Patent ID: 9131671
Filing Date: 2015-09-15
Classification: A01K,C07K,C12N

Abstract:
1. A method of making a silkworm that produces a silk comprising a spider silk polypeptide, or an analog of a spider silk polypeptide, in place of a native silk fibroin polypeptide; comprising the steps of: a) providing a silkworm; b) transforming the silkworm of step (a) by ligating a DNA sequence encoding a spider silk fibroin polypeptide, or an analog of a spider silk fibroin polypeptide, between a portion of the 5′ and 3′ ends of a native silkworm fibroin gene to replace, by homologous recombination, a sequence encoding native silkworm fibroin alpha helix and beta-sheet domains with the DNA sequence encoding the spider silk fibroin polypeptide or the analog of the spider silk fibroin polypeptide, wherein the analog of the spider silk fibroin polypeptide is encoded by at least 2800 nucleotides encoding alternating beta-sheet domains and alpha helix domains, and wherein the amino acid sequence of the beta-sheet domains of the analog of the spider silk fibroin polypeptide are each at least 60% identical to at least one of the beta-sheet domains as set forth in SEQ ID NO: 2, and c) obtaining a transgenic silkworm from step (b) that produces a silk that is at least 50% stronger than native silkworm silk.