Mechanisms of genomic, genetic, and phenotypic divergence in the Magnaporthaceae

Magnaporthaceae 基因组、遗传和表型分化的机制

• 批准号: 93324-2010
• 负责人: Kohn, Linda
• 金额: $ 4.44万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=451216
• 关键词: Mechanisms; genomic; genetic; phenotypic; divergence

How do fungal populations adapt to infect new hosts or evolve new species? Either reconstructed statistically from genomic DNA and protein sequences, or observed in real time in the course of experimental evolution in the laboratory, we prove two key Darwinian concepts: natural selection on new variants (mutations) with those conveying adaptation (higher fitness) increasing in frequency in populations, and persistence of adaptive genotypes when hybrids between different adaptations have poorer fitness than their parents. The novel aspect is that we identify the genes in which mutations occur and the effects, in response to any stress we choose, of specific mutations, from the effect of a gene product to all ripple effects throughout the whole genome. Other speciation laboratories study existing species that evolved in events we cannot observe or reconstruct because they occurred millions of years ago. From one cell, in just 3 months, we incited speciation in 12 lab populations of baking/brewing/wine yeast. Using next-generation genome sequencing, population genomics, genetics, and transcriptomics, we have found 12 key mutations in four of the populations adapted to one of two stress environments, high salt or low glucose. Three of these mutations are in global regulators of gene expression with broad ripple effects. These same variants are found in wild vineyard yeast, not just in the lab. We propose to determine their importance in the wild in relation to how yeast uses food to produce energy. We are also using whole genomes to study an important group of plant-disease fungi, including Magnaporthe, cause of blast, the most important disease of rice worldwide, and Gaeumannomyces, cause of take all of wheat and other grains worldwide, including Canada. The objectives are to identify the genes and their variants caused by mutation that have caused diversification in these genera, specifically ability to change hosts and nutritionally exploit different grasses, including turf and cereal species. We hope to increase our ability to improve these crop species and to predict the direction of evolutionary change (in a changing world) in order to better manage disease.

真菌种群如何适应感染新宿主或进化新物种？无论是从基因组 DNA 和蛋白质序列中统计重建，还是在实验室实验进化过程中实时观察，我们证明了两个关键的达尔文概念：对新变异（突变）的自然选择，其中那些传达适应（更高适应度）的频率在群体中增加，以及当不同适应之间的杂交体比其亲代适应度更差时，适应性基因型的持续存在。新颖的方面是，我们识别了发生突变的基因，以及响应我们选择的任何压力的特定突变的影响，从基因产物的影响到整个基因组的所有连锁反应。 其他物种实验室研究现有物种，这些物种是在我们无法观察或重建的事件中进化的，因为它们发生在数百万年前。 在短短 3 个月内，我们从一个细胞中引发了 12 个实验室烘焙/酿造/酿酒酵母群体的物种形成。利用下一代基因组测序、群体基因组学、遗传学和转录组学，我们在适应高盐或低葡萄糖两种压力环境之一的四个群体中发现了 12 个关键突变。其中三个突变位于基因表达的全局调节因子中，具有广泛的连锁反应。这些相同的变体也存在于野生葡萄园酵母中，而不仅仅是在实验室中。 我们建议确定它们在野外对于酵母如何利用食物产生能量的重要性。 我们还利用全基因组来研究一组重要的植物病害真菌，包括稻瘟病菌（引起稻瘟病，世界范围内最重要的水稻病害）和全能酵母菌（引起世界范围内所有小麦和其他谷物（包括加拿大）的病害）。 目的是确定由突变引起的基因及其变异，这些变异导致这些属的多样化，特别是改变宿主和营养利用不同草类（包括草皮和谷物物种）的能力。 我们希望提高改进这些作物品种和预测进化变化方向（在不断变化的世界中）的能力，以便更好地控制疾病。