Chrono, the last piece of the circadian clock puzzle?

This article talks about how all organisms have a daily cycles that are regulated by the circadian clock. This internal clock is best known for its ability to be influenced by exposure to light which controls the wake-sleep cycle. The clock that controls such an activity is controlled by genes and proteins that interact and turn each other on and off based on the environment.

A team from RIKEN, Hiroshima University, and University of Michigan conducted a study in order to uncover a missing component. The researchers decided to perform a genome-wide chromatin immunoprecipitation analysis for genes that target a core component of the clock genes, called BMAL1. From this, the authors discovered a new circadian gene which functions as a transcriptional repressor of the negative feedback loop in the mammalian clock. This protein, which they named CHRONO, was shown to alter the expression of core clock genes in mice that lacked the gene. This resulted in longer circadian cycles.

The article also states that the study demonstrated "that the repression mechanism of CHRONO is under epigenetic control and links, via a glucocorticoid receptor, to metabolic pathways triggered by behavioral stress."

The sleep cycle is not well understood in the scientific world, and while this research doesn't pinpoint exactly why we sleep it does offer some preliminary insight on the mechanisms of why we sleep when we do and how the mechanisms function as a unit to control the internal clock. Continuing research could reveal some interesting findings of our circadian clock and sleep cycles.