国产精品99一区二区三_免费中文日韩_国产在线精品一区二区_日本成人手机在线

Clues to aging found in stem cells' genomes: study

Source: Xinhua| 2018-02-14 06:20:30|Editor: yan
Video PlayerClose

CHICAGO, Feb. 13 (Xinhua) -- Stem cells that produce sperm use a genetic trick to stay perpetually young across generations, researchers at the University of Michigan (UM) Life Sciences Institute have discovered.

The results have been newly reported in the journal eLife.

Certain sections of the fruit fly genome get shorter with age. But remarkably, some reproductive cells can repair the shrinkage, and this genomic shrinkage may underlie aspects of aging and hint at ways that select cells might thwart it.

In the study, UM researchers focused on workhorse genes encoded in ribosomal DNA, or rDNA. These genes carry instructions for the parts that make up ribosomes, cellular machines that turn RNA molecules into every protein needed in the body.

In fruit flies, chains of rDNA genes are found on the X and Y chromosomes. Compared with young male fruit flies, old males had a shortage of rDNA genes on the Y chromosome, leaving them with a shrunken Y chromosome.

Moreover, this dearth of rDNA seems to be passed on from generation to generation. Geriatric fly fathers, those 40 days old, passed on their reduced number of rDNA genes to their sons, UM researchers found. These sons had considerably fewer copies of rDNA genes than sons born to younger fathers.

Then the researchers saw something surprising. In many cases, this rDNA loss reversed itself. At about 10 days of age, sons born to old fathers had recovered enough rDNA to be comparable to sons born to young fathers.

"This recovery was something we really didn't expect," said UM Life Sciences Institute faculty member Yukiko Yamashita.

The results suggest that rDNA rejuvenation in sons might be a crucial aspect of how stem cells persist from father to son. The researchers do not yet know whether such a reset can happen to female stem cells in the ovaries.

Until now, researchers had observed the phenomenon only in yeast. If the results hold true for humans, they could offer insight into how most cells deteriorate over time.

Being pushed, Yamashita would wager that some types of immortal cells in people can perform the same rejuvenating trick to prevent the rDNA declines that come with age.

TOP STORIES
EDITOR’S CHOICE
MOST VIEWED
EXPLORE XINHUANET
010020070750000000000000011105521369738901
主站蜘蛛池模板: 合江县| 福鼎市| 延川县| 贵定县| 德江县| 正镶白旗| 浦城县| 武乡县| 达尔| 普宁市| 玉山县| 黄龙县| 杭锦旗| 通江县| 山阴县| 双辽市| 新邵县| 惠安县| 广州市| 白水县| 五河县| 若尔盖县| 宜宾市| 桓仁| 工布江达县| 张家界市| 宁海县| 灌云县| 汶川县| 辉南县| 民和| 秀山| 民丰县| 民县| 江阴市| 富川| 芜湖市| 宁明县| 墨江| 磐安县| 常宁市|