Diverse responses of the bivalve-kiving dinoflagellate Heterocapsa circularisquama to infection by a single-stranded RNA virus
Diverse responses of the bivalve-kiving dinoflagellate Heterocapsa circularisquama to infection by a single-stranded RNA virus
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DOI：
10.1128/aem.02190-07
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发表时间：
2008-05-01
影响因子：
4.4
通讯作者：
Nagasaki, Keizo
中科院分区：
文献类型：
--
作者：
Mizumoto, Hiroyuki;Tomaru, Yuji;Nagasaki, Keizo
病毒被认为是浮游植物的重要病原体。通常，它们只感染一种藻类，而且它们的感染通常是高度菌株特异性的。然而，该菌株特异性的详细分子背景及其生态意义还没有被充分了解。在这里，我们研究了病毒RNA积累和病毒诱导的细胞裂解的时间变化，使用了一种正在形成水华的甲藻异形鞭毛虫及其单链RNA病毒HcRNAV。我们观察到至少三种宿主对病毒接种的反应模式：敏感、抗性和延迟裂解。在敏感反应中，宿主细胞培养对病毒RNA复制是允许的，并观察到明显的细胞裂解；相反，抗性细胞培养对病毒RNA复制是不允许的，不裂解。在延迟裂解反应中，虽然发生了病毒RNA复制，但病毒诱导的细胞裂解微弱且明显延迟。此外，接种后12天释放到培养上清液中的感染性病毒颗粒数量与敏感株相当。通过进一步分析，少数菌株被鉴定为延迟裂解菌株的变种。这些观察结果表明，圆环毛虫对HcRNAV感染的反应是高度多样化的。
Viruses are believed to be significant pathogens for phytoplankton. Usually, they infect a single algal species, and often their infection is highly strain specific. However, the detailed molecular background of the strain specificity and its ecological significance have not been sufficiently understood. Here, we investigated the temporal changes in viral RNA accumulation and virus-induced cell lysis using a bloom-forming dinoflagellate Heterocapsa circularisquama and its single-stranded RNA virus, HcRNAV. We observed at least three host response patterns to virus inoculation: sensitive, resistant, and delayed lysis. In the sensitive response, the host cell culture was permissive for viral RNA replication and apparent cell lysis was observed; in contrast, resistant cell culture was nonpermissive for viral RNA replication and not lysed. In the delayed-lysis response, although viral RNA replication occurred, virus-induced cell lysis was faint and remarkably delayed. In addition, the number of infectious virus particles released to the culture supernatant at 12 days postinoculation was comparable to that of the sensitive strain. By further analysis, a few strains were characterized as variants of the delayed-lysis strain. These observations indicate that the response of H. circularisquama to HcRNAV infection is highly diverse.