Sydney, Jan 29: Scientists have found that genes can influence a person's preference for rising early.
According to study every cell in the body contains a clock and, in particular, shows that skin cells can be tested to reveal if a person has a genetic propensity to like lie-ins, burn the midnight oil or get up at the crack of dawn A simple skin test could reveal if someone who hates getting up is lazy, or whether their body clock is badly out of step with that of other people could help develop new treatments.
Prof Steve Brown and his colleagues at the Chronobiology and Sleep Research Group, University of Zurich, found that the brain's hypothalamus acts as a central clock for the body, but does so by synchronising all the individual cells, which have their own clocks.
Skin cells are much easier to study than the one in the brain the team collected the cells from 28 volunteers and inserted a gene that glowed into them creating biological clocks that waxed or waned in brightness over 24 hours.
The research showed that the skin cells from extreme early-risers had the shortest glowing periods, whereas those from very late-risers had the longest.
''They conclude in the Proceedings of the National Academy of Sciences that their work could lead to a clinical screen to identify treatments for patients with extreme circadian rhythms.
"People know whether they are larks or owls," says Prof Brown.
"The interesting part is that they are not all larks or owls for the same reason, and this research addresses the molecular cause of their early or late behaviour," the Telegraph reported as saying.
Once the cause of a sleep disorder has been accurately diagnosed, it is possible to test treatments on patients who all have the same underlying disfunction, a key step towards developing more effective treatments for body clock disorders.