Phase II Trials of Transgenic Silkworms Resistant to Bombyx mori Nuclear Polyhedrosis Virus (BmNPV) Resume in India
Key Insights
Field trials for transgenic silkworms, engineered for resistance to Bombyx mori nuclear polyhedrosis virus (search) (BmNPV (search)), have resumed in Andhra Pradesh and Karnataka.
The trials aim to assess the efficacy of the transgenic silkworms across different agro-climatic zones, potentially enabling year-round silkworm rearing.
Researchers used piggyBac-mediated germline transgenesis to transfer the virus resistance gene into the silkworm genome, enhancing resilience to BmNPV (search) infections.
Field trials for transgenic silkworms engineered to resist the Bombyx mori nuclear polyhedrosis virus (search) (BmNPV (search)) have recommenced in Andhra Pradesh and Karnataka. These Phase II multi-locational trials, approved by the Genetic Engineering Appraisal Committee (GEAC) of the Ministry of Environment, focus on evaluating the efficacy of these silkworms across diverse agro-climatic conditions. The goal is to mitigate silkworm mortality caused by viral infections and enable year-round silkworm rearing by farmers. This initiative addresses significant economic losses in the Indian sericulture industry due to BmNPV.
Development and Methodology
The transgenic silkworms were developed through a collaborative effort between the Centre for DNA Fingerprinting and Diagnostics (search) (CDFD) and the AP State Sericulture Research and Development Institute (search) (APSSRDI). Researchers at APSSRDI employed piggyBac-mediated germline transgenesis to introduce a virus resistance gene into the silkworm genome. The virus-resistant trait, initially developed in the Nistari genetic background, was successfully transferred to the CSR2 silkworm strain through a marker-assisted repeated backcross strategy. This ensures the desirable traits of the CSR2 strain are maintained while incorporating the BmNPV (search) resistance.
Trial Objectives and Oversight
The second phase of trials builds upon initial studies conducted between 2015 and 2017. GEAC has mandated comprehensive feed safety, efficacy, and overall safety studies to ensure the trials remain contained and pose no environmental or health risks. These studies are crucial to validate the benefits of the transgenic silkworms while adhering to stringent regulatory standards.
Impact and Challenges in Sericulture
Indian sericulture faces persistent challenges, particularly in bivoltine silk production throughout the year. Farmers often rely on cross-bred hybrids during adverse conditions, which are susceptible to BmNPV (search) infections, leading to substantial crop losses. Experts suggest that the risk of allergenicity from transgenic silk is negligible. The introduction of BmNPV-resistant silkworms could significantly reduce these losses and improve the sustainability of silk production.