PT  - JOURNAL ARTICLE
AU  - Yuping Huang
AU  - Caitlin McCann
AU  - Andrey Samsonov
AU  - Dmitry Malkov
AU  - Gregory D Davis
AU  - Qingzhou Ji
TI  - Modulation of Genome Editing Outcomes by Cell Cycle Control of Cas9 Expression
AID  - 10.1101/127068
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 127068
4099  - http://biorxiv.org/content/early/2017/04/12/127068.short
4100  - http://biorxiv.org/content/early/2017/04/12/127068.full
AB  - Targeting specific chromosomal sequences for genome modification or regulation during particular phases of the cell cycle may prove useful in creating more precise, predictable genetic changes. Here, we present a system using a fusion protein comprised of a programmable DNA modification protein, Cas9, linked to a cell cycle regulated protein, geminin, as well as green fluorescent protein (GFP) for visualization. Despite the large size of Cas9 relative to geminin, cells were observed to express Cas9-GFP-geminin at levels which oscillate with the cell cycle. These fusion proteins are also shown to retain double-strand break (DSB) activity at specific chromosomal sequences to produce both indels and targeted integration of donor ssDNA. Most importantly, the ratio of ssDNA donor integration to non-homologous end joining (NHEJ) was observed to increase, suggesting that cell cycle control Cas9 expression may be an effective strategy to bias DNA repair outcomes.