Department of Biology, University of Toronto Mississauga, Mississauga, Canada.
Environ Microbiol. 2012 Sep;14(9):2253-71. doi: 10.1111/j.1462-2920.2012.02706.x. Epub 2012 Feb 23.
Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560 kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies will provide keys to unlocking our understanding of algal virus ecology specifically, and aquatic ecosystems generally.
由于真核藻类病毒的多样性令人难以置信，因此很少对其生态学进行全面概括。这些专性寄生虫感染了一系列藻类，其多样性可以通过考虑到从具有 ssRNA 基因组的小颗粒到具有 560kb dsDNA 基因组的更大颗粒的分离物来说明。分子研究还提供了有关其多样性的线索，尤其是考虑到环境中藻类病毒的遗传特征很少与培养的病毒匹配。藻类病毒生态学中出现的一个普遍概念是，藻类病毒非常宿主特异性，大多数仅感染其宿主的某些菌株；除了褐藻病毒外，缺乏种间感染性的证据。尽管一些宿主-病毒系统表现出繁荣-萧条的波动，但种内感染性的复杂模式会导致宿主-病毒共存，从而使病毒在宿主种群动态中的作用变得模糊。在种群动态的框架内，宿主密度依赖性是一种重要现象，它会影响自然界中病毒的丰度。不同病毒的可变爆发大小也会影响它们的丰度，并允许对不同的生活策略进行推测，但由于藻类病毒生态学中常有例外情况，因此生活策略的概括可能不适用于广泛的情况。病毒季节性和持久性的知识差距正在开始缩小，对环境储库和病毒弹性的研究可能会回答有关病毒年度重现的问题。对藻类死亡率的研究表明，病毒通常是重要的致死因子，这强化了它们在生态学中的相关性的概念，而观察到病毒与宿主相互作用的惊人方式突出表明了我们理解的不成熟。考虑到仅仅二十年前藻类病毒几乎不被承认，最近的进展使人们乐观地认为，未来的研究将为我们理解藻类病毒生态学提供关键，特别是为水生生态系统提供关键。
