Data from: Differential phasing between circadian clocks in the brain and peripheral organs in humans

The daily timing of mammalian physiology is coordinated by circadian
clocks throughout the body. Although measurements of clock gene expression
indicate that these clocks in mice are normally in phase with each other,
the situation in humans remains unclear. We used publicly available data
from five studies, comprising over 1000 samples, to compare the phasing of
circadian gene expression in human brain and human blood. Surprisingly,
after controlling for age, clock gene expression in brain was
phase-delayed by ~8.5 h relative to that of blood. We then examined clock
gene expression in two additional human organs and in organs from nine
other mammalian species, as well as in the suprachiasmatic nucleus (SCN).
In most tissues outside the SCN, the expression of clock gene orthologs
showed a phase difference of ~12 h between diurnal and nocturnal species.
The exception to this pattern was human brain, whose phasing resembled
that of the SCN. Our results highlight the value of a multi-tissue,
multi-species meta-analysis, and have implications for our understanding
of the human circadian system.