FLICKR, JULIE VACCALLUZZOHuman volunteers following a 28-hour sleep-wake cycle expressed far fewer genes in a typical circadian cycle, according to a study published today (January 20) in PNAS. And among the genes that showed aberrant expression cycles were those involved in transcription and translation, pointing to mistimed sleep as a major contributor to the physiological effects of shiftwork and jet lag.
“I think that’s quite new and intriguing,” said neurobehavioral geneticist Valter Tucci at the Italian Institute of Technology in Genova, who was not involved in the study. “The shifting the time of sleep has enormous consequences. Just by looking at the genes, we see most profound disruption.”
In the 1930s and ’40s, circadian research pioneer Nathaniel Kleitman found that, when he forced himself to follow a sleep-wake cycle of 28 hours, his body temperature would not fluctuate as much as it did on a normal, 24-hour cycle. Other physiological rhythms also “have a reduced amplitude in general when you’re not sleeping at the right time of day,” said Derk-Jan Dijk, a sleep physiologist at the University of Surrey, who noted that such disturbed rhythms are ...
