PROBLEM TO BE SOLVED: To provide a method for producing recombinant proteins in the silkworm middle silk gland. SOLUTION: Transgenic silkworms having GFP whose expression is controlled by a sericin gene promotor are produced. Observation of the silk glands of the larva in the last instar of the silkworm shows fluorescence only in the middle silk glands. It is also found that GFP is secreted from the middle silk gland cells from around the spinning stage, and that GFP is moved into the gland lumen. Finally, GFP is spun into cocoon filaments, and a cocoon containing a large amount of GFP is produced. In this way, it is discovered that recombined proteins can be produced in the middle silk glands by utilizing the promotor region of the sericin gene, and also discovered that the recombinant proteins produced in the middle silk gland can be easily secreted into the inner lumen of the middle silk glands. COPYRIGHT: (C)2013,JPO&INPIT
