It’s all in the genes, they say. So much of who we are is determined, or at least influenced, by our genetic make-up – even the time at which we wake up. A new study has explained that being an early bird or a later riser might depend on one’s genes, and so, this ‘trait’ is part of the legacy your parents hand over to you. The findings have been published in the journal Frontiers in Neurology.
The authors of the study analysed the genetics that lead to the categorisation as a night owl and an early bird (referred to as “larks”) by studying fruit flies. These insects whose genetic variations were studied are considered model organisms with a similar genetic clock to humans. The scientists theorised that the genes controlling their “clock” might thus be comparative to ours.
Around 80 genes were spotted that are believed to be associated with the differences in sleeping time.
“Most people find that their performance is at peak at specific times of day,” explained Dr. Eran Tauber, one of the co-authors.
“The impact of this preference on health and behavior is well documented, but the molecular basis is largely unknown.”
The chronotype of the flies, that is, their inclination to sleeping at a specific time of the day/ night, was observed and recorded in terms of the time of the day they came out of their pupal case; some of them do so in the morning, while others prefer sleeping till later.
The researchers then successfully bred the sleepy heads to produce more of their kind of chronotypes – this is an indication of a possible genetic link to the behaviour as the parents have seemingly passed the trait to their offspring.
Thereafter, from a DNA analysis that was run on the fruit flies during the 24 hours prior to their emergence, the researchers found that different genes were involved for different times in the two chronotypes. As such, it was not the same genes that were expressed at different times for the two characteristics. This was explained in terms of genetic variations.
Tauber commented on this observation as follows:-
“looking at gene expression was only part of our research. An obvious question is what causes the different expression in the larks and owls. This difference is largely due to genetic variations in their DNA sequences – different gene versions that are present in larks and owls.”
This implies that the molecular processes behind the genetic clock in those with the propensity to wake up at a later time are entirely different, as opposed to the more restricted theory stipulating that the processes are only delayed.
“Once a gene expression is delayed in Larks, a completely different cascade of molecular events is carried… The end point might be similar, but the different molecular routes result in a different journey time,” Tauber explains.
The study puts into perspective how each individual might be different in terms of his genetic clock (and, hence with respect to his own genes) and is therefore most productive at other times compared to others. This would challenge the typical working hours which might be to the detriment of night owls.