Circadian rhythms are biological rhythms that cycle over a period of about 24 hours and regulate timing for most physiological functions and behaviors such as sleeping, eating and activity. As a checks-and-balances procedure, Ptitsyn analyzed the sets of data with several mathematical approaches to achieve
the same results. The research also shows that gene oscillation is significantly more organized when mammals are exposed to regular periods of day and night. Oscillation can become chaotic in states of consistent lighting or lack of lighting, but it never stops.
Comparing the complex system in which the genes function to an AC power grid, Ptitsyn made the discovery by plotting the expression of 20,000 genes on a scale of frequency, or intensity, over a two day period and sorting them by phase or timing of oscillation. Where previous studies have failed, the Colorado State study uses advanced algorithms that have the capacity to identify patterns in such a large number of genes.
Ptitsyn discovered that gene activity oscillates in a "finely orchestrated" system and gene expression can be impacted by daylight and darkness -- or a lack of both. For example, while gene expression oscillates in mice exposed to a constant state of dim light or darkness, the groups of genes that typically oscillate together -- such as genes responsible for the function of an organ or a specific tissue -- are chaotic under this state and don't function as a group. Lack of orchestration can be easily confused with the lack of oscillation. This makes the rhythm much h
Source:Public Library of Science