What can a blind cavefish tell us about circadian clocks?

Circadian clocks and a revolving planet go hand-in-hand. But why so many plants and animals have a circadian clock from an evolutionary perspective is relatively unknown. One way to find out is to study animals that live in non-rhythmic environments. And at the end of 2013, my team published a study on exactly that: the circadian clock of the Mexican blind cavefish, Astyanax mexicanus, from data collected in the laboratory and in the fishes’ natural habitat. We showed that these cavefish fish shows wonderful daily patterns of behaviour and gene expression, confirming that it has a functional circadian clock.

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Circadian clocks in the great outdoors

We’re all aware of our natural body clock pattern: some people are early birds, some people are night owls, a phenomenon known as your chronotype. You can override this with alarm clocks and coffee, which is especially important for shift workers. But have you ever noticed your chronotype shift when you go on holiday, especially when you holiday in the great outdoors?

Researchers from the University of Colorado wondered exactly that and described in 2013 interesting findings on the influence of natural and artificial light on human circadian clocks. Continue reading “Circadian clocks in the great outdoors”

Shifting your clock: shift work and the circadian clock

To many people, the phenomenon known scientifically as the circadian rhythm is bleeding obvious. We sleep in the night and are awake during the day, long-haul flights like those from the UK to Australia gives you jetlag, and night shifts are a right pain in the bum. Detailed explanations involving transcription-translation feedback loops and phase response curves don’t change those facts, they’re a fact of life when we live on a rotating world. But many scientists, myself included, are fascinated in the details, and some scientists, like Céline Vetter and colleagues at the Institute of Medical Psychology at Ludwig-Maximilian-University in Munich, use this eye for detail to find out how we might best cope with our biological timing in a 24-hour society.

Coffee: Are you an early bird or a night owl?

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