Researchers from Tufts School of Medicine discovered a gene that is required for normal sleep patterns in fruit flies, which scientists think could provide future insights into the science of human sleep.
Rob Jackson, a professor of neuroscience at the School of Medicine, leads a lab that has been studying circadian rhythms and their genetic basis for more than thirty years. He uses fruit flies—Drosophila melanogaster is the scientific name—to study the phenomenon, since they have twenty-four-hour circadian clocks and sleep cycles similar to those of humans. “Remarkably, many of the genes underlying their rhythmic behaviors have human counterparts,” he said.
Today the researchers report in a study published in Current Biology that a gene they named Noktochor (NKT) is expressed at high levels in fly astrocytes and is required for normal sleep patterns. Noktochor, which means “nocturnal” in Bengali, is not required during fly development, but is necessary in the adult brain for maintenance of healthy sleep, “suggesting a physiological function in adult flies,” said Jackson.
Fruit flies that lack NKT gene expression have decreased night sleep, while their sleep during the day is normal—and yes, flies take afternoon naps. The NKT gene is expressed at high levels in fly astrocytes and at low levels in their neurons, and is required in both cell types for normal night sleep.
Although there is not a human NKT gene, similar astrocyte-neuron communication mechanisms exist in flies and humans, and human astrocytes are known to regulate sleep and circadian behavior.