Bombyx

Biology

Gene

Genome editing

Fibroin

Genome

Composite material

Ecology

Materials science

Spider silk

SILK

Bombyx mori

Transcription activator-like effector nuclease

Spider

Genetics

Proceedings of the National Academy of Sciences

Significance The use of heterologous systems to express spider silk has become an attractive method. However, achieving cost-effective production and high yields is still challenging. Here, we describe the establishment of a targeted gene replacement system in Bombyx mori to express the major ampullate spidroin-1 gene ( MaSp1 ) from the spider Nephila clavipes . With the aid of transcription activator-like effector nuclease-mediated homology-directed repair, we genetically replaced the silkworm fibroin heavy chain gene with MaSp1 with considerable transformation efficiency, and the chimeric MaSp1 yields reached up to 35.2% wt/wt of cocoon shells in transformed silkworms. The genetically modified silk fiber had significant changes in mechanical properties, with improved extensibility. This system will shed light on the future mass production of new biomaterials, including spider silk.

Mass spider silk production through targeted gene replacement in <i>Bombyx mori</i>

Mass spider silk production through targeted gene replacement in Bombyx mori