hair follicles

これ、へえ〜という感じでした。人ごとではない。そうだろう太郎君！camelくん、太字を説明してください。（小山本）
Researchers find hair follicles are watching the body's clock
Researchers have developed an easy method of measuring the patterns of "clock genes" -- genes that regulate the body's circadian rhythms -- using hair follicle cells.
Disturbances in the circadian rhythm have been connected to health problems including diabetes and high blood pressure, and the research team led by Makoto Akashi of Yamaguchi University hopes their method can be put to use in doing away with jet lag and other practical applications.
"We hope our research will be useful in improving working conditions and help in the prevention and diagnosis of illnesses caused by disruptions of the circadian cycle," Akashi said.
There are some 20 internal clock genes, present in tissues throughout the body. Until now, researchers had used cells taken from blood or mucous glands in the mouth to analyze the genes -- methods that were both invasive and inaccurate.
Akashi and his team focused instead on follicle cells on hair plucked from the heads and chins of test subjects. When measuring the increases and decreases in messenger RNA produced through the clock genes, the researchers saw that the activity of three genes in particular changed in precise patterns based on a 24-hour cycle.
The team found that the peak of messenger RNA expression responded to the lifestyles of the subjects, as well as changes in those lifestyles. The earliest peak of clock gene expression was seen in the earliest riser among the four subjects, while when the same subjects were asked to shift their wake-up time forward by four hours over three weeks, the gene expression rhythm also shifted, though by nearly three hours instead of four.
The team also studied six auto parts factory workers in their 20s and 30s who were on the 6 a.m. to 3 p.m. shift one week, the 3 p.m. to midnight shift the next week, and then back to the early shift the following week. They found that despite seven-hour shifts in their sleeping and waking patterns, the activity of the circadian genes in their follicle cells shifted by only two hours, meaning the workers essentially suffered from chronic jet-lag.
The researchers now plan to investigate how shifts in circadian gene expression are tied to ailments such as high blood pressure and diabetes. The team's findings were published in the Proceedings of the National Academy of Sciences on Aug. 23.
http://mdn.mainichi.jp/mdnnews/news/20100824p2a00m0na003000c.html