中国生物工程杂志

After comparisons of the sequences of amino acids of HN gene among NDV strains with genotype difference, it was revealed that in strain Ⅶ the sequence of amino acid from 65 to 75 was conservative, while the same fragments in other strains were different from each other. So the fragments of HN gene in strain La Sota, GX-2 and F48E9, which were the representative strains of Ⅱ、Ⅶ、Ⅸ genotype of NDV, were cloned and expressed, while the antigenicities of expressed peptides were assayed by anti-serum. SPF chickens were immunized by each expressed proteins and the antibody titers of different groups were assayed by ELISA. The results showed that there were differences in reactionogenicity in 3 strains. All chickens which were immunized by different expressed proteins were challenged by F48E9, a velogen strain of NDV. Results showed that the protection rate of every expressed protein was different from each other, which illustrated that there were differences of immunogenicity in researched region among 3 strains.