ABSTRACT: Algal viruses and cyanophages infect primary producers and have wide-ranging effects upon the food web and biogeochemical cycles. However, little is known about the diversity and distribution of these viruses in freshwater sediments. To address this information gap, sediment core samples were collected from Lake Erie at 4 distinct sites across its 3 basins. PCR primers targeting polB gene sequences of phycodnaviruses and viral capsid assembly genes (g20) of cyanomyoviruses were used to examine the diversity of viral sequences. Additionally, quantitative PCR primers and probes were used to estimate the abundances of algal virus and cyanophage genes at each location. PCR and sequencing of polB and g20 genes revealed diverse assemblages of putative phycodnaviruses and cyanomyoviruses, uncovering novel viral gene sequences and some related to virus genes observed previously in water column samples. Wide abundance ranges of 11 different algal virus (from below detection to 1.43 × 10⁶ gene copies per gram wet sediment) and cyanophage (from below detection to 2.39 × 10⁴ gene copies per gram wet sediment) genes were detected using quantitative PCR. Abundance patterns were spatially variable and distinct for different virus genes. Algal viruses tended to be more abundant in the central and eastern basins, while cyanophages tended to be more abundant in the western basin. The observed diversity of viruses, coupled with the high abundances of several virus genes, suggests that aquatic sediments are an important environmental refugium for phytoplankton viruses and that their geographic patterns may reflect local host abundances.

中文翻译：

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藻类病毒和蓝藻在伊利湖沉积物中有明显的分布

摘要：藻类病毒和蓝藻感染初级生产者，对食物网和生物地球化学循环具有广泛影响。但是，对于这些病毒在淡水沉积物中的多样性和分布知之甚少。为了解决这一信息鸿沟，从伊利湖的3个盆地中的4个不同地点收集了沉积物岩心样品。以藻红病毒的polB基因序列和蓝藻病毒的病毒衣壳装配基因（g20）为靶标的PCR引物被用于检查病毒序列的多样性。此外，定量PCR引物和探针用于估计每个位置的藻类病毒和噬菌体基因的丰度。polB和g20的PCR和测序这些基因揭示了推定的phyddnaviruses和cyanomyoviruses的各种组合，发现了新的病毒基因序列，以及一些先前在水柱样品中观察到的病毒基因相关的基因。丰富的11种藻类病毒（从低于检测值到每克湿沉物1.43×10 ^6个基因拷贝）和蓝噬菌体（从低于检测到2.39×10 ^4个基因拷贝）使用定量PCR检测每克湿沉积物的基因拷贝数）。丰度模式在空间上是可变的，并且对于不同的病毒基因是不同的。藻类病毒在中部和东部盆地趋于更加丰富，而蓝藻在西部盆地趋于更加丰富。观察到的病毒多样性以及几种病毒基因的高丰度表明，水生沉积物是浮游植物病毒的重要环境避难所，它们的地理格局可能反映了当地宿主的丰度。