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

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出来的，还是在实验室实验进化过程中实时观察到的，我们证明了两个关键的达尔文主义概念：对新变种(突变)的自然选择和当不同适应之间的杂交种的适合度比它们的亲本更差时，对那些传达适应(更高适应度)的新变种(突变)的自然选择，以及当不同适应之间的杂交种的适应度比它们的双亲更差时，适应基因型的持久性。新的方面是，我们识别发生突变的基因，以及作为对我们选择的任何压力的反应，特定突变的影响，从基因产物的影响到整个基因组的所有涟漪效应。其他物种形成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，我们从一个细胞中激发了12个烘焙/酿造/葡萄酒酵母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，我们在四个适应两种应激环境之一的种群中发现了12个关键突变，高盐或低糖。这些突变中有三个存在于基因表达的全球调控中，具有广泛的涟漪效应。在野生葡萄园酵母中也发现了这些相同的变种，而不仅仅是在实验室。我们建议根据酵母如何利用食物产生能量来确定它们在野外的重要性。我们还在利用全基因组研究一组重要的植物病害真菌，包括引起稻瘟病的稻瘟病(Magnaporthe)，全世界最重要的水稻病害，以及导致小麦和其他谷物在世界范围内(包括加拿大)枯萎的盖曼霉菌(Gaeumannmyces)。目的是确定导致这些属多样化的基因及其变异，特别是改变寄主和营养利用不同草本植物的能力，包括草皮和谷物物种。我们希望提高我们改进这些作物物种的能力，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。

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.