GENETICALLY MODIFIED EUKARYOTIC CELLS

摘要

The invention relates to a method of producing genetically modified eukaryotic cells with optimised growth characteristics wherein a recombinant first nucleotide sequence has been integrated into a desired position in the genome. The sequence contains at least one gene encoding a plasma membrane protein with either toxin-receptor or toxic properties and allowing for surface expression based cell sorting to identify a suitable genomic integration locus. The invention also relates to a second exogenous nucleotide sequence containing at least one protein of interest as well as a vector, which aids in the site specific exchange of the first with the second nucleotide sequence. Efficient exchange is achieved by a stringent selection strategy that will kill all cells still expressing the plasma membrane protein.