Construction And Study Of Gene-targeting Vectors Expressing HGM-CSF In Silkworm Silk Gland Bioplant

The silk gland of silkworm (Bombyx mori) is a potential bio-plant.For implementing the specific expression of exogenous gene in slik glandular tissue by gene targeting,Two fragments of Fibroin Heavy Chain Protein Gene (fib-H)was cloned and sequensed,One contains the promoter and its double-ended flanking fragment (DQ989298).Another contains the 1st intron and the 2nd exon partial sequence(EU346954).the results shows that the two fragments have the identity of 98.84% and 99.58% respectively with the public sequence (GenBank accession No:AF226688);The secondary structure analysis indicates that the region of the promoter could shape to loop-stem structure which may related to the recognization and action of modulin.;The analyzed of the partial amino acid sequence encoded by the 2nd exon with more insects fibroin protein shows that different fibroin protein have potential conservation motif of GX3EX3TX1KX20-22X1VX3DX2GX1EX3EEDV,the sequence may take important part in the structure of fibroin protein. The two fragments of fibrion protein heavy chain was used as two homologous arm, succeeded to construct the gene targeting vector that contained GFP gene drived by A3 promoter and hGM-CSF drived by the promoter of fibrion light chain. The result of translation in vitro and transient expression in vivo shows that the vector of gene targeting can express hGM-CSF, GFP also can be tested in posterior silk gland. Relevant result settled foundation for expression of gene targeting in glandular tissue.