Reaper homologue IBM1 in silkworm Bombyx mori induces apoptosis upon baculovirus infection.

In lieu of an adaptive immune system, apoptosis plays a central role in regulating cellular or environmental stimuli in Lepidopteran insect cells during viral infection. Bombyx mori IBM1 gene, a Drosophila Reaper orthologue, is localised in mitochondria and can induce a mitochondrial membrane potential loss. Further, expression of IBM1 is up-regulated rapidly to protect insect cells from viral infection. Ours is the first evidence to indicate that IBM1 could interact with BmNPV IAP2 following B. mori nucleopolyhedrosisvirus (BmNPV) infection. Our data indicate that IBM1 function might be reduced by viral anti-apoptotic genes when BmN cells are infected by BmNPV.