Gene may regulate need for sleep

Fruit flies carrying a single point mutation in a gene for voltage-dependent potassium channels sleep for far fewer hours each day than wildtype flies, according to research published in the April 28 issue of Nature.

Giulio Tononi and colleagues from the University of Wisconsin, Madison, examined 9000 mutant lines of Drosophila melanogaster to search for genes that might explain why some individuals manage fine on just a few hours sleep each night.

Of 15 lines that slept at least two standard deviations less than the mean each day, the researchers chose the most extreme for further examination. In this line they found a threonine–isoleucine substitution in exon 9 of the Shaker gene, a region that is very well conserved in species ranging from Drosophila to humans.

Sleep is a complex phenomenon affected by the environment and probably many genes, but some are evidently more powerful than others, coauthor Ciara...