The time of the circadian time points in the mouse brain scRNAseq dataset


First of all, thank you for providing this wonder resources and including light/dark time points for us to study the circadian changes of gene expression in the brain.

I’d like to have a little bit more details on the time when the brains were collected.

In the paper:
A high-resolution transcriptomic and spatial atlas of cell types in the whole mouse brain

Method part:
“Mice were provided food and water ad libitum and were maintained on a regular 14:10 h light:dark cycle, or on a reversed 12:12 h light:dark cycle.”

“For cell collection during the dark phase of the circadian cycle, mice were randomly assigned to circadian time groups at time of weaning and housed on the reversed 12:12 h light:dark cycle. Brain dissections for all groups took place in the morning.”

My questions:

  1. What’s the clock time when the light is on/off in the animal facility for both the 14:10 and the reversed 12:12?
  2. Approximately what was the clock time in the morning when the brains were collected? (I understand that there’s may not be documentation on the exact time for all hundreds of animals, so an approximation would be fine for me.)

Thank you very much.

Have a great day,
Ka Yi HUI, PhD
University of Fribourg