Agaricus bisporus is a commercial mushroom crop susceptible to a disease caused by a complex of viruses known collectively as mushroom virus X (MVX). Symptoms of MVX include bare patches and mushroom cap discolouration (browning) in the fruiting bodies, phenotypes associated with the viruses AbV6 and AbV16, respectively. Limited understanding exists of the localisation and mobilisation of these viruses within the mycelium of A. bisporus. To this end, a non-destructive fluorescence in situ hybridisation (FISH) method was developed for in situ targeting of AbV6 and AbV16 in A. bisporus mycelium. An MVX strain associated with the bare patch disease phenotype revealed predominantly high signal towards the growing edges of cultures when probed for AbV6, with a 'halo-effect' of high signal intensity around putative vacuoles. An MVX strain associated with the browning disease phenotype showed high signal intensities within reticulating networks of hyphae in a highly compartmentalised manner when probed for AbV16. Localisation of the two viruses in MVX-infected cultures appears independent, as both viruses were found in completely discrete areas of the mycelium in differential patterns. FISH detected low level presence of the two viruses, AbV6 and AbV16 in a number of cultures which had tested negative for the viruses by RT-PCR. This suggests that FISH may be more sensitive at detecting viruses at low levels than molecular methods. This study demonstrates that FISH is a powerful tool in the field of mycovirology.

中文翻译：

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在真菌中钓鱼：通过荧光原位杂交观察双孢蘑菇菌丝体中的蘑菇病毒X。

双孢蘑菇是一种商业化的蘑菇作物，易患由多种病毒共同引起的疾病，这些病毒统称为蘑菇病毒X（MVX）。MVX的症状包括子实体中裸露的斑块和蘑菇帽变色（褐变），分别与病毒AbV6和AbV16相关的表型。对这些病毒在双孢曲霉菌丝体内的定位和动员的认识有限。为此，开发了一种非破坏性荧光原位杂交（FISH）方法，用于双孢曲霉菌丝体中AbV6和AbV16的原位靶向。当检测AbV6时，与裸露斑块病表型相关的MVX菌株主要向培养物的生长边缘显示高信号，并在假定的液泡周围具有高信号强度的“晕轮效应”。当检测AbV16时，与褐变病表型相关的MVX菌株以高度分隔的方式在菌丝的网状网络内显示出高信号强度。两种病毒在MVX感染的培养物中的定位似乎是独立的，因为两种病毒都以完全不同的模式在菌丝体的完全离散区域中发现。FISH在许多通过RT-PCR对病毒呈阴性的培养物中检测到两种病毒AbV6和AbV16的低水平存在。这表明FISH在检测低水平病毒方面可能比分子方法更敏感。这项研究表明，FISH是真菌病毒学领域的强大工具。