Production of biofilaments in transgenic animals
Disclosed is a method for the recombinant production of biofilaments, such as spider silk or insect fibroins, using transgenic animals which secrete the biofilaments in their milk and/or urine, and transgenic cells which secrete the biofilaments into culture media. Such a method is useful for producing large quantities of biofilament material. Also disclosed is a nucleic acid molecule for generating such transgenic animals.
1. A transgenic female ruminant comprising germline and somatic cells that comprise a nucleic acid molecule comprising a mouse whey acidic protein (WAP) promoter operably linked to a nucleotide seciuence encoding a polypeptide, wherein the polypeptide comprises a biofilament polypeptide and a leader sequence that enables secretion of the biofilament polypeptide by milk-producing cells into milk of the ruminant, wherein the biofilament polypeptide is a dragline silk polypeptide selected from the group consisting of Araneus diadematus fibroin-3 (“ADF-3”), Araneus diadematus fibroin-4 (“ADF-4”), Neyhila clavipes dragline silk-1 (“NcDS-1”), and Nephila clavipes dragline silk-2 (“NcDS-2”), and wherein the ruminant secretes the biofilament polypeptide into milk.
2. A method for producing a biofilament polypeptide, comprising: providing a transgenic female ruminant of claim 1 and isolating the biofilament polypeptide from milk produced by the transgenic female ruminant.
3. The transgenic female ruminant of claim 1 , wherein the biofilament polypeptide is ADF-3.
4. The transgenic female ruminant of claim 1 , wherein the biofilament polypeptide is ADF-4.
5. The transgenic female ruminant of claim 1 , wherein the biofilament polypeptide is NcDS-1.
6. The transgenic female ruminant of claim 1 , wherein the biofilament polypeptide is NcDS-2.