关键词: 食品安全法, 食品安全法, 食品安全监管机制, 灰色关联度, 政策评估

Abstract: This research aimed at further studying the HN gene of La Sota strain of Newcastle disease virus from the perspective of molecular biology and exploring the genetic variation of NDV La Sota HN gene. Taking laboratory frozen pNDV-HN as a template, Primer 5.0 analysis software was utilized to design a pair of primers according to the sequence of NDV La Sota strain published on the GenBank. HN gene was amplified and cloned to the pMD18-T vector. The recombinant plasmid pMD-NDV-HN was identified by restriction enzyme analysis, PCR identification and nucleotide sequence analysis. Boinformatics software was used to analyze La Sota strain of Newcastle disease virus HN gene with respect to phylogenetic tree analysis, amino acid sequence homology analysis, amino acid sequence homology analysis, glycosylation sites, transmembrane protein structure analysis and prediction of phosphorylation sites. The sequencing results revealed that HN gene was 1743 bp and the length of the open reading frame(ORF) was 1716 bp, encoding 571 amino acids. Bioinformatics showed that: HN gene had six potential glycosylation sites, no fifth site(508 - 510 aa), and 12 cysteine residues, the 123 cysteine residues were replaced by tryptophan residues. The protein La Sota strain HN gene encoded 29 serine, 10 tyrosine and 16 threonine, and those may become protein kinase phosphorylation sites. The highest nucleotide sequence homology and amino acid homology of NDV La Sota strain HN gene to NDV La Sota strain HN gene can reach 99%, indicating that HN gene conserved in higher species. The study will lay a foundation for the molecular virology research of NDV.