Abstract: Strategies, systems, compositions, and methods for efficient production of knock-in cellular clones without reporter genes. An essential gene is targeted using a knock-in cassette that comprises an exogenous coding sequence for a gene product of interest (or “cargo sequence”) in frame with and downstream (3?) of an exogenous coding sequence or partial coding sequence of the essential gene. Undesired targeting events create a non-functional version of the essential gene, in essence a knock-out, which is “rescued” by correct integration of the knock-in cassette, which restores the essential gene coding region so that a functional gene product is produced and positions the cargo sequence in frame with and downstream of the essential gene coding sequence.

Abstract: The present disclosure provides molecular tools, methods and kits for using cell division loci (CDLs) to control cell proliferation in animal cells. CDLs, as provided herein, are loci whose transcription product(s) are expressed during cell division. CDLs may be genetically modified, as described herein, to comprise a negative selectable marker and/or an inducible activator-based gene expression system, which allows a user to permit, ablate, and/or inhibit proliferation of the genetically modified cell(s) by adding or removing an appropriate inducer.

Abstract: The present disclosure provides molecular tools, methods and kits for using cell division loci (CDLs) to control cell proliferation in animal cells. CDLs, as provided herein, are loci whose transcription product(s) are expressed during cell division. CDLs may be genetically modified, as described herein, to comprise a negative selectable marker and/or an inducible activator-based gene expression system, which allows a user to permit, ablate, and/or inhibit proliferation of the genetically modified cell(s) by adding or removing an appropriate inducer.