Single-cell in vivo imaging of cellular circadian oscillators in zebrafish

摘要: The circadian clock is a cell-autonomous time-keeping mechanism established gradually during embryonic development. Here, we generated transgenic zebrafish line carrying destabilized fluorescent protein driven by the promoter of core gene, nr1d1, to report in vivo rhythm at single-cell level. By time-lapse imaging this fish and 3D reconstruction, observed sequential initiation reporter expression starting photoreceptors pineal gland, then spreading cells other brain regions Even within found heterogeneous onset nr1d1 expression, which each cell undergoes oscillation superimposed over type-specific developmental trajectory. Furthermore, that showed synchronous under light-dark (LD) cycle. Remarkably, oscillations were dramatically dampened rather than desynchronized animals raised constant darkness, while trend still persists. It suggests light exposure early embryos has significant effect on cellular oscillations.