Production of Transgenic Silkworms Resistant to BmNPV

由核型多角体病毒(BmNPV)感染引起的核型多角体病是世界各国养殖业面临的主要问题。在感染NPV的细胞中抑制这些必需基因的功能表达是预防家蚕BmNPV致死性感染的有效策略。杆状病毒的即刻早期基因产物IE1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S的拮抗型IE1(IE1TN)，并证明表达IE1TN的BmN细胞的病毒产量显著降低。另一方面，最近的研究表明，dsRNA是植物和动物基因特异性沉默的强大工具。然后，我们构建了含有IEF-1和dNAHEL等基本病毒基因序列的重组表达dsRNAs的重组载体，并证明了在表达dsRNAs的BmN细胞中病毒的产生被有效地抑制。最后，利用转座子背负系统，我们证实了转IE1TN或dsRNA表达基因的家蚕对BmNPV的中等抗性。

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.