Edible dormice: The older they get the more they rejuvenate their cells

November 24, 2016

The shortening of telomeres in cells was thought to be an important biomarker for lifespan and aging. The edible dormouse (Glis glis), a small hibernating rodent, now turns everything upside down. In contrast to humans and other animals, telomere length in the edible dormouse significantly increases in the second half of its life, as researchers from Vetmeduni Vienna found out just recently. The study was published in Scientific Reports.

"As far as I know, no previous study has reported such an effect of age on telomere lengthening," says Franz Hoelzl, one of the authors. Apparently, this unique pattern is due to the peculiar life history of this species. They can reach maximum lifespan of 13 years, which is a Methuselah-like age for a small rodent. "This extreme lifespan is almost certainly related to their ability to rejuvenate telomeres", says Hoelzl. Telomeres are the endcaps of chromosomes, which prevent, together with proteins, the degradation of coding DNA sequences.

Telomeres in small animals shorten fast, but in edible dormice they even grow

In normal somatic cells, telomeres are shortened with every cell division. Besides, oxidative stress has a strong effect on telomere erosion. However, the rate of telomere shortening differs between species. For instance, it has been shown before that telomeres in fast-aging, short-lived wild animals erode more rapidly than in slow-aging, long-lived species.

Earlier this year, the author Franz Hoelzl and his colleagues from Vetmeduni Vienna showed that edible dormice has the capability to re-elongated its telomeres, given that food availability is high. This finding raised the question about the long-term balance between telomere attrition and repair.

The relative telomere length (RTL) gave evidence

To find an answer, the team started a long-tem study on changes in telomere length. In the Vienna Woods in Austria they regularly checked 130 nest-boxes that are occupied by free-living dormice. The researchers collected the rodent's buccal mucosa for three years. Thus, they could extract the DNA and determine the relative telomere length for each dormouse individually using qPCR. With this method scientists can define the amount of target DNA compared to a reference gene of the same sample.

Elongation does not only occur, it even increases in older edible dormice

"We found out that the telomeres were shortened in young animals but length significantly increased once the dormice were six years old or older. To top it all, the rate of telomere elongation also increased with increasing age of the dormice", says Franz Hoelzl.

Among the variables tested, only age significantly affected RTL in a non-linear pattern with telomere length decreasing in younger and increasing in older dormice. Hoelz says, "Telomere length was not affected by time of the year, sex, body mass or reproductive activity at the time of sampling." Nevertheless, the analysis of long term reproduction-data of the same population shows that the probability to reproduce also increases with age. This finding could indicate that telomere elongation is actually part of the preparation for upcoming reproductive events, as gestation and lactation could increase oxidative stress and the animals may attempt to protect their genome.
-end-
Service: The article "Telomeres are elongated in older individuals in a hibernating rodent, the edible dormouse (Glis glis)" by Franz Hoelzl, Steve Smith, Jessica S. Cornils, Denise Aydinonat, Claudia Bieber and Thomas Ruf will be published embargoed in Scientific Reports (Nature Publishing Group) today, 24th of November. Embargo ends at 11:00am CET.

About the University of Veterinary Medicine, Vienna

The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at

Scientific Contact:
Franz Hölzl
Research Institute of Wildlife Ecology
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-7273
franz.hoelzl@vetmeduni.ac.at

Released by:
Georg Mair
Science Communication / Corporate Communications
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1165
georg.mair@vetmeduni.ac.at

University of Veterinary Medicine -- Vienna

Related Telomeres Articles from Brightsurf:

Born to be young?
The environment we experience in early-life is known to have major consequences on later-life health and lifespan.

Scientists home in on the mechanism that protects cells from premature aging
A new study by EPFL researchers shows how RNA species called TERRA muster at the tip of chromosomes, where they help to prevent telomere shortening and premature cell aging.

The CNIO discovers that rapamycin has harmful effects when telomeres are short
The CNIO shows that an anti-aging strategy that extends life in normal mice, the treatment with rapamycin, is harmful when mice have short telomeres.

Drinking 1% rather than 2% milk accounts for 4.5 years of less aging in adults
A new study shows drinking low-fat milk -- both nonfat and 1% milk -- is significantly associated with less aging in adults.

Crick researchers unravel protective properties of telomere t-loops
Loops at the ends of telomeres play a vital protective role preventing irretrievable damage to chromosomes, according to new research from the Crick.

CNIO researchers obtain the first mice born with hyper-long telomeres
Mice with hyper-long telomeres live, on average, 13% longer and in better health, free from cancer and obesity The study has found for the first time ever a clear relationship between the length of telomeres and insulin and glucose metabolism, which are also crucial in ageing 'This finding opens the interesting hypothesis that genes are not the only thing to consider when it comes to determine species longevity,' indicates Maria Blasco, senior author of the paper.

Gene coding error found in rare, inherited gene cof lung-scarring disorder linked to short telomeres
By combing through the entire genetic sequences of a person with a lung scarring disease and 13 of the person's relatives, Johns Hopkins Medicine researchers say they have found a coding error in a single gene that is likely responsible for a rare form of the disease and the abnormally short protective DNA caps on chromosomes long associated with it.

A single change at telomeres controls the ability of cells to generate a complete organism
Pluripotent cells can give rise to all cells of the body, a power that researchers are eager to control because it opens the door to regenerative medicine and organ culture for transplants.

Cold-parenting linked to premature aging, increased disease risk in offspring
New research out of Loma Linda University Health suggests that unsupportive parenting styles may have several negative health implications for children, even into their adult years.

Pitt study finds direct oxidative stress damage shortens telomeres
First causal evidence that oxidative stress works directly on telomeres to speed cellular aging.

Read More: Telomeres News and Telomeres Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.