Cloning And Sequence Analysis Of The S2,S4Gene Of Avian Reovirus

According to the S2and S4gene sequence of Avian reovirus strain176(ARV176) published in GenBank,two pairs of primers were synthesized.The total RNA of ARV isolate T-98and C-98isolated in Tianjin and inner Mongolia were extracted.The S2and S4gene of virus was amplificated by RT-PCR and then cloned into pESAY-T1plasmid and then sequenced. The result showed that the S2gene was1,324bp,and contained one ORF(16-1266bp)which codes416amino acids with1251bp and two non-coding regions.and the S4gene was1192bp, and contained one ORF(24-1127bp)which codes367amino acids with1104bp and two non-coding regions. The nucleotide sequences of S2and S4genes reported in this study have been submitted to the GenBank, the accession numbers of S2and S4genes include:C-98S2(JN641886);C-98S4(JN641885);T-98S2(JN641887);T-98S4(JN641884).The sequences were compared with reference strains gene sequences by computer software. The homology of S2gene was about99.2%to99.8%compared with reference strains ARV176、ARV918、ARV919、ARV1733、ARV GX2010、ARV S1133、DRV YJL and the deduced amino acids sequences ranged from98.1%to99.8%; Compared with reference strains MRV3、MRV3-jin-1、MRV3-T3D the homologies of the nucleotide sequence of S2gene ranged from2.4%to5.5%and the deduced amino acids sequences ranged from29.1%to29.3%. The homology of S4gene was about99.0%to99.8%compared with reference strains ARV176、ARV601SI、ARV919、ARV1733、ARV GX2010、ARV S1133、DRV YJLand the deduced amino acids sequences ranged from98.9%to100.0%; Compared with reference strains MRV3、MRV3-jin-1、MRV3-T3D the low homologies of the nucleotide sequence of S4gene was2.4%and the deduced amino acids sequences ranged from3.6%to9.0%.Results of phylogenetic tress indicated that S2genes have diverged into three distinct lineages and S4genes have diverged into four distinct lineages, and that there was no correlation between lineages and viral serotypes, pathotypes and origins, but ARV C-98、ARV T-98、ARV176、ARV S1133、 ARV1733、ARV919、ARV GX2010、DRV YJL contained the S2and S4genes which were consistently located in the same respective lineages, the remaining virus strains demonstrated reassortment of either one of S2or S4genes.