Characteristics of mRNA_5 and mRNA_6 cDNA of Infectious bronchitis virus LX4 Isolated in China

According to the published IBV gene sequence, a pair of specific primers were designed and synthesized. A fragment of 1.7kb including mRNAs and mRNA_6 cDNA of infectious bronchitis virus LX4 was amplified, cloned and sequenced. Then the nucleotide and the deduced amino acid sequence of this fragment were analyzed. The results showed that N gene of IBV LX4 sharedthe highest identity with SD/97/02 and HB that were both isolated in China. However, the identity is different in three conservative basic regions of N protein. The deduced amino acid sequence of LX4 shared the highest identity with M41,Beau, H52 and HB in position 66-88, with SD/97/02 strain in position 181-234 and with H120 and ZJ971 in position 334-373 respectively. Meanwhile, we found that LX4 and H120 showed completely identical in position 350-409 both in corresponding nucleotide and deduced amino acid. All these data above showed that mRNA_5 and mRNA_6 cDNA of IBV LX4 shared more characteristics with other isolates in China than the aboard. In addition, the relationship between LX4 and the two vaccine IBV strains, namely H52 and HI20, was also found in nucleocapsid gene and its functional regions.