【摘要】 依据基因组中的单核苷酸多态性(SNPs)位点对不同来源家蚕核型多角体病毒(Bm NPV)进行地理株系溯源,有利于Bm NPV的分子流行病学研究以及对病害流行的预防性控制。采用霰弹法对Bm NPV重庆分离株CQ1进行全基因组测序,获得了1 052条reads序列,测序深度为3.5倍,覆盖基因组95%以上的区域。采用生物信息学方法,将这些序列与Bm NPV日本分离株T3的基因组序列进行比对分析,在2个株系间共鉴定获得400个候选SNPs。与T3株基因组唯一位点匹配的386个SNPs中,有77%的SNPs属于转换,23%的SNPs属于颠换;15个SNPs位于基因间区,其余都分布在基因编码区;115个非同义SNPs(c SNPs)分布于67个基因的编码序列中,其中11个基因有至少3个非同义SNPs,例如CQ1分离株的非必需基因orf74有5个非同义SNPs。结构预测显示,CQ1分离株的几丁质酶基因中3个非同义SNPs引起变化的氨基酸位点均位于几丁质酶的三维结构表面。研究结果表明,Bm NPV CQ1和Bm NPV T3株系之间存在丰富的单核苷酸多态性。更多还原

【Abstract】 Investigating the geographical origin of Bm NPV from different sources based on single nucleotide polymorphisms( SNPs) would facilitate the molecular epidemiologic study and preventive control of disease epidemic of Bm NPV.In this study,Bm NPV isolate CQ1 from Chongqing,China was sequenced with shot-gun strategy. The total lengths of assembled contigs was nearly 3. 5 fold genome equivalent of Bm NPV and covered more than 95% of the whole genome of Bm NPV T3 strain from Japan. Based on bioinformatic analysis,400 candidate SNPs were discovered in Bm NPV CQ1 isolate compared with genome sequence of Bm NPV T3 strain,386 of which were located to unique positions of Bm NPV T3 genome. 77% of SNPs were transitions and 23% of SNPs were transversions. Fifteen SNPs were located in intergenic regions,the rest of them were distributed on coding sequences. 115 SNPs were asynonymous and distributed in 67 coding sequences. Eleven genes owned at least three asynonymous SNPs. As a non-essential gene,orf74 of Bm NPV CQ1 isolate possesses five asynonymous SNPs. The three changed amino acid of chitinase resulted from asynonymous SNPs were predicted to localize on the surface of 3-dimensional structure. These findings indicate that abundant polymorphisms exist between Bm NPV CQ1 isolate and T3 strain.更多还原