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: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=475234
• 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.

真菌群体如何适应感染新宿主或进化新物种？无论是从基因组DNA和蛋白质序列中重建统计数据，还是在实验室的实验进化过程中实时观察，我们都证明了达尔文的两个关键概念：自然选择对新变异（突变）的选择，即那些传递适应性（更高适应度）的变异在种群中出现的频率增加；当不同适应度之间的杂种比其亲本适应度差时，适应性基因型的持久性。新颖的方面是，我们可以识别出发生突变的基因，以及在我们选择的任何压力下，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。其他物种形成实验室研究的是在我们无法观察或重建的事件中进化的现有物种，因为它们发生在数百万年前。在短短3个月的时间里，我们从一个细胞中激发了12个烘焙/酿造/葡萄酒酵母的实验室种群的物种形成。利用下一代基因组测序、种群基因组学、遗传学和转录组学，我们在适应高盐或低葡萄糖两种应激环境之一的四个种群中发现了12个关键突变。其中三个突变发生在基因表达的全球调控中，具有广泛的连锁反应。这些相同的变异不仅存在于实验室，也存在于野生葡萄园酵母中。我们建议确定它们在野外与酵母如何利用食物产生能量有关的重要性。我们也在使用全基因组来研究一组重要的植物病害真菌，包括稻瘟病的致病真菌Magnaporthe，稻瘟病是世界上最重要的水稻病害，以及导致世界上所有小麦和其他谷物（包括加拿大）病害的Gaeumannomyces。目标是确定由突变引起的基因及其变异，这些突变导致了这些属的多样化，特别是改变宿主和营养利用不同草的能力，包括草坪和谷类。我们希望提高我们改良这些作物品种的能力，并预测（在不断变化的世界中）进化变化的方向，以便更好地管理疾病。