| Summary: | 碩士 === 國立臺灣大學 === 獸醫學系 === 84 === The cDNA sequences of fusion (F) and hemagglutinin-
neuraminidase (HN) glycoprotein genes of Newcastle disease
virus (NDV) were deterimined from a viscerotropic velogenic
strains (Taiwan/95) isolated from an epidemic in 1995. Open
reading frames, assumed to encode the F0 and HN glycoproteins,
were 553 and 571 amino acids long, respectively. Comparisons of
the two sequences with other published NDV strains revealed
that these two glycoproteins exhibit molecular features
characteristic of virulent strains. There were two pairs of
basic amino acids (RRQKR) at the cleavage site of F0 and a
phenylalanine residue occurs at the N terminus of F1 cleavage
fragment. The amino acid sequences at the C terminus of the HN
glycoprotein were non-extended indicating no cleavage is needed
for activation. Nucleotide and amino acid sequences were
compared with another local isolated (strain Taiwan/69) and 85%
and 91% sequence identity were found. The result indicated
distinguished strain variation among 26 years interval in the
same geographical area. Analysis of the phylogenetic trees
constructed on the basis of the F and HN genes of the American,
Asian and European NDV isolates revealed that Taiwan isolates
were more similar to the Asian and European ones.
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