114 results about "Silk gland" patented technology

The invention relates to a silkworm fibroin heavy-chain gene mutation method, which specifically comprises the step of: acting mRNA (Messenger Ribonucleic Acid) of a coded zinc-finger nuclease sequence on loci 1325-1362 of a silkworm fibroin heavy-chain gene shown as SEQ ID NO:1 to form target positions for recognizing zinc-finger nuclease, thereby obtaining a series of silkworm fibroin heavy-chain mutated genes; and the mutated sequence can be applied to preparation of sericin and extrinsic proteins. Mutants provided by the invention have the following advantages that: (1) a posterior division of silkgland of a fibroin heavy-chain gene mutant provided by the invention serious degrades, a cocoon shell only contains the sericin synthesized and secreted by a middle division of silkgland, if the mutated strains are utilized to transgenically express the extrinsic proteins, the expressed amount and the purity of the extrinsic proteins can be greatly increased, and thus, a brand-new useful genetic material is provided for the development of a silkworm fibroin bioreactor; and (2) the cocoon shell of the mutated strain provided by the invention only contains the sericin, and thus, a new source is provided for the large-scale production of the sericin.

The invention discloses a method for building a domestic silkworm silk gland biologic plant. A recombinant transgene vector which is provided with domestic silkworm silk protein specificity promoter controlled extraneous gene expression cassettes, an enhancer activity component, antibiotic resistant genes and fluorescent protein reporter genes and based on a piggyBAC transposon is established through gene engineering operations. The transgene vector is introduced into primarily laid eggs, special antibiotics are fed to hatched newly exuviated silkworms continuously until the fourth instar. In this way, silkworms which can resist the specific antibiotics and are provided with fluorescent protein reporter genes are obtained; target genes are detected; and transgene silkworms are manufactured by breeding. By adopting the silk gland tissues of the transgene silkworms, protein drugs can be obtained. With the method disclosed by the invention, transgene domestic silkworm silk gland plants can prepare protein drugs at low manufacture cost without potentially hazardous rhabdovirus. The method is safe and is practically valuable.

The invention discloses a method for synthesizing and secreting black widow spider dragline silk protein 1 through a bombyx mori silk gland bioreactor. The method includes the steps that firstly, pBac[3xP3-DsRed]-MaSp1 plasmids serving as a carrier for bombyx mori to synthesize and secrete black widow spider dragline silk protein 1 are established; then, plasmids and assistant plasmids are introduced into bombyx mori zygotes through microinjection, red fluorescence protein genes and black widow spider dragline silk protein 1 genes are introduced into bombyx mori genomes through the transposition characteristic of piggyBac transposons, stable inheritance and expression are performed, transgenic bombyx mori is obtained, mori moth selfing is performed to achieve homozygosis of black widow spider dragline silk protein 1 genes, and transgenic bombyx mori secreting black widow spider dragline silk protein 1 is bred. According to the method, transgenic bombyx mori is screened through fluorescence marker genes, and black widow spider dragline silk protein 1 is specifically synthesized and secreted through bombyx mori silk gland cells; the method is used for development and utilization of spider silk and can also be used for improving the mechanical performance of silk.

The invention relates to a transgenic method for improving silk yield. Genes promoting cell growth are specifically expressed in posterior silk glands of silkworms, silkworms with enlarged posterior silk glands are obtained, and the yield of silk is high. The invention provides genes promoting the growth of posterior silk glands and an expression system suitable for expressing the genes promotingthe growth of posterior silk glands at high specificity in the posterior silk glands of the silkworms. The invention provides novel means and a method for improving silk producing characters of the silkworm variety.

As novel means for causing any recombinant protein produced by the silkworm middle silk gland to be secreted in cocoons and easily extracting the recombinant protein from the cocoons without modification of the conformation of the protein, there is provided a polynucleotide that in an expression cassette for expression of a recombinant protein by the silkworm middle silk gland, is functionally linked to a recombinant protein structure gene, which polynucleotide is one composed of a polynucleotide constructing the promoter regions of sericin 1 or sericin 2 gene and, functionally linked thereto, a polynucleotide constructing the homologous regions of baculovirus.

The present invention provides a genetic engineering material for insects that enables a target protein to be purified easily, without requiring the use of recombinant baculovirus, while simultaneously providing a process for producing exogenous protein using that genetic engineering material. A gene recombinant silkworm is obtained by inserting an exogenous protein gene such as a cytokine gene coupled to a promoter that functions in silk glands into a silkworm chromosome. An exogenous protein such as a cytokine is then extracted and purified from the silk glands or cocoon of that silkworm or its offspring. A large amount of exogenous protein can be produced within silk gland cells, outside silk gland cells or in silk thread or a cocoon by inserting an expression gene cassette, in which the DNA sequence of the 3′ terminal portion and the DNA sequence of the 5′ terminal portion of fibroin H chain gene are fused to the exogenous protein gene, into silk gland cells and so forth.

Transgenic silkworms comprising GFP whose expression is regulated by the sericin gene promoter were produced. Observation of the silk glands of the last instar larvae of the silkworms showed fluorescence only in the middle silk glands. GFP was secreted from middle silkgland cells from around the spinning stage, indicating that GFP moved into the gland lumen. Finally, GFP was spun into cocoon filaments, and cocoons containing large amounts of GFP were produced. Thus, by using the promoter region of the sericin gene, recombinant proteins can be produced in the middle silk glands. Furthermore, the recombinant proteins produced in the middle silk glands were readily secreted into the lumen of the middle silk glands.

A transformed silkworm which has a polynucleotide encoding human collagen in its genomic DNA and produces recombinant human collagen as a part of proteins in its cocoon or silk gland; a process for producing human collagen by using this transformed silkworm; and a recombinant vector to be used in the constitution of the transformed silkworm. Since human collagen is collected from the cocoon discharged by this transformed silkworm or its silk gland, highly pure human collagen can be conveniently obtained in a large amount. Moreover, the recombinant human collagen produced by the transformed silkworm is a highly safe collagen which is free from any fear of the contamination with pathogens such as viruses or prions and shows no antigenicity on humans. Thus, it is usable in various industrial fields including medicines, foods and cosmetics.