Creighton University, Department of Medical Microbiology and Immunology, Omaha, NE 68178.
Bowdoin College, Brunswick, ME 04011-8451.
Microbiol Spectr. 2017 Jul;5(4). doi: 10.1128/microbiolspec.FUNK-0051-2016.
The ability of an organism to replicate and segregate its genome with high fidelity is vital to its survival and for the production of future generations. Errors in either of these steps (replication or segregation) can lead to a change in ploidy or chromosome number. While these drastic genome changes can be detrimental to the organism, resulting in decreased fitness, they can also provide increased fitness during periods of stress. A change in ploidy or chromosome number can fundamentally change how a cell senses and responds to its environment. Here, we discuss current ideas in fungal biology that illuminate how eukaryotic genome size variation can impact the organism at a cellular and evolutionary level. One of the most fascinating observations from the past 2 decades of research is that some fungi have evolved the ability to tolerate large genome size changes and generate vast genomic heterogeneity without undergoing canonical meiosis.
生物体具有高度保真的复制和分离其基因组的能力，这对其生存和产生后代至关重要。这两个步骤（复制或分离）中的任何一个错误都可能导致倍性或染色体数目的改变。虽然这些剧烈的基因组变化可能对生物体有害，导致适应性降低，但它们也可以在压力时期提供更高的适应性。倍性或染色体数目的改变可以从根本上改变细胞感知和响应环境的方式。在这里，我们讨论了真菌生物学中的现有观点，这些观点阐明了真核生物基因组大小变化如何在细胞和进化水平上影响生物体。过去 20 年研究中最引人注目的观察之一是，一些真菌已经进化出能够耐受大的基因组大小变化并产生巨大基因组异质性而无需经历经典减数分裂的能力。
