During the day, the activity of our genes oscillates in two large waves, one in the morning, the other in the evening. But these waves, which are greater in women than in men, diminish with age, according to a study in the journal "Science".
It is a story of genes whose activity oscillates in our cells during the day and night. Forming two large waves, one in the morning, the other in the evening, the height of which varies according to our tissues. The group of genes involved differs according to our tissues. Moreover, these waves appear more pronounced in women than in men, but are blunted by age in both sexes.
These are, in essence, the findings of an unprecedented exploration of human tissues taken from 914 donors shortly after their death. Published in the journal Science on 3 February, this analysis reveals the inner workings of our circadian clock, the molecular gearing that tells our cells the time of day - so they can adjust their tasks to the needs of the body.
But why the name 'circadian' clock - from the Latin circa, 'near', and dies, 'day'? Because in our species, this clock is set to an average period of twenty-four hours and twelve minutes. However, this duration depends on the individual. In early sleepers, the clock is faster (its period tends towards twenty-three hours and thirty minutes); in late sleepers, it is slower (twenty-four hours and thirty minutes). Whatever our chronotype, our internal clock must be set to a twenty-four hour rhythm. To do this, it uses external synchronisers: daylight, the rhythm of our meals and our daily activities, etc.
Read the full article here (in French): https://www.lemonde.fr/sciences/article/2023/02/07/chez-la-femme-l-horloge-circadienne-plus-active-que-chez-l-homme_6160869_1650684.html