Photoactivatable Cre Knock-In Mice for Spatiotemporal Control of Genetic Engineering 
<i>in vivo</i>

Although the Cre-loxP recombination system has been extensively used to analyze gene function in vivo, spatiotemporal control of Cre activity is a critical limitation for easy and precise recombination. Here, we established photoactivatable-Cre (PA-Cre) knock-in mice at safe harbor locus for the spatial and temporal regulation of Cre recombinase activity. The mice showed Cre recombination activity in a whole-body following light exposure for only 1 h. Almost no leaks of Cre recombination activity were detected in the knock-in mouse under natural light conditions. Spot irradiation could induce locus-specific recombination noninvasively, enabling us to compare phenotypes on the left and right sides in the same mouse. Furthermore, long-term irradiation using an implanted wireless LED substantially improved Cre recombination activity, especially in the brain. These results demonstrated that the PA-Cre knock-in mice can facilitate spatiotemporal control of genetic engineering and promise a useful resource to elucidate gene function
in vivo with Cre-loxP.

Keywords: Photoactivatable, Cre, loxP, knock-in, mouse, CRISPR, wireless LED, spatiotemporal control

Suggested Citation: Suggested Citation

Yoshimi, Kazuto and Yamauchi, Yuko and Tanaka, Takao and Shimada, Toshio and Sato, Moritoshi and Mashimo, Tomoji, Photoactivatable Cre Knock-In Mice for Spatiotemporal Control of Genetic Engineering in vivo. Available at SSRN: https://ssrn.com/abstract=3564992 or http://dx.doi.org/10.2139/ssrn.3564992

This version of the paper has not been formally peer reviewed.