水稻基因组内源性矮牵牛脉明病毒序列分析

发布时间：2018-06-30 00:09

本文选题：ePVCVL + 基因组化石　；参考：《中国农业科学院》2017年博士后论文

【摘要】：内源性副逆转录病毒序列(EPRV)存在于各种开花植物基因组中,但目前为止还没有EPRV影响植物基因的功能和进化的直接证据和实例。先前深入研究了 eRTBVL序列整合的分子机制,发现病毒序列通过非同源重组的方式优先插入到水稻基因组的DNA双链断链热点区域。eRTBVL的整合历史和进化过程是发生在水稻驯化之前,整合和进化伴随着水稻祖先的物种形成和生态型的分化扩散。通过基因组序列搜索,又发现了一种新的水稻EPRV家族,类似于矮牵牛脉明病毒序列(ePVCVL)。不同种类的病毒感染宿主后在细胞中的相互作用会影响病毒在基因组的适应性。内源性病毒序列,例如endogenous pararetroviruses(PRVs),是由于病毒序列的垂直遗传,从而整合到了宿主基因组。PRVs病毒作为基因组的化石,被认为是有价值的古基因组学数据,是研究病毒-病毒相互作用的长期进化的动力。所有现存的PRVs在宿主的寄生生命周期里都被认为是自主性的物种。复合型的非自主性PRV物种在病毒活性上是带有结构缺陷的,它们能频繁地感染禾本科宿主,并通过病毒-病毒的相互作用而相互适应。本研究通过禾本科基因组的内源性PRVs病毒的古基因组学数据分析,揭示了这些非自主性的PRV物种与自主性的PRV在寄生关系里产生了相互作用,或者它们是互利的合作伙伴关系。这种合作伙伴关系,在两个伙伴病毒之间的基因间隔区,非编码调控序列(NRSs)的共享已经建立,通过NRSs的趋同性进一步被保持和改变。值得注意的是,研究者发现频繁的区域特异性重组是NRSs趋同性的主要机制。本研究的结果是,从远古病毒的DNA记录获得的,研究表明在相同宿主的不同种病毒之间通过NRSs的交换,PRVs产生了适应性;进一步的实验表明宿主内部NRS是相互作用的,在基因组内部或病毒性病原体种群之间可能是重要的。
[Abstract]:Endogenous paraportrovirus sequences (EPRV) exist in the genomes of various flowering plants, but so far there is no direct evidence and examples of EPRV affecting the function and evolution of plant genes. Previously, the molecular mechanism of eRTBVL sequence integration was studied. It was found that the integration history and evolution of eRTBVL preferentially inserted into the hot spot region of rice genome by non-homologous recombination. ERTBVL occurred before rice acclimation. Integration and evolution are accompanied by species formation and ecotype diffusion of rice ancestors. A new rice EPRV family, similar to petunia virulence virus sequence (ePVCVL), was found by genomic sequence search. The interaction of different viruses in the host after infection will affect the adaptability of the virus in the genome. Endogenous viral sequences, such as endogenous pararetroviruses (PRVs, are integrated into the host genome. PRVs as fossils of the genome because of vertical inheritance of the virus sequences, and are considered valuable paleogenomics data. It is the driving force of long-term evolution of virus-virus interaction. All existing PRVs are considered autonomous species during the host's parasitic life cycle. Complex non-autonomous PRV species have structural defects in their viral activity and they can frequently infect gramineous hosts and adapt to each other through the virus-virus interaction. Based on the analysis of the paleogenomics data of endogenous PRVs in Gramineae, this study reveals that these non-autonomous PRV species interact with autonomous PRVs in parasitic relationships, or that they are mutually beneficial partnerships. This partnership, the sharing of non-coding regulatory sequences (NRSs) between the two partner viruses, has been established and further maintained and changed through the convergence of NRSs. It is worth noting that frequent region-specific recombination is the main mechanism of NRSs convergence. The results of this study were obtained from the DNA records of ancient viruses, which showed that there was adaptability between different viruses of the same host through the exchange of NRSs, and further experiments showed that NRS interacted with each other within the host. It may be important within the genome or between populations of viral pathogens.
【学位授予单位】：中国农业科学院
【学位级别】：博士后
【学位授予年份】：2017
【分类号】：Q943.2

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