Baculovirus-Mediated Efficient Gene Transfer into the Central Nervous System of the Silkworm, Bombyx mori

抄録

We have successfully developed an efficient gene transfer system using the recombinant baculovirus (AcNPV) in the silkworm, Bombyx mori. A driver-reporter cassette with an EGFP reporter was inserted into AcNPV bacmid using the Bac-to-bac baculovirus expression system. The gene transfer was accomplished by injection of the recombinant AcNPV into larvae or pupae. A cassette driven by the Bombyx actin A3 promoter clearly gave EGFP fluorescence in the whole body, including the central nervous system (CNS). To apply this system for analysis of neurohormone gene expression mechanisms, cassettes were constructed with the promoters of three insect neuropeptide hormone genes: bombyxin, a prothoracicotropic hormone (PTTH), and diapause hormone-pheromone biosynthesis activating neuropeptide (DH-PBAN). The bombyxin promoter directed the EGFP expression to the median 8 neurosecretory cells of the brain, PTTH to the lateral 4 neurosecretory cells of the brain and DH-PBAN to 14 cells of the suboesophageal ganglion, which have been identified to be the neuropeptide hormone-producing cells. This assay is time saving, convenient, and highly reproducible, so that the present system provides a new tool for analysis of the neuropeptide hormone gene expression in the CNS.