| Summary: | 碩士 === 國立臺灣大學 === 獸醫學系 === 85 === Restriction site analysis and direct sequencing were applied to explore
the variety of Newcastle disease viruses isolated from Taiwan. A 1,349 bp
fragment of the F gene was amplified by reverse transcription-polymerase
chain reaction (RT-PCR) with the primers, Fd3 and Fd5. PCR products were
cleaved by three restriction endonucleases, Hinf I, BstO I and Rsa I and
the positions of the restriction sites were mapped. Restriction site
analysis showed that four patterns of restriction sites could be found
in seven Taiwan isolates. The restriction sites of the chicken isolates from
either before or during the 1995 outbreak were all the same, and the number
of the restriction sites of Hinf I, BstO I and Rsa I were 4, 2 and 4,
respectively. An additional restriction site of Hinf I was found in the
owl isolate from the same outbreak, but the isolate from 1991 only had
3 restriction sites of Rsa I. The isolate from 1969 showed the variation
most. The 1969 isolate was found 6 unique restriction sites. The number
of the different restriction sites of Hinf I, BstO I and Rsa I were 1, 4
and 1, respectively. The F gene of the owl isolate was sequenced by RT-PCR and
direct sequencing. A 1,624 bp sequence was obtained. The deduced amino
acid sequence showed the character of virulent strains; the sequence
of the cleavage site for the protease was 112R-R-Q-K-R-F117. According
to the phylogenic analysis, the owl isolate was most close to the
isolate from the same outbreak, TAIWAN/95.
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