Production of Transgenic Silkworms Resistant to BmNPV

由家蚕核型多角体病毒（BmNPV）感染引起的核型多角体病是世界水产养殖业的主要问题。抑制BmNPV感染细胞中这些必需基因的功能性表达是预防BmNPV致死性感染的有效策略。杆状病毒的立即早期基因产物IE 1是病毒基因表达和病毒DNA复制所必需的。我们构建了家蚕核型多角体病毒（BmNPV）的拮抗性IE 1（IE 1 TN），并证明在表达IE 1 TN的BmN细胞中病毒产量显著降低。另一方面，最近的研究表明，dsRNA是植物和动物中基因特异性沉默的有力工具。然后，我们构建了设计用于表达具有必需病毒基因（如Ief-1和dnahel）的序列的dsRNA的重组质粒，并证明在表达dsRNA的BmN细胞中病毒产生被有效抑制。最后，利用转座子搭载系统，我们证实了在转基因家蚕中IE 1 TN或dsRNA表达基因的转基因引起的BmNPV的中度抗性。

The nuclear polyhedorosis disease caused by BmNPV infection is a major problem in suriculture around the world. The inhibition of the functional expression of these essential genes in cells infected with NPV should be an effective strategy for preventing mortal infections of BmNPV in the silkworm.An immediate-early gene product of baculovirus, IE1, is essential for viral gene expression and for viral DNA replication. We constructed an antagonistic IE1 (IE1TN) of Bombyx mori nuclear polyhedrosis virus (BmNPV)s and demonstrated markedly reduced virus production in BmN cells expressing IE1TN. On the other hand, recent study demonstrated that dsRNA is a powerful tool for gene-specific silencing in plants and animals. Then, we constructed recombinant plasmids designed for expressing dsRNAs with the sequences of the essential viral gene, such as Ief-1 and dnahel and demonstrated that viral production was effectively inhibited in BmN cells expressing dsRNAs. Finally, using a transposon piggyback system, we confirmed the moderate BmNPV-resistance caused by the transgenesis of the IE1TN-or dsRNA-expressing gene in the transgenic silkworms.