An efficient method for multigene co-interference by recombinant Bombyx mori nucleopolyhedrovirus.

Area of Science:

• Virology
• Insect Pathology
• Molecular Biology

Background:

• Bombyx mori Nucleopolyhedrovirus (BmNPV) causes significant lethal infections in silkworms, leading to substantial economic losses in the silk industry.
• Understanding BmNPV replication and identifying essential viral genes is crucial for developing effective control strategies.

Purpose of the Study:

• To investigate the impact of different gene inhibition strategies on BmNPV replication.
• To compare the efficacy of single-gene versus multigene interference strategies against BmNPV.

Main Methods:

• Construction of recombinant BmNPV with single or multigene-interfering cassettes targeting essential viral genes (ie0, ie1, gp64).
• Infection of BmN cells and silkworms with engineered viruses.
• Assessment of gene expression, virus titer, progeny virion production, and silkworm mortality.

Main Results:

• Inhibition of the ie1 gene (dsie1) demonstrated superior efficacy in reducing target gene expression, virus titer, and silkworm mortality compared to dsie0 and dsgp64.
• The ie1 gene plays a critical role in BmNPV replication, as evidenced by reduced progeny virions and lower lethality with dsie1 interference.
• Multigene co-interference strategies significantly outperformed single-gene interference in inhibiting virus titer and reducing silkworm mortality (p < 0.05).

Conclusions:

• The ie1 gene is a key target for BmNPV inhibition.
• Multigene interference strategies provide enhanced and continuous interference against BmNPV.
• This approach offers a novel platform for breeding disease-resistant silkworms with improved traits.