Daiichi Seiyaku Co., Ltd.

Japan Science and Technology Corporation

Research Development Corporation of Japan

Mitsuru Furusawa

Susumu Maeda

Fumio Imamoto

Yoshiyuki Saeki

Yoshizumi Ishino

Yoshinari Sato

Tadashi Horiuchi

Kiyoshi Tanabe

Yasumasa Marumoto

Hirofumi Doi

This application provides a method for mutagenesis of a gene, which comprises introducing much more point mutations into one strand of double-stranded genomic DNA of cell or organism individual than into another strand. In accordance with such a method, it is now possible to efficiently and effectively construct various useful mutants of microorganisms, cells or organism individuals. It is also now possible by analyzing the mutating conditions of the gene to clarify the mechanism of drug resistance, to estimate the occurrence of a novel insensible microorganism or to develop a drug therefor, to analyze the mutation of an oncogene and the mechanisms of cancer metastasis and increase in malignancy, to develop a therapeutic method using these mechanisms, etc.

Mutagenesis method

This invention provides A method for preparing mutant genes, which comprises the steps of constructing a recombinant plasmid DNA by inserting a gene fragment into a plasmid DNA having a unidirectional origin, introducing the recombinant plasmid DNA into host cell lacking DNA error-correcting function to transform the host cell, and culturing the transformant cell in a condition that any mutations of the inserted gene is detectable. According to the present invention, diverse mutant genes can be prepared in a short period of time.

Method for preparing mutant genes

A method of producing useful substances which comprising propagating in cultured cells or in a host a recombinant Bombyx mori nuclear polydegrosis virus (BmNPV) DNA is disclosed. The BmNPV DNA is produced by recombination with a double-stranded DNA containing (i) a 5'-upstream BmNPV DNA fragment orginally occurring upstream from the structural gene coding for the production of polyhedral protein and also including the promoter region for the structural gene, (ii) a translational start codon and (iii) a gene coding for the production of a useful substance exogenous to the virus, with or without (iv) a 3'-downstream BmNPV DNA fragment originally occurring downstream from the structural gene coding for the production of polyhedral protein.

Method of producing substances in living silkworms

Recombinant Bombyx mori nuclear polyhedrosis viruses having, in the polyhedral protein-encoding structural gene portion of the Bombyx mori nuclear polyhedrosis virus DNA (BmNPV DNA), a structural gene for a desired protein as joined to the whole of or a part of the polyhedral protein-encoding structural gene with or without interposition of a linker base sequence are provided. By propagating the above viruses in silkworm-derived cells or silkworms, fused proteins of a desired protein and the whole of or a part of the polyhedral protein as joined together with or without interposition of a linking amino acid or peptide are produced. The desired proteins can be obtained from the fused proteins by cleavage or decomposition at the linking site.

Method of producing peptides using baculovirus vectors in cultured cells

Growing community of inventors

Tokyo, Japan

Mitsuru Furusawa