Scientists have discovered more evidence that it’s importance to keep our biological clocks in sync with our environment. Our circadian rhythms are the internal 24-hour biological clock in our bodies. This internal clock regulates many biological processes such as our metabolism. Numerous studies have shown that when our circadian rhythms become out of sync with the natural day-night cycle — such as when working third-shift, experiencing jet lag, or not sleeping regularly – there is increased risk of disease. However, the genetics behind this is not clear.
Importance of a Synched Internal Biological Clock
Scientists at the University of California San Diego have discovered that the importance of circadian rhythms matching the natural day-light cycle hold for even photosynthetic bacteria called cyanobacteria, or “blue-green algae.” Their study was published in the journal Nature Communications.
Bacteria Incorporate DNA Mostly During Night Phase
Bacteria incorporate new DNA materials into their own DNA to keep up their genetic diversity. This ability to take up DNA is typically tightly regulated. The researchers identified the DNA uptake machinery in the bacteria (called cyanobacterium Synechococcus elongates) and discovered that the internal circadian clocks within their cells prevent DNA uptake early in the day and enhance the process early at night. In other words, the bacteria tend to take in more DNA material during the night cycle.
Risks From Disrupted Circadian Rhythms
The researchers found that when “night time” does not match with the bacteria’s internal clock time, then this DNA uptake does not provide a boost in DNA uptake and incorporation. This is a striking example how a biological process needs the internal clock of an organism to match with the natural day-night cycle.
“I think this paper demonstrates the importance of having internal biological time coincide with environmental time,” said Susan Golden, the senior author of the paper.
“There are lots of human illnesses in which people are poorly aligned to their environment. This can result from habits such as getting too much light at night, eating at odd times of the day and not sleeping regularly. In the cyanobacterium it makes a very big difference for biological time and external environment time to be aligned,” she said.
The results also implicate the importance of keeping the internal biological clocks of human aligned with the natural day-light cycle. Disrupting our circadian rhythms for long periods of time can have implications, especially with higher risk of disease.