Are You Short Sleeper or Long Sleeper? Gene Has Made Choice
What time do you usually go to bed at night? Do you like to take asiesta? Have you been called lazy boy or girl when you were a child because you get up late?
Although most experts recommend that adults shall sleep for 7-9 hours a day, the best time to fall asleep is 10 to 12 p.m., and a nap would be better at 2 to 4 p.m., you may still have your own sleep mode. No matter how long you sleep or how you sleep, these habits may be "the default set" already written in your genes.
In 1909, Danish botanist Wilhelm Johannsen coined the word "gene" to describe fundamental physical and functional units of heredity, and up to now, more secrets about gene are uncovered as biotechnology, such as the gene-editing tool CRISPR-Cas9, advances. Today, let's take a look at the sleep-related genes that scientists have identified!
Short Sleep Gene
Adequate and effective sleep is essential to health. However, some people are born short sleepers. They neither want to sleep more, nor do they have any negative health effects in the case of short sleep.
In October 2020, the team of Yinghui Fu and Louis J Ptáček from the University of California published a research paper entitled Mutations in Metabotropic Glutamate Receptor 1 Contribute to Natural Short Sleep Trait in Current Biology. They found that two independent mutations in the GRM1 gene cause familial natural short sleep, and research proved that mice carrying both mutations exhibit behavior of short sleep.
In fact, this is not the first time the team has discovered the short sleep gene. Prior to this, they had reported genes such as DEC2, ADRB1 and NPSR1, which have even stronger effects than GRM1, but these gene mutations are very rare.
And the gene to be introduced next is much more common asabout one in five peoplein Europe contains this gene. Researchers from the University of Edinburgh in the UK and the University of Munich in Germany conducted a high-density whole-genome association study on 4,251 people in 7 European populations and found that a gene called ABCC9 has a certain effect on people's sleep. In Drosophila, individuals with RNA interference (knockout of their conserved ABCC9 homologue) suffer from insomnia in the first 3 hours of night compared with normal Drosophila. This study showed that an intron mutation of this gene affects approximately 5% of sleep time changes. The study was published in Molecular Psychiatry in January 2013 with the title A K(ATP) Channel Gene Effect on Sleep Duration: from Genome-wide Association Studies to Function in Drosophila.
Long Sleep Gene
Some people can get energetic for a little sleep, but some are not so lucky and need to sleep longer than most people. Masashi Yanagisawa's team from the University of Tsukuba, Japan, conducted an EEG/EMG-based random mouse screening study and found that splicing mutations in the Sik3 protein kinase gene can significantly reduce the total awake time. The research was published in Nature in November 2016 with the title Forward-genetics Analysis of Sleep in Randomly Mutagenized Mice.
Using forward genetics, the researchers first screened out a family of lethargic mice. The mice in this family were awake for only 8.7 hours a day, which was much shorter than the waking time of normal mice (about 13 hours).
So, what is the gene for lethargy? The researchers found that a mutation in an intron of a kinase gene called Sik3 in the sleepy family of mice was the cause of the phenotype. This mutation of Sik3 at the site recognized by the spliceosome in the intron results in an error in the mRNAsplicing ofthe Sik3, and ultimately results in a deletion of the Sik3 protein. The researchers used gene editing to create the deletion of the Sik3 gene in normal mice and the result was that the phenotype was the same as that of sleepy mice, which proved their assumptions.
Some people are accustomed to napping during the day, and some can't sleep at all. Recently, a study led by researchers from Massachusetts General Hospital (MGH) showed that how long a person sleeps during the day is controlled to a certain extent by his genes.
The team has previously identified genes related to sleep time, insomnia, and the tendency to get up early or stay up late. In this largest study to date, the MGH team worked with institutions such as the University of Murcia in Spain to identify dozens of genetic regions that control the tendency to nap during the day. They also found preliminary evidence that the siesta habit is related to cardiometabolic health.
After studying the data in depth, the research team discovered at least three potential mechanisms that lead to asiesta—sleep tendency, that is, some people need more sleep than others; sleep interruption, that is, nap during the day can help make up for the poor quality of sleep the night before; early risers, those who rise early may take a nap to make up for their sleep. This study was published in Nature Communications in February 2021 under the title Genetic Determinants of Daytime Napping and Effects on Cardiometabolic Health.
People are accustomed to using words like "self-discipline" or "lazy" to evaluate people with different sleep habits. But now, more and more scientific research tells us that different sleep patterns may be determined by genes, so this kind of evaluation maynot be accurate and fair. Differences should be respected. No matter how you sleep, getting adequate and efficient sleep and giving your body and brain a good rest is always the right thing to do.
Nu au fost inca adaugate firme in acest ghid.