Abstract
Changes in polyamines and DNA concentrations in the midgut epithelium of the silkworm infected with a densonucleosis virus (Bombyx DNV) were investigated. Three kinds of polyamines, spermidine, putrescine and spermine, were detected in the midgut epithelia of both infected and healthy silkworms. However, the ratio of these polyamines was somewhat different from that of Bombyx DNV. In the DNV-infected midgut, lower accumulation of spermidine and putrescine, and lower spermidine/spermine ratio were observed as early as 24 hr after DNV inoculation as compared to healthy midgut. DNA concentrations in DNV-infected midguts fluctuated considerably during the course of DNV infection, but the pattern was rather constant as compared to those of healthy ones. These results suggest that infection with Bombyx DNV rapidly affects the physiological condition of host cells, and interferes with normal growth and/or the proliferation of cells.
