Fig. 6

Blue light induces neuroprotective gene expression changes in photoreceptors via calcium-dependent and independent pathways. a Newly-eclosed (day one) flies express high levels of genes that enable them to withstand blue light exposure. Exposure to standard white light conditions during the first week of life increases oxidative stress levels in photoreceptors, correlating with increased expression of some stress response genes. Concomitantly, post-development transitions in gene expression between newly-eclosed and mature flies result in reduced levels of genes required to maintain redox homeostasis and buffer calcium. Following exposure to acute blue light, mature six-day-old flies activate a strong neuroprotective gene expression program in an effort to prevent retinal degeneration. b Blue light-induced changes in gene expression in six-day-old flies include calcium-dependent upregulation of stress response genes, and calcium-independent downregulation of genes involved in light response such as calcium and ion channels. This gene expression program enables six-day-old flies to resist moderate (3 h) blue light exposure, but is not sufficient to prevent retinal degeneration when flies are subjected to longer periods of blue light (8 h)