Abstract: An object of the present invention is to provide a method for producing a reversibly immortalized cell which can allow a cell into which an immortalizing gene is introduced to proliferate over a long period without damaging the chromosome of the cell, and is capable of removing the immortalizing gene, and to provide a method for obtaining a large amount of a reversibly immortalized cell that can be cloned and has stable quality. The present invention provides a method for producing a reversibly immortalized cell, comprising the steps of: introducing a chromosomally non-integrated RNA virus vector loaded with one or two or more immortalizing gene(s), selected from the group consisting of Bmi-1 gene, TERT gene, and SV40T gene, into a mammalian cell so that the immortalizing gene is expressed in the cell; and culturing the obtained cell for proliferation.

Abstract: This application provides a method for preparing human cell-derived microcells from human cells comprising DNA of interest, comprising: a step of culturing human cells in a medium containing at least one micronucleus inducer selected from the group consisting of microtubule polymerization inhibitors (excepting colcemid), microtubule depolymerization inhibitors, and spindle checkpoint inhibitors, thereby to produce human cell-derived microcells; and a step of collecting human cell-derived microcells comprising the DNA of interest, and a method for preparing human cells comprising DNA of interest by use of the method, which can be also applied to non-human animal cells.

Abstract: The present application provides: a method for producing human induced pluripotent stem (iPS) cells comprising an exogenous chromosome having a DNA of interest using the MMCT method; and a method for expressing the exogenous gene in the human iPS cells prepared by the method for producing human iPS cells, or in undifferentiated or differentiated cells derived from the human iPS cells induced to differentiate from the human iPS cells.

Abstract: This application provides: a nucleic acid construct characterized by comprising, in a mammalian artificial chromosome vector, a DNA sequence of interest, a matrix attachment region, and a replication origin, and by using for high expression of the DNA; a mammalian cell comprising the nucleic acid construct; and a method for high production of a protein encoded by the DNA of interest in the mammalian cell.