Comparison of anti-viral activities of the silkworm larvae reared in light and in darkness in relation to the formation of red fluorescent protein (RFP)

According to our previous in vitro experiments, light was indispensable to the formation of RFP, which is present in the digestive juice of silkworm larvae. In this report, the influence of light on the RFP levels in the living larvae has been examined by rearing them under either light or dark condition, and comparing the RFP contents in their digestive juice. The RFP was not produced in darkness. In accordance to the fact that the RFP has the anti-viral activity, the larvae reared in light was found to be less susceptible against the orally administered NPV virus than those reared in darkness.