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These Genes May Control Whether You're a Morning or Night Person

FIONA MACDONALD
18 MAY 2015

Here's some good (and bad) news for all you night owls desperately trying to get better at mornings - new research suggests that it's not your fault that you can't string a sentence together before 9am. You may simply be genetically predisposed to being more productive at night-time.

 

After investigating the genomes of fruit flies, researchers from the University of Leicester in the UK have identified nearly 80 genes that are linked to a preference for either 'morningness' or 'eveningness'. And although that may sound pretty unrelated to your own body clock, the team showed that most of these genes are found in mammals, too.

Previous research has demonstrated that most people find they're most productive either early in the day or late at night - a preference that's known as a 'chronotype'. And while a lot of studies have looked into the effects of this chronotype, there hasn't been much investigation into what actually causes these differences, up until now.

"In this new study, we have used fruit flies [Drosophila melanogaster], whose gene clocks are very similar to [a] human's, to get a first insight into the molecular basis of ‘morningness/eveningness’ preference," explained team member Eran Tauber in a press release. "Because this genetic system is so similar between insects and human[s], there is a good chance that some of the genes that we have identified in flies, would be also important for diurnal preference in humans."

As part of their research, the team identified two different fly strains that were at their most active either in the morning, or the evening, and they then compared and contrasted their genes. They found nearly 80 genes that appear to be linked to the flies' chronotypes, but interestingly, these genes aren't ones that are known to regulate our body clock. Instead, they're involved in a range of molecular pathways.

"This changes our view of the body clock, from a pacemaker that drives rhythms to a time reference system that interacts with the environment," said one of the lead researchers, Ezio Rosato, in the release.

Even more interesting was the fact that the molecular processes in the 'night owl' flies weren't just delayed compared to the morning lovers - they were entirely different.

"I refer to this behaviour as the 'pinball theory'," said Tauber. "Once a gene expression is delayed (in larks), a completely different cascade of molecular events is carried, similar to the ball in a pinball machine that takes a different route in each run. The end point might be similar, but the different molecular routes result in a different journey time."

The researchers have published their findings in the journal Frontiers in Neurology, and will now investigate where these genes are involved in similar processes in humans.

The ultimate goal is to find potential targets for treatments that could help people overcome their evening or morning chronotype. While that sounds a little extreme, it could help prevent a range of disorders, such as obesity and depression, which have been linked to a lifestyle that's out of whack with your body clock.

"The rhythm of life is such that for many people the economic or social call to start a new day comes hours before the endogenous call from the body clock. This creates a clock dysfunction that is not only reflected in temporal disorientation and sleep problems, but also in conditions such as obesity, mental illness, cardiovascular disease and cancer," said Taubler.

"Our study is the first stepping stone to identifying which genes are involved in this process. This will allow better diagnostics, and ultimately personal medicine, where larks and owls will receive their tailored therapies."

While I'm not sure I'm ready for medication to help turn me into a morning person just yet, I kind of love the fact that researchers are finally revealing that, biologically, not everyone can function on a 9 to 5 schedule.