GENETIC VARIATION AMONG DENGUE VIRUSES

登革热病毒之间的基因变异

• 批准号: 4688567
• 负责人: C J LAI
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/4688567
• 关键词: antibody neutralization test; biological polymorphism; communicable diseases; dengue; dengue virus; gel electrophoresis; genetic manipulation; genetic mapping; genetic recombination; genetic strain; hemorrhagic fever; molecular cloning; nucleic acid sequence; plasmids; virus RNA; virus classification; virus genetics

The dengue virus family contains 4 distinct serotypes that are distinguishable by virus neutralization. Among the dengue group the type 2 virus is most frequently involved in hemorrhagic fever, a severe and often fatal form of dengue disease. There is considerable polymorphism among type 2 viruses as indicated by variation in oligonucleotide fingerprints and this variation has a geographic distribution in that specific patterns are limited to specific localities. Efforts are now underway to study genetic variation of dengue viruses by molecular cloning and nucleotide sequencing. Dengue 2 (strain PR159) was chosen for sequence comparison with dengue 4 that is also being cloned and sequenced in our laboratory. Dengue 2 genomic RNA was purified and transcribed into RNA-cDNA hybrids for direct cloning in the pBR322 vector according to the procedure established for dengue 4. Analysis of plasmid DNA after Pst I digestion on agarose gel showed that a majority of recombinant plasmids contained DNA inserts ranging from 500-4,000 base pairs in length. Recombinants with the largest inserts (2,000 base-pairs or more) were chosen for mapping the full-length genomic sequence. For this purpose we took advantage of the genetic homology that exists between dengue virus type 2 and type 4. Radiolabeled probes prepared from cloned DNA segments of dengue 4 at various map positions were used for initial mapping and screening of dengue 2 inserts. Thus far, more than one-half of the dengue 2 genomic sequences have been cloned and our ultimate goal is to obtain a full-length DNA copy. Complete sequence analysis will be performed in an effort to gain a better understanding of the pattern of virus polymorphism in dengue epidemics and the involvement of different virus strains in dengue hemorrhagic fever.

登革热病毒家族包含 4 种不同的血清型，分别是 可通过病毒中和来区分。 在登革热组中，2型 病毒最常引起出血热，这是一种严重且经常发生的疾病 致命的登革热疾病。 之间存在着相当大的多态性 寡核苷酸指纹变化表明 2 型病毒 并且这种变化具有特定模式的地理分布 仅限于特定地区。 目前正在努力研究中 通过分子克隆和核苷酸进行登革热病毒的遗传变异 测序。 选择登革热 2（PR159 株）进行序列比较 登革热 4 也正在我们的实验室进行克隆和测序。 登革热 2 基因组 RNA 被纯化并转录成 RNA-cDNA 杂交体，用于 根据既定程序直接克隆到 pBR322 载体中 登革热 4. Pst I 琼脂糖凝胶消化后的质粒 DNA 分析 表明大多数重组质粒含有 DNA 插入片段 长度范围为 500-4,000 个碱基对。 最大的重组体 选择插入（2,000 个碱基对或更多）来映射全长 基因组序列。 为此，我们利用了基因 2 型和 4 型登革热病毒之间存在同源性。放射性标记 由登革热 4 的克隆 DNA 片段在不同图谱上制备的探针 位置用于登革热 2 插入片段的初始定位和筛选。 迄今为止，超过一半的登革热2基因组序列已被确定 克隆，我们的最终目标是获得全长 DNA 副本。 完全的 将进行序列分析以获得更好的结果 了解登革热流行病中病毒多态性的模式 登革出血热涉及不同病毒株。