COLLABORATIVE RESEARCH: Genomic consequences of recent and ancient allopolyploidy: a continuum of ages in Tragopogon (Asteraceae)

我们对基因组加倍（多倍体）后基因进化命运的了解，大多是基于几种已有数千年历史的作物和只有几代历史的合成多倍体。本项目将研究一个非常令人惊讶的发现，即同源基因在多倍体化后迅速丢失，而不是沉默或其他调控变化。他们想知道，对于哪些基因或更大的基因组片段优先丢失，是否存在普遍规律。这一点很重要，因为以前的发现是来自合成多倍体和最近的自然多倍体（100年）。植物属Tragopogon（山羊须，向日葵科）提供了一个独特的机会来调查多倍体在不同年龄的自然界中发生的变化。家兔含有二倍体、60-80岁的天然多倍体、合成多倍体和更老的欧亚多倍体。这项研究将研究一个更古老的（80 - 280万年前，mya）天然多倍体，并与最近形成的多倍体进行比较；它还延伸到向日葵家族历史早期的一个古老的多倍体事件（30万年）。基因组加倍（多倍体）产生了许多生命的多样性。所有脊椎动物和开花植物都至少经历过一次古代多倍体，许多作物也是多倍体。因此，阐明多倍体的后果将增强我们对生命多样化的理解，并提供有关作物基因组的基本知识。研究结果将为了解产生大部分生命和大多数作物的过程提供重要的见解。此外，该项目将培养本科生和研究生，以及一名博士后学者，并包括面向公众的外展活动。

Much of what is known about the evolutionary fate of genes following genome doubling (polyploidy) is based on several crops that are thousands of years old and synthetic polyploids that are only several generations old. This project will investigate the very surprising finding that homeologous genes are lost rapidly after polyploidization, rather than being silenced or other regulatory changes. They want to know if there are general rules about which genes or larger pieces of genomes are preferentially lost. This is important because previous findings were from synthetic polyploids and recent natural polyploids (100 years). The plant genus Tragopogon (goatsbeard, in the sunflower family) provides a unique opportunity to investigate changes that occur following polyploidy in nature across a range of ages. Tragopogon contains diploids, natural polyploids that are only 60-80 years old, synthetic polyploids, and older Eurasian polyploids. This study will investigate an older (0.8 -2.8 million years ago, mya) natural polyploid for comparison with the recently formed polyploids; it also extends to an ancient polyploidy event (30 mya) early in the history of the sunflower family. Genome doubling (polyploidy) has generated much of the diversity of life. All vertebrates and flowering plants experienced at least one episode of ancient polyploidy, and many crops are polyploids. Hence, elucidating the consequences of polyploidy will enhance our understanding of the diversification of life and provide fundamental knowledge about crop genomes. Results will provide important insights into the processes that generated much of life and most crops. In addition, the project will train undergraduate and graduate students, and a post-doctoral scholar, as well as including outreach activities to the general public.