A Highly Efficient and Simple Construction Strategy for Producing Recombinant Baculovirus <i>Bombyx mori</i> Nucleopolyhedrovirus

<div><p>The silkworm baculovirus expression system is widely used to produce recombinant proteins. Several strategies for constructing recombinant viruses that contain foreign genes have been reported. Here, we developed a novel defective-rescue <i>Bm</i>NPV Bacmid (reBmBac) expression system. A <i>CopyControl</i> origin of replication was introduced into the viral genome to facilitate its genetic manipulation in <i>Escherichia coli</i> and to ensure the preparation of large amounts of high quality reBmBac DNA as well as high quality recombinant baculoviruses. The <i>ORF1629</i>, <i>cathepsin</i> and <i>chitinase</i> genes were partially deleted or rendered defective to improve the efficiency of recombinant baculovirus generation and the expression of foreign genes. The system was validated by the successful expression of <i>luciferase</i> reporter gene and porcine <i>interferon γ</i>. This system can be used to produce batches of recombinant baculoviruses and target proteins rapidly and efficiently in silkworms.</p>