摘要:诺如病毒于1972年被发现以来,在世界各地每年都有因感染诺如病毒导致急性肠胃炎暴发的案例,对抗诺如病毒已经成了一个世界性的问题。诺如病毒以其具有传播范围广、感染性程度高、致病剂量低、传播媒介多样以及抵抗外界不理想条件能力强等特点,难以找到有效地药物及疫苗来治疗和预防它。本课题通过对GI、GII型诺如病毒VP1基因序列的收集,按照病毒株之间不同的特点进行归类,从中选出适当的代表株,将代表株与其它诺如病毒株VP1基因序列进行比对,在代表株与其它病毒株之间构建系统发育树以及遗传距离和同源性的计算,将所得到的系统发育树和通过计算得出的遗传距离和同源性进行分析,最终得出GI、GII型诺如病毒的进化规律。希望能对治疗和预防诺如病毒的药物和疫苗的研制有所帮助。22664 毕业论文关键词: 诺如病毒;VP1基因序列;系统发育树;遗传距离;同源性
Characteristics Analysis and Evolutionary Mechanism of the Genome of Norovirus GI、GII-type Epidemic Strain
Abstract:Since norovirus was discovered in 1972, the cases of acute gastroenteritis because of the norovirus happens around the world every year. Against norovirus has become a worldwide problem.It is difficult to find effective drugs and vaccines for the treatment and prevention of norovirus because of its spread wide,high degree of infectivity, pathogenicity low dose, perse media and strong resistance to external conditions. The issue eventually gets the GI, GII norovirus-type law of evolution of the virus through the collection of GI, GII Norovirus VP1 gene sequences, classifying of virus strains according to different characteristics between the virus strains, choosing the appropriate representative strains, comparing VP1 gene sequence of representative strains with others, constructing phylogenetic tree between the representative strains and others, calculating of genetic distance and homology between the representative strains and others, analysing phylogenetic tree and genetic distance and homology. It is hope that the conclusion of the issue will help to develop the drugs and vaccines of the treatment and prevention of norovirus
Key words: Norovirus; VP1 gene sequences; Phylogenetic tree; Genetic distance; Homology
目 录
1 绪论 1
1.1诺如病毒概述 1
1.2诺如病毒暴发案例 1
1.3诺如病毒感染案例的特征 2
1.4诺如病毒的基因组 3
1.5诺如病毒的遗传多样性 3
1.6诺如病毒的进化 3
1.7系统发生树 4
1.8算法 4
1.9本课题的研究目的和意义 5
2 材料与方法 6
2.1 实验材料 6
2.2 实验仪器与设备 6
2.3 实验方法 6
2.3.1诺如病毒流行株基因组序列收集 6
2.3.2基因组序列的分类与代表株的选择 6
2.3.3基因组序列分析与系统发育树构建 6
2.3.4遗传距离与同源性的计算 13
2.3.5系统发育树的分析 14
3 结果与讨论 15
3.1诺如病毒VP1基因的收集结果 15
3.2诺如病毒VP1基因序列的归类与特点分析 18
3.2.1报道年份分布特点 18
3.2.2诺如病毒地点分布特点 19
3.1.3诺如病毒VP1基因型及其亚型分布特点 20
3.2诺如病毒代表株的选型 21
3.3基因序列比对与系统发育树的构建及分析 21
3.3.1与同时、不同地点报道病毒株之间的比对结果 21