Second Meeting of Society of Evolutionary Studies, Japan (2000), The University of Tokyo
1Laboratory of Ethology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology
2Department of Biology, Division of Natural Sciences, International Christian University
ABSTRACT. Recently, plasmid like double-strand RNA (dsRNA) was found in a variety of insect taxa (Miyazaki et al., 1996). In some ant species, the relationship between dsRNA and host ants is sophisticated: dsRNA increases only in the cytoplasm of reproductive females, usually mated queens in Camponotus yamaokai (Hymenoptera: Formicidae). We could not detect dsRNA from individual virgin queens, males, minor and most of major workers by agarose electrophoresis and ethidium bromide staining. However, all reproductive queens and some major workers had enough amount of dsRNA to detect by the same method. If the cost of dsRNA parasitization is not negligible for the entire ant colony, such relationship may be evolutionarily stable. It seems a compromise for the host ant species, and it is also reasonable for parasitic dsRNA because they could not propagate themselves within males or infertile females.