Patent ID: 6872869

Claim:
A method for establishing an expression system of spider dragline silk gene in Bombyx mori , comprising the steps of: (1) ligating a cDNA encoding spider dragline silk protein or a cDNA encoding the repetitive amino acid sequence part of a spider dragline silk protein with a cDNA comprising the nucleotide sequence of SEQ ID NO:1 encoding the silkworm fibroin L chain, placing the ligated DNA under the control of the promoter of a L chain gene and terminating the ligated DNA with the terminator of the L chain gene, thereby obtaining a fused gene; (2) ligating the fused gene with a reporter gene to obtain a ligated product, inserting the ligated product thus obtained between the two inverted terminal repeats of the transposon of piggyBac, thereby obtaining a recombinant transposon; (3) constructing a transposase gene expression vector by using a transposase gene; (4) co-transforming a silkworm egg by using the recombinant transposon obtained in step ( 2 ) and the transposase gene expression vector obtained in step ( 3 ) to obtain a transformed silkworm egg; (5) obtaining a transgenic silkworm which expresses a spider dragline/L chain fibroin silk fusion protein by cultivating and screening the larva of a plurality of the transformed egg of step (4) for expression of the spider dragline/L chain fibroin silk fusion protein.