A new model, published October 27 in Current Biology, has some new ideas surrounding bacteria and aging. In fact, it goes against everything we’ve always thought about bacteria, namely that they do not age.
Could it be??
In 2005, researchers in France showed that dividing bacteria produce two daughters that replicate at different rates—the first solid evidence for asymmetric division.
“The finding implied that one offspring was taking a hit, retaining the damaged proteins that prevented it from replicating as quickly as the other, ‘renewed’ daughter cell. In other words, it was aging.”
Then, last year (2010), researchers at Harvard seemed to prove the exact opposite; concluding that “a ‘mother’ E. Coli bacterium could divide a hundred time and not show signs of aging.
So which is it?
It may indeed be both.
In an online article published in The Scientist, when Chao re-analyzed both studies, he realized both sets of data fit his mathematical model.
The offspring of a mother that divided asymmetrically into faster and slower-growing daughters would have a higher overall fitness than a mother that divided symmetrically. In addition, while some offspring would reproduce faster than others, they would only speed up to a certain point—an equilibrium point. The slow reproducing offspring, likewise wouldn’t decrease reproduction rate indefinitely; they would never stop dividing altogether. So the lineage produced by the exponential divisions of a single cell could “reach a immortal state” despite the fact that it was dividing asymmetrically, and producing daughter cells that “age,” said Chao.
Read more on bacterial rejuvination and what it means for us at: