by Merry Youle — A dou­ble stranded RNA (dsRNA) vi­ral genome, in­tro­duced into a host cell, is met by for­mi­da­ble host de­fenses. The very pres­ence of dsRNA in a eu­kary­otic or prokary­otic cell an­nounces a vi­ral in­fec­tion and elic­its ef­fec­tive re­sponses, rang­ing from si­lenc­ing of the vi­ral mR­NAs to apop­to­sis. De­spite that, there are suc­cess­ful dsRNA viruses through­out the bios­phere. By 2000, eight fam­i­lies with close to 200 "species" were known...