Introns, nested introns and intron encoded proteins in the mitochondrial genomes of fungi.

真菌线粒体基因组中的内含子、嵌套内含子和内含子编码蛋白质。

• 批准号: RGPIN-2020-05332
• 负责人: Hausner, Georg
• 金额: $ 3.06万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=760961
• 关键词: Introns; nested; introns; intron; encoded

Many species of Ophiostoma, Grosmannia and Ceratocystis are vectored by insects such as bark beetles, and these fungi are commonly known as blue-stain fungi as they discolour lumber, thus reducing the economic value of the wood. These fungi are also referred to as the ophiostomatoid fungi; and, this group includes tree pathogens such as the causative agents of Dutch Elm Disease or Oak wilt. This research program focuses in part on the taxonomy and evolution of blue-stain fungi. Characterizing mitochondrial genomes of blue-stain fungi is part of the long-term objectives of this proposal. The more immediate goals are to understand the origin and persistence of mobile genetic elements within fungal mitochondrial genomes (mtDNA) and to examine the implications these elements have on mtDNA stability and potentially on the virulence of these tree pathogens. The proposed work over the next five years will focus on characterizing the mitochondrial genomes of Ophiostoma ulmi and related species such as O. novo-ulmi, O. himal-ulmi and species related to the O. ulmi complex. The relative low cost and speed of next generation sequencing allows for sequencing of mtDNAs from many ophiostomatoid fungi, and comparative analysis of the resulting data will provide a resource for possible identifying inter-specific markers for identification of economically important fungi. Also comparing the mtDNA of closely related species should reveal the impact of mobile elements such as mobile introns (group I and group II introns) on mtDNA genome evolution. Sometimes these mobile introns can insert into other introns, forming nested intron arrangements. To understand how these complex introns are actually processed within the mitochondria the RNA will be sequenced to recover splicing intermediates. These fungi are strict aerobic organisms, therefore functional mitochondria are essential. Mobile introns have been associated with mitochondrial defects and these elements contribute towards the size and the architecture of fungal mitochondrial genomes. This work may elucidate the splicing pathways for nested introns and possibly reveal elements that could serve as regulatory elements. It has recently been suggested the group I intron splicing could be a target for therapeutic applications with regards to human pathogenic fungi or potential fungicides for plant pathogens. Gaining knowledge about mtDNA intron splicing and the impact of mobile introns on fungal mtDNAs could be valuable information when developing strategies to identify and control plant pathogens, such as members of the blue-stain fungi. In addition these mobile elements frequently encode site-specific DNA cutting enzymes, so called homing endonucleases. These enzymes have application in genomics and biotechnology as genome editing reagents.

许多种类的Ophiostoma，Grosmannia和Ceratocystis是由昆虫如树皮甲虫传播的，这些真菌通常被称为蓝变真菌，因为它们使木材变色，从而降低了木材的经济价值。这些真菌也被称为ophiostomatoid真菌;并且，这一组包括树木病原体，例如荷兰榆树病或橡树枯萎病的病原体。该研究项目的部分重点是蓝变真菌的分类和进化。蓝变真菌的线粒体基因组特征是该提案的长期目标的一部分。更直接的目标是了解真菌线粒体基因组（mtDNA）中移动的遗传元件的起源和持久性，并研究这些元件对mtDNA稳定性的影响，并可能对这些树木病原体的毒力。未来五年的工作将集中在描述Ophiostoma ulmi和相关物种的线粒体基因组，如O。novo-ulmi、新乌木O. himal-ulmi和与O. Ulmi复合体下一代测序的相对低的成本和速度允许从许多ophiostomatoid真菌的mtDNA测序，和所得数据的比较分析将提供一个资源，为可能的识别种间标记，以确定经济上重要的真菌。此外，比较密切相关物种的mtDNA应该揭示移动的元素，如移动的内含子（第I组和第II组内含子）对mtDNA基因组进化的影响。有时这些移动的内含子可以插入到其他内含子中，形成嵌套的内含子排列。为了了解这些复杂的内含子在线粒体内是如何加工的，将对RNA进行测序以回收剪接中间体。这些真菌是严格的需氧生物，因此功能性线粒体是必不可少的。移动的内含子与线粒体缺陷相关，这些元件对真菌线粒体基因组的大小和结构有贡献。这项工作可能阐明剪接途径的嵌套内含子，并可能揭示元件，可以作为调控元件。最近有人提出，I组内含子剪接可能是人类病原真菌或植物病原体潜在杀真菌剂的治疗应用的靶标。获得有关mtDNA内含子剪接和移动的内含子对真菌mtDNA的影响的知识，可能是有价值的信息时，制定战略，以确定和控制植物病原体，如成员的蓝变真菌。此外，这些移动的元件经常编码位点特异性DNA切割酶，所谓的归巢核酸内切酶。这些酶作为基因组编辑试剂在基因组学和生物技术中具有应用。