A previously unknown gene that regulates body clocks in mammals may have a variant that makes a normal day up to 3 hours longer for the ones carrying it. Using mice, researchers discovered Fbxl3, and its variant Afh ("after hours") to be a body regulator.
Monitoring mice using a wheel, they discovered that some mice had a 27 hour day pattern. It is thought that this is governed on a cellular level by the genes that break down proteins. Afh-affected mice break them down slower, lengthening the body clock.
Lead researcher Dr. Patrick Nolan said "The internal body clocks of mice with the after hours gene run on a longer cycle than mice that have a normal copy of the gene, who like most of us live on a 24-hour-schedule."