Share on FacebookShare on TwitterShare on RedditEmailPrintShare via
Credit: ISTOCKPHOTO/JHORROCKS
For something so essential and basic, sleep has turned out to be a complicated biological nightmare for scientists. Certain genes, such as
and BMAL1, have been pegged for their roles in the body's circadian rhythm, but the full cast of characters involved in moderating
remains fuzzy.
But thanks to a mother and daughter who share a rare genetic mutation&and who routinely need just six hours of sleep a night&researchers have recently taken a step forward in the journey to unravel the tangled genetic web of sleep.
The new study, published online today in , reports the discovery of a genetic mutation on the gene DEC2 that appears to allow the mother&daughter pair of &short sleepers&&and a handful of transgenic mice&to truly need less sleep.
&We know sleep is necessary for survival,& says co-author , a professor of neurology at the University of California, San Francisco. But, &we don't know anything about how it's regulated,& she adds.
Sleep requirements seem to follow a typical curve in the general population, with most people needing between seven and eight hours nightly. Only about 5 percent of the population can get by just fine on six hours of sleep, notes Fu.
&In normal sleepers, if you reduce their duration to six hours, after a few days you will see some negative impact,& explains , an associate professor at the Center for Integrative Genomics at the University of Lausanne in Switzerland, who wrote the accompanying perspectives piece and wasn't involved in the study. &And no one should
him or herself.&
Despite only getting an average of 6.25 hours of sleep a night in the study, both the 17-year-old daughter and the mother in her late 40s seemed to be perfectly healthy and well-rested, Fu notes. &They feel just fine,& she says. Unlike the rest of their family members (who
an average of about eight hours of slumber), they had a mutation on the DEC2 transcription facilitator, which is involved in the , among other functions. But was this the sole cause of the curtailed sleep needs?
To further investigate the gene and its impact on the body, the researchers studied transgenic mice with the introduced mutation. These experimental animals experienced a daily activity period about 1.2 hours longer than their nonmutant compatriots. Removing Dec2 in mice, however, did not generate the same wakefulness, and instead the genetic knockout mice actually slept a little bit more.
The underlying question, Tafti says, is how much sleep do people really need? Could most people do just fine on seven hours or do some really need to slumber for a full nine? In order to sleep less, people would need to sleep better&that is, more efficiently, with more intense REM states, Tafti explains, which appears to be happening in those with the DEC2 mutation. &We believe that short-sleepers have more efficient sleep,& he says.
Even though this mutation is exceedingly rare, even in short-sleepers (Tafti estimates the total at less than 1 percent of short-sleepers), and it didn't turn up in any of the 250 control individuals tested), Fu is still hopeful that the discovery will pay off in the future. She says the find is &an opportunity to start looking into the pathways and whether we can modify that in the future.& Indeed, she and her colleagues are already investigating other genes.
Tafti expects a long road still ahead before scientists solidly understand sleep. &It's a complex phenotype,& he says, which is &probably the result of many, many genes&and the environment.&
In the future discoveries like this one may play a role in developing treatments for those who have sleep disorders, or just help regular people get by with less sleep. &Decades from now, we can act on that pathway and make sleep more efficient,& Tafti notes.
Fu says helping people sleep a little less while
and well-being is her ultimate dream.
ABOUT THE AUTHOR(S)Katherine HarmonRecent ArticlesEvery Issue. Every Year. 1845 - PresentNeuroscience. Evolution. Health. Chemistry. Physics. Technology.
& 2016 Scientific American, a Division of Nature America, Inc.All Rights Reserved.Don’t talk here.Grandparents _____.选择一项：a.sleeping b.are sleeping c.sleep d.is sleeping Who _____ English best in your class?选择一项：a.speaking b.speak c.speaks d.spoke Only through hard work can you ________ success in your career.选择一项：a.fulfill b.achieve c.finish d.get Children like going to the zoo,because they always ________ zoo with endless fun.选择一项：a.associate b.connect c.join d.link My hometown has undergone tremendous economic and social _______ over the past ten years.选择一项：a.transmission b.transformation c.transfer d.transportation There ____________ a telephone call for you in five minutes.选择一项：a.was b.is c.had been d.will be Mrs.Read _____ the windows every day.选择一项：a.cleans b.cleaned c.is cleaning d.clean Kungfu Panda is a very _________ to watch.选择一项：a.amused b.fun c.happy d.amusing The ________ of the scientific attitude is that human beings can conquer nature.选择一项：a.key b.essence c.heart d.soul Excellent essays should be chosen for the students to recite and ________ to gradually improve their linguistic skills.选择一项：a.copy b.remember c.imitate d.exercise The last time I ___ Julia she ___ apples in the woods.选择一项：a.saw,picked b.saw,was picking c.had seen,was picking d.had seen,picked The money you _______ will help the children in this area to go to school.选择一项：a.dedicate b.contribute c.supply d.devote Doctors find a _______ between skin cancer and the length of time spent in the strong sunshine.选择一项：a.relative b.associative c.connection d.combination A friend in deed _______ you when you are in trouble.选择一项：a.stands for b.stands out c.stands up to d.stands up for –May I speak to Dr.Hanson?--_________.选择一项：a.No,you can’t.b.Yes,speaking.c.Yes,it’s me.d.Sorry,you can’t.Peter started to learn Chinese Tai Ji last year and now he _______ it every day.选择一项：a.had practiced b.will practice c.has practiced d.practices
狮子爱3983
20-25:BCBABD26-30:ADACB31-35:BCDBD
为您推荐：
其他类似问题
20-25:BCBABD26-30:ADACB31-35:BCDBD希望对你有帮助。。。
题目20Don’t talk here. Grandparents _____.选择一项：a. sleeping b. are sleeping c. sleep d. is sleeping Suggested Answer:B题目21Who _____ English best in your class...
扫描下载二维码在线求指导：My grandpa is sleepi
My grandpa is sleeping.Will you please_____the radio?
A.turn down B.turn up C.turn on
为您推荐：
其他类似问题
扫描下载二维码Don’t talk here. Grandparents ____.A. sleepB. is sleepingC. are sleepingD. sleeping
凝帝系列367hNm
答案C此处需用现在进行时：be＋现在分词,因为主语是第三人称复数,故选C
为您推荐：
其他类似问题
扫描下载二维码