Cloning and Sequence Analysis of gB Gene of Chicken Infectious Laryngotracheitis Virus Henan Isolate

One pair of primers was designed and synthesized based on the nucleotide sequence(M64927)of chicken infectious laryngotracheitis virus(ILTV) gB gene pulished in the GenBank.gB gene of ILTV Henan isolate(ILTV-CG) was amplified by PCR.The purified PCR product was inserted into pGEM-T Easy vector,and then transformed competent cell JM109.By idenfication of blue-white colony screening,plasmid PCR and enzyme digestion,positive clones were sequenced.The sequencing results indicated that gB gene nucleotide sequence of ILTV-CG strain was 2 629 bp in length,which included one openreading frame(2 622 bp,encoding 873 amino acid residues,with eight potential N-glycosalation sites and twelve cysteines in deduced amino acid sequence.Comparison of the gB gene nucleotide sequence with that of the ILTV 632 strain,SA2 strain,Throne strain,Yantai strain and Liaoning strain published previously in GenBank,revealed similarity of more than 99%.When compared with ILTV-SA2 strain,ILTV-CG strain had one base deletion of G at 89 nt and one base insertion of A at 102 nt within gB gene,resulting five amino acid frame shift mutation.This study provided foundation for the development of recombinant vaccine against ILTV.