<i>In Vivo</i> Injection of Reversible Optically Controlled Short Interfering RNA into Japanese Medaka Embryos (<i>Oryzias latipes</i>) to Regulate Gene Silencing

Photoswitchable <i>ortho</i>-functionalized tetrafluorinated azobenzene-modified siRNAs (F-azo-siRNAs) were synthesized using solid-phase phosphoramidite chemistry. The activity of an F-azo-siRNA targeting enhanced green fluorescence protein (eGFP) in transgenic (Tg) Japanese Medaka (<i>Oryzias latipes</i>) was reversibly photocontrolled with blue (470 nm) and green (530 nm) light, to activate and inactivate the siRNA, respectively. This study highlights the first reversible <i>in vivo</i> study with photoswitchable siRNA. Controlling siRNA function reversibly <i>in vivo</i> could open new opportunities for biotech research to better understand gene function and cellular mechanisms.