17,00 genes vital to sleep identified

London, Feb 23 (ANI): In a study on the need for sleep in animals, scientists at North Carolina State University have identified almost 1,700 genes associated with the variability of sleep in fruit flies.

Led by Dr. Trudy Mackay, the study has shown that the fruit fly is genetically wired to sleep, although the sleep comes in widely variable amounts and patterns.

The researcher believes that understanding the genetics of sleep in model animals could lead to advances in understanding human sleep, and how sleep loss affects the human condition.

During the study, the research group examined the sleep and activity patterns of 40 different wild-derived lines of Drosophila melanogaster, one of the model animals used in scientific studies.

The researchers observed that male fruit flies on average slept longer than females, males slept more during the day than females, and males were more active when awake than females.

The females, in turn, tended to have more frequent bouts of sleep, and thus were disrupted more from sleep, than the males.

The researchers closed down on almost 1,700 genes linked with variability of sleep in fruit flies, most of which were previously not known to affect sleep.

Mackay said that fruit flies within each of the 40 lines were homozygous, or exactly the same genetically, but the lines were completely different from one another.

For the study, the researchers placed small glass tubes containing one fruit fly and some food in a machine, which used infrared sensors to monitor the minute-by-minute activity of the flies.

If at least five minutes passed without any fly activity, it was calculated as sleep.

The study predicted that certain important genes would affect sleep duration, and independent verification with mutations in those genes was found to have an effect on how long fruit flies slept.

The study also discovered teams of genes that appeared to act together to affect some portion of sleep.

"We're starting to get a glimmer of how groups of correlated genes are overrepresented in different traits, and we now know more about how traits are associated with each other at the molecular level," Nature magazine quoted Mackay as saying.

The study has been published in the online edition of the journal Nature Genetics. (ANI)