It is reported that the laboratory mouse, possesses telomeres up to 10 times longer than those of humans (30–150 kb in mice versus 10– 15 kb in humans). And it is reported that mice have average 7,000bp/year attrition, humans have 70bp/y attrition. How could this be possible that mice have 100 times telomere attrition than human cells? I am not the specialist of this field, welcome anyone to comment and give me suggestions.
Hello Ruicong Wang
In mammals, telomere length inversely correlates with lifespan and telomerase expression inversely correlates with body mass, indicating that telomeres serve different purposes in different species and that telomere elongation and telomerase activation may represent an adaptive evolutionary advantage of small short-lived mammals in exchange for energy-expensive oxidative DNA damage mechanisms. Short-lived species with small body mass, like mice, evolved to have much longer telomeres and express telomerase at the expense of abandoning a role of telomeres in replicative aging.
You can refer to the articles below for more detailed information.
Article Telomere Dynamics in Mice and Humans
Article Coevolution of telomerase activity and body mass in mammals:...
https://pubmed.ncbi.nlm.nih.gov/9560153/
Chapter Evolutionary Origins of Aging
Hope this helps you !
Best Wishes.
Fascinating topic. My guess is that lab mice are not like their wild type counterparts and have been bred for a very long time with the focus on fecundity. This has altered some important aspects of the biology of telomers, and lab mouse tellers may be an artifact of captivity (Article Wild-derived inbred mouse strains have short telomeres
).The JAX website further explores this original observation and comes to this conclusion:
"Further inquiry at JAX, in its efforts to fully characterize the mice it uses in its own research and distributes to the global biomedical community, has revealed that telomere length varies between mouse species and subspecies. Length is not determined by whether a mouse is inbred or wild-derived, and it is not affected by how long an inbred strain has been domesticated. Indeed, various wild-derived mice have telomeres that are shorter or longer on average than those of C57BL/6J, one of the original inbred mouse strains. And, as Greider hypothesized 20 years ago, telomere length does not predict lifespan."
Since I am also not a specialist in this field, I still find it interesting that telomer length is so flexible. Perhaps it is a similar "problem" as we can see with the association of body mass and longevity. comparing species: the bigger you are, the longer you live; but within a species: the taller and bigger you are, the shorter your life expectancy.