Infection of a susceptible/nonsusceptible mosaic silkworm, Bombyx mori, with densonucleosis virus type-2 is not lethal
Abe, H.; Kobayashi, K.; Shimada, T.; Yokoyama, T.; Maeda, S.; Hamano, K.; Oshiki, T.; Kobayashi, M.
Journal of Sericultural Science of Japan 62(5): 367-375
Bombyx mori densonucleosis virus type-2 (DNV-2) multiplies in the nuclei of the midgut epithelium columnar cells of the silkworm, B. mori. The susceptibility of B. mori to DNV-2 is controlled by the recessive gene, nsd-2. Certain silkworm strains are genetically nonsusceptible (completely resistant) to DNV-2. Mosaic silkworm larvae with susceptible(nsd-2/+) and nonsusceptible(nsd-2/nsd-2) midgut cells were produced using the hereditary mosaic strain (mo). Seventeen newly-ecdysed 2nd instar mosaic larvae were fed with DNV-2 and the infection was monitored using polymerase chain reaction (PCR) to detect DNV-2 in the feces. DNV-2 multiplied continually in five of the larvae, however, they survived and grew showing no outer symptoms of virus infection. Immunoperoxidase and Feulgen light-green staining of larval body sections indicated that DNV-2 infection only occurred in the regions with susceptible cells(nsd-2/+). These results indicate that, DNV-2 infection itself is not lethal.