Kyoto, Japan, December 11, 2001--- The Biomedical Group of Takara Shuzo Co., Ltd. announced today that its scientists had developed a new method which can integrate a foreign gene efficiently into a target genome of any species. They believe the method, named recombinant Pre-Integration Complex (rPIC) method, is superior to the retrovirus vector method frequently used for gene therapy in ability. The rPIC method can be used for generation transgenic animals as well as gene therapy approaches.

In retroviral vector systems, recombinant viruses infect target cells and their genes are entered into the cytoplasm of the cells, in which they form rPICs with proteins such as integrase immediately before integrating into chromosomal DNA. In the newly developed rPIC method, rPICs are extracted from the cytoplasm of cells infected by recombinant retrovirus and transferred into another target cells by physical or chemical procedure such as microinjection (Fig. 1). The rPIC contains all components necessary for its integration process into chromosome. Therefore, a foreign gene carried by rPIC is integrated rapidly and reliably into the host chromosomal DNA.

The scientists found that rPIC prepared from ecotropic retrovirus could integrate a foreign gene into host chromosomal DNA in a human cell line and fertilized egg of medakafish at nearly 100% efficiency. The results show the possibility that rPIC method can be used to efficiently introduce a foreign gene into a target genome independent of species.

The Group has plans to develop reagents for gene transduction by using rPIC method in the fields of gene therapy and generation of transgenic animals

This article is translated from press release in Japanese for your convenience.