Kinetics of the light inducible transcription system driven by <i>elav</i>^<i>c155</i>-Gal4 with LexAOP2-Gal80 feedback control.

<p>(A) Effect of light intensity on GFP expression levels in embryos and adults. The average GFP intensity of the nervous system was measured in embryos after 4 hours of blue light illumination (n>10, mean±s.d.). The total GFP intensity of the whole brain was measured in the adults because of an uneven GFP distribution among the various brain regions. Adult flies were illuminated with continuous blue light for ~16 hours (n>5, mean±s.d.). (B) Effect of exposure time on GFP expression levels in embryos and adults. The GFP expression levels in the nervous system were measured after illuminating embryos or adults with blue light (474nm, ~2.5mWcm^-2) for the specified periods of time (n>7, mean±s.d.). (C) Selective spatial induction of gene expression using two-photon excitation. The region of interest is highlighted with the red line (left image) and exposed to two photon excitation (860nm, 80MHz, 200fs pulse width) for 4 hours. The Z-stack projection of the GFP expression pattern in the nervous system was imaged immediately afterwards (right image). A 3D-reconstruction of the exposed region is shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0138181#pone.0138181.s006" target="_blank">S1 Movie</a> (Scale bar = 100μm).