Abstract
Drosophila Kc cells contain a series of RNA fragments ranging in size from 980 to 4600 bp. The fragments copurify with a virus-like nucleoprotein particle which has a density of 1.384 g/cm3 and is a 62 nm diameter icosahedron. There are 11-13 double stranded RNAs in the particles; they are not homologous with either cultured cell or embryo genomic DNA. The particle also contains a minimum of seven polypeptides, three of which are major, and all of which continue to be synthesized in Kc cells in heat shock when normal cellular protein synthesis is shut down. This virus-like particle occurs in large enough amounts in Kc cells to confuse molecular and physiological studies, however the cells continue to multiply in its presence.