一株番鸭源N6亚型禽流感病毒神经氨酸酶基因的克隆及序列分析

PHYLOGENETIC ANALYSIS OF NEURAMINIDASE GENE OF AVIAN INFLUENZA VIRUS ISOLATED FROM MUSCOVY DUCK

为了丰富水禽源流感病毒神经氨酸酶基因（NA）的分子流行病学资料，通过对2008年分离自福建省某种番鸭1株罕见的H6N6亚型禽流感病毒（Avian influenza virus，AIV）NA基因进行克隆分析，发现该毒株NA基因全长为1431bp，开放阅读框为1380bp（19～1398），其中从第175～207位缺失33个核苷酸：其编码459个氨基酸，颈部存在有11个氨基酸的缺失（TNSTTTIINNN），为在N6亚型神经氨酸酶基因中首次报道有颈部缺失。该NA基因和我国分离的A／duck／Eastern China／01／2007（H4N6）NA基因的核苷酸同源性最高，达97．1％，并处在同一遗传进化分支上；与其它H6N6亚型AIV分离株NA基因的同源性均较低，同源性处在78．3％到79．6％之间，相互之间遗传关系较远，其它H6N6亚型AIVNA基因在遗传进化上呈独立进化分支。

The neuraminidase （ NA ） gene of a H6N6 subtype Avian influenza virus （ AIV ） isolated in 2008 from domestic Muscovy duck in Fujian in the southern China was cloned and sequenced. The full-length NA nucleotide was 1 431bp and its open reading frame （ORF） was 1 380 bp located from positions 19 to 1 398. The NA gene also had 33 nucleotides deletion from position 175 to 207 at the N6 gene stalk. Therefore, the ORF encoded 459 amino acids. The nucleotide sequences had the highest similarity with A/duck/Eastern China/01/2007 （ H4N6 ） at 97.1%, suggesting close phylogenetic relationship. However, the N6 gene shared a low similarity with other H6N6 subtype AIVs, ranging from 78.3 % to 79.6 %.