Effect of coinheritance on host-pathogen coevolution

描述(申请人提供)：拟议研究的总体目标是发展必要的遗传理论，以了解宿主和微生物基因组的共同传播模式如何影响共生细菌和病原菌与其宿主的共同进化。我们的方法是新颖的，因为它将为模拟单个基因组内核基因组合的遗传而开发的理论扩展到跨两个基因组的基因组合，即寄主和病原体的基因组合。当应用于核和线粒体基因组合时，该方法成功地预测了从线粒体到核的功能基因转移的频率：功能基因的基因组间转移在近亲繁殖物种中发生的可能性是异交物种的十倍。交配系统对基因转移产生这种影响的原因是，与基因独立遗传的交配系统相比，线粒体和核基因一起遗传的交配系统允许自然选择对基因组合起更有效的作用。尽管线粒体像一些内共生体一样完全垂直传播，但类似的效应预计会在只有部分垂直传播的系统中表现出来，我们将发展这一更一般的理论。两位点下降理论量化了相同或不同基因组中基因组合的共同遗传，确定了每个物种中基因进化轨迹的连接程度。这决定了宿主与病原体的联系是朝着增强毒力还是朝着良性共生发展。 项目简介：传播速度的变化从根本上改变了宿主及其病原体的遗传协同进化，并促进了新疾病的出现。虽然在一代宿主中感染宿主的传播与疾病流行病学之间的直接联系是众所周知的，但疾病从一代宿主传播到下一代宿主的遗传后果却鲜为人知。这一建议将发展遗传学理论，以解决宿主基因和宿主病原体的共同遗传如何影响疾病毒力的进化。

DESCRIPTION (provided by applicant): The overall goal of the proposed research is to develop the genetic theory necessary for understanding how patterns of co-transmission of host and microbial genomes affect the co-evolution of symbiotic and pathogenic bacteria with their hosts. Our approach is novel in that it extends theory developed for modeling the inheritance of nuclear gene combinations within single genomes to gene combinations across two genomes, those of host and pathogen. When applied to nuclear and mitochondrial gene combinations, this approach successfully predicted the frequency of functional gene transfer from the mitochondria to the nucleus: inter-genomic transfer of functional genes is ten-fold more likely to occur in inbreeding species than in outcrossing species. The reason for this effect of mating system on gene transfer is that mating systems, where mitochondrial and nuclear genes are inherited together, allow natural selection to act more effectively on gene combinations than mating systems where the genes are inherited independently. Although mitochondria are wholly vertically transmitted like some endosymbionts, similar effects are expected to be manifest in systems with only partial vertical transmission and we will develop this more general theory. Two-locus descent theory quantifies the coinheritance of gene combinations in the same or different genomes, determining the degree to which the evolutionary trajectories of genes in each species are conjoined. This determines whether a host-pathogen association will develop toward enhanced virulence or toward benign symbiosis. Project Narrative: Change in the dispersal rates fundamentally change the genetic coevolution both hosts and their pathogens and contribute to the emergence of new diseases. Although a direct link between dispersal of infected hosts and disease epidemiology within a single host generation is well known, the genetic consequences of disease transmission from one generation of hosts to the next is much more poorly understood. This proposal will develop genetic theory for addressing how the co-inheritance of host genes and host pathogens affects the evolution of disease virulence.