The Extraordinarily Long-Lived Edible Dormouse

   The unusually named, hibernating edible dormouse actually lengthens its telomeres in the later half of its life, and lives an impressive maximum of 13 years

Telomere loss is one of the major hallmarks of aging, and has been shown to be present in a majority of animals as they age. The diminutive, edible dormouse however (also known as Glis glis) appears to buck the trend by extending its telomeres in the latter part of its life. The startling finding suggests this unique ability may be behind its surprising longevity; a maximum of 13 years, which is highly unusual for a small rodent.

Back to the telomere question

While this is still great debate around whether telomere shortening is a cause of result of other pathological processes that build up gradually as we age, a considerable amount of research is now highlighting the importance of these chromosomal caps. It was once feared that telomere extension could lead to rampant cancer, but while there is still an attached risk, in older animals at least telomere extension appears to cause real health improvements - especially prominent in JB Bernardes et al. in 2012. In this study involving more ordinary mice, telomere extension via gene therapy extended lifespan by up to 24% and improved multiple markers of health. Research is generally affirming how important keeping one's telomeres at a sufficient length is to maintaining healthy tissue replenishment and cellular health. 

The curious case of the edible dormouse

Previous research has shown that in short lived, small mammals telomere length is quickly eroded in contrast to long-lived species like humans. Mice begin life with longer telomeres than humans, but these appears to dwindle very quickly. However, researchers at Vetmeduni Vienna have discovered that edible dormice do not conform to this trend. After collecting the buccal mucosa from a large number of mice living in 130 nest boxes in the Vienna Woods, they determined average telomere length using qPCR. 

An edible dormouse in a hibernating state

"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" 

The researchers found an expected decline in telomere length in young dormice, but this paradoxically began to change in older mice. Much to the team's surprise, older mice appeared to be lengthening their telomeres consistently providing their had enough available food. Length was not linked to time of the year, sex or body mass. The researchers do note however that analysis of the data reveals that older dormice actually are more likely to reproduce than their younger peers. This suggests this exceptional telomere lengthening strategy may have evolved to protect the genome in preparation for reproduction. 

"As far as I know, no previous study has reported such an effect of age on telomere lengthening. 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"

It's not definitively clear that this species' long life is connected to this ability, but it's likely it plays a sizeable role. This suggests once again that telomere extension could be a valid route within a multi-pronged rejuvenation strategy. 

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