The naked mole rat ( Heterocephalus glaber ) has some pretty strange, if not incredible qualities, including full immunity to cancer or the ability to live up to 18 minutes without oxygen. Now, a team of researchers from Google’s Calico Labs biotech company has discovered that these animals don’t age either; their chances of dying do not increase as they age.
In any species of mammal, the risk of death continually increases over time. However, this does not happen with naked mole rats, a species of rodent that hides in the deserts of East Africa and considered in many places a pest because it feeds on roots and tubers.
Mortality
The mortality rate in mammals generally follows what is known as the Gompertz-Makeham mortality law, a mathematical equation that describes the increase in the mortality rate along with the increase in age after reaching adulthood.
In humans, the risk almost doubles every year after age 30. But things are completely different for these wrinkled hairless rodents.
“For me, this is the most exciting piece of information I have obtained. It goes against everything we know in terms of mammalian biology, ” explains Rochelle Buffenstein, leader of the work, who has been studying these animals for more than 30 years. carefully documenting every death of the rodents in your care.
After studying the records of 3,299 naked mole rats , he found that the mortality risk remained at around 1 in 10,000 for the rest of the rats’ lives.
Challenging the biological laws of aging
The naked mole rat reaches sexual maturity at six months of age. Based on their size, their average life expectancy in a laboratory is about 6 years, but some live for more than 30 years and are still able to reproduce.
“Our research shows that naked mole rats do not age in the same way as other mammals, and in fact show little to no signs of aging, and their risk of death does not increase even 25 times after their time to reproductive maturity.” Buffenstein said.
According to experts, these findings reinforce the belief that naked mole rats are exceptional animals that must be studied to further our understanding of the biological mechanisms of longevity.
It is unknown why naked mole rats have this incredible quality for life. A 2009 study proposed that there may be several causes: stable proteins that grow less than those seen in mouse models, and less oxidation than in other mammals.
It is clear that more studies will still need to be done in these types of animals to see if the trend continues after the age of 30. How long could they live? Will this species hold the key to longevity?
At the moment, the oldest naked mole rat currently living in Buffenstein’s lab is 35 years old.
Reference: Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age. J Graham Ruby, Megan Smith, Rochelle Buffenstein. Calico Life Sciences LLC, United States. Elife 2018. DOI: https://doi.org/10.7554/eLife.31157.001
