The mechanism that controls the internal 24-hour clock of all forms of life from human cells to algae has been identified by scientists. Not only does the research provide important insight into health-related problems linked to individuals with disrupted clocks — such as pilots and shift workers — it also indicates that the 24-hour circadian clock found in human cells is the same as that found in algae and dates back millions of years to early life on Earth.
Two new studies in the journal Nature from the Universities of Cambridge and Edinburgh give insight into the circadian clock which controls patterns of daily and seasonal activity, from sleep cycles to butterfly migrations to flower opening.
One study, from the University of Cambridge’s Institute of Metabolic Science, has for the first time identified 24-hour rhythms in red blood cells. This is significant because circadian rhythms have always been assumed to be linked to DNA and gene activity, but — unlike most of the other cells in the body — red blood cells do not have DNA.
Akhilesh Reddy, from the University of Cambridge and lead author of the study, said: “We know that clocks exist in all our cells; they’re hard-wired into the cell. Imagine what we’d be like without a clock to guide us through our days. The cell would be in the same position if it didn’t have a clock to coordinate its daily activities.
“The implications of this for health are manifold. We already know that disrupted clocks — for example, caused by shift-work and jet-lag — are associated with metabolic disorders such as diabetes, mental health problems and even cancer. By furthering our knowledge of how the 24-hour clock in cells works, we hope that the links to these disorders — and others — will be made clearer. This will, in the longer term, lead to new therapies that we couldn’t even have thought about a couple of years ago.”