Cricket Paralysis Virus

Cricket Paralysis Virus (CrPV) was initially discovered in Australian field crickets (Teleogryllus commodus and Teleogryllus oceanicus) by Carl Reinganum and his colleagues at the Victorian Plant Research Institute (Burnley, Melbourne, Australia). The paralytic disease spread rapidly through a breeding colony as well as through a laboratory population causing about 95% mortality. This was the first recorded isolate of the virus and is generally referred to as CrPVvic to distinguish it from subsequent isolates. The spheroidal, non-enveloped virus particles of CrPV are about 27 nm diameter in negatively stained electron micrographs and contain a single piece of positive-sense ssRNA. The virion is composed of 4 capsid proteins with molecular masses generally reported to be 33, 31 and 30 kilodaltons with a minor VP4 protein of about 8 kDa. The particles resemble those of the mammalian picornaviruses but CrPV virions sediment at a faster rate (167 S) than poliovirus particles (158 S) in sucrose rate-zonal gradients and, in isopycnic neutral cesium chloride gradients, CrPV particles are denser than those of poliovirus (1.368 g/cm3 vs 1.340 g/cm3 respectively).