Daily Gene Expression Rhythms Vary with Sex and Age: Study on postmortem tissue

Amazing stuff! This may well impact e.g. the timing of medications.

"The mammalian circadian clock strongly influences when and to what extent certain genes are transcribed in each tissue throughout the day. A new study, ... shows that this daily schedule of gene expression depends partially on a person’s sex and age. Specifically, the team found that women have more genes with rhythmicity compared to men, and that these rhythms break down as people age. ...
begin to understand causal relationships between the circadian clock and human disease states, for instance, in cancer or metabolic disorders."

From the abstract:

"The circadian clock modulates human physiology. However, the organization of tissue-specific gene expression rhythms and how these depend on age and sex is not defined in humans. We combined data from the Genotype-Tissue Expression (GTEx) project with an algorithm that assigns circadian phases to 914 donors, by integrating temporal information from multiple tissues in each individual, to identify messenger RNA (mRNA) rhythms in 46 tissues. Clock transcripts showed conserved timing relationships and tight synchrony across the body. mRNA rhythms varied in breadth, covering global and tissue-specific functions, including metabolic pathways and systemic responses. The clock structure was conserved across sexes and age groups. However, overall gene expression rhythms were highly sex-dimorphic and more sustained in females. Rhythmic programs generally dampened with age across the body."

Daily Gene Expression Rhythms Vary with Sex and Age: Study | The Scientist Magazine® By studying tissues from deceased people, a team found that women have more rhythmical gene expression and that this molecular rhythmicity decreases with age.

Sex-dimorphic and age-dependent organization of 24-hour gene expression rhythms in humans (no public access)