Functional identification of the mouse circadian
Clock gene by transgenic BAC rescue.
Animal studies reveal that the
Clock gene controls the length of a period in a free-running rhythm and it allows an organism to maintain circadian rhythmicity in total darkness.
Interestingly, there is evidence that exposing cultured neural retinal cells of chicken embryos to cycles of light and dark triggers rhythmic expression of
clock genes (23).
While the
Clock gene is expressed throughout the brain, it's really only been studied in one particular brain region, which is the one that's involved in circadian rhythms," said Dr.
Since the discovery of the
Clock gene in mice, the list of circadian dock genes identified in mammals has grown in a remarkably short period of time (see table 1).
Musiek studied mice lacking a master
clock gene called Bmal1.
However, in-depth molecular studies are necessary to elucidate the potential mechanisms by which alcohol directly or indirectly affects
clock gene expression and cellular functions.
METHODS: Glucose tolerance, insulin resistance, and expression of peroxisome proliferator-activated receptor-[alpha] (PPAR-[alpha]) and genes affecting glucose metabolism or fatty acid oxidation and
clock gene rhythms were investigated in wild-type (WT) and AhR-deficient [knockout (KO)] mice.
The researchers exposed normal flies and flies lacking the
clock gene period to one day of high oxygen, which can set off harmful chemical reactions that damage DNA and proteins.
For instance, Stevens and colleagues at Yale including Yong Zhu found that healthy control women showed lower expression of the
CLOCK gene than women with breast cancer.
Estee Lauder scientists are among the first in skincare to understand the role of
clock gene activation and synchronization to enhance skin's natural repair activity.
We were amazed that our data revealed that
clock gene rhythms varied in synchrony across six regions of normal human brain and that these rhythms were significantly disrupted in depressed patients.
The study showed that when administered in animal models the synthetic small molecules altered circadian rhythm and the pattern of core
clock gene expression in the brain's hypothalamus, the site of the master cellular clock that synchronizes daily rhythms in mammals; circadian rhythms are the physiological processes that respond to a 24-hour cycle of light and dark and are present in most living things.
Mice with a mutated
Clock gene are obese and have features of metabolic syndrome, but they show relatively normal activity levels under normal light/dark cycles and show abnormal behavior only in complete darkness.
Georgios Paschos PhD, a research associate in the lab of Garret FitzGerald, MD, FRS director of the Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, found that deletion of the
clock gene Arntl, also known as Bmal1, in fat cells, causes mice to become obese, with a shift in the timing of when this nocturnal species normally eats.