Development of a Real-Time qPCR Assay for Quantification of Covert Baculovirus Infections in a Major African Crop Pest.
Development of a Real-Time qPCR Assay for Quantification of Covert Baculovirus Infections in a Major African Crop Pest.
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DOI：
10.3390/insects6030746
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发表时间：
2015-08-25
期刊：
影响因子：
3
通讯作者：
Wilson K
中科院分区：
文献类型：
--
作者：
Graham RI;Tummala Y;Rhodes G;Cory JS;Shirras A;Grzywacz D;Wilson K
许多病原体和寄生虫存在于宿主个体和种群中，但没有任何明显的疾病迹象。对于感染鳞翅目宿主的杆状病毒尤其如此，研究表明，在许多物种中，隐蔽的持续病毒感染几乎无处不在。迄今为止，隐蔽病毒的感染强度很少被量化。在这项研究中，我们研究了鳞翅目作物害虫Spodoptera免夜蛾的隐蔽杆状病毒感染动力学。采用5′核酸酶水解（TaqMan）探针，建立了一种实时定量聚合酶链反应（qPCR）方法，对无蹼夜蛾核型多角体病毒（SpexNPV）进行特异性检测和定量。qPCR分析表明，杆状病毒的隐蔽动态在宿主的整个生命周期中变化很大，感染负荷在早期幼虫达到峰值，而在成虫和终末幼虫中最低。成人解剖表明，与预期相反，病毒载量聚集在头部、翅膀和腿部最高，在胸部和腹部最低。这里提出的数据具有广泛的意义，涉及我们对杆状病毒的传播模式和宿主-病原体动力学中隐蔽感染的作用的理解。
Many pathogens and parasites are present in host individuals and populations without any obvious signs of disease. This is particularly true for baculoviruses infecting lepidopteran hosts, where studies have shown that covert persistent viral infections are almost ubiquitous in many species. To date, the infection intensity of covert viruses has rarely been quantified. In this study, we investigated the dynamics of a covert baculovirus infection within the lepidopteran crop pest Spodoptera exempta. A real-time quantitative polymerase chain reaction (qPCR) procedure using a 5' nuclease hydrolysis (TaqMan) probe was developed for specific detection and quantification of Spodoptera exempta nucleopolyhedrovirus (SpexNPV). The qPCR assay indicated that covert baculovirus dynamics varied considerably over the course of the host life-cycle, with infection load peaking in early larval instars and being lowest in adults and final-instar larvae. Adult dissections indicated that, contrary to expectation, viral load aggregation was highest in the head, wings and legs, and lowest in the thorax and abdomen. The data presented here have broad implications relating to our understanding of transmission patterns of baculoviruses and the role of covert infections in host-pathogen dynamics.