Evidence for Transgenerational Immunity in Antiviral Immunity in Silkworm, Bombyx mori

Transgenerational immune priming (TGIP) is a phenomenon in which parental exposure to pathogen infection enhances resistance to pathogens in their offspring. TGIP has been reported in several insects, including Lepidoptera, but it has not yet been documented in silkworms. In this study, we demonstrated the existence of TGIP in silkworms by exposing the parental generation to a low dose of Bombyx mori nucleopolyhedrovirus (BmNPV). Notably, when maternal or paternal-primed moths were mated to produce the F1 generation, the F1 generation larvae from both primed groups were more resistant to the BmNPV challenge than silkworm larvae with only maternal or paternal priming. Importantly, both maternal and paternal contributions to offspring immunity were essential for TGIP. However, due to the characteristics of the BmNPV itself, no within-generation immune responses were detected following BmNPV priming. Further analysis revealed that immune-related genes might play a role in mediating specific TGIP in silkworms after BmNPV priming. These results broaden our understanding of TGIP and the antiviral memory of insects in their offspring.