A single-celled organism without a brain or nervous system could still form memories and pass those memories on to future generations, according to new research.
Ubiquitous bacteria, Escherichia coli, There is One of the most well-studied life forms On Earth, scientists are still discovering unexpected ways it survives and spreads.
Researchers at the University of Texas and the University of Delaware have now discovered a possible memory system. E – Coli To 'remember’ past experiences for hours and generations thereafter.
The team says that to their knowledge, this type of bacterial memory has not been discovered before.
Obviously, the memory that scientists discuss in this matter is not the same as conscious human memory.
Instead the phenomenon of bacterial memory describes How information from past experiences influences current decision making.
„Bacteria don’t have brains, but they can gather information from their environment, and if they encounter that environment frequently, they can store that information and quickly access it later for their benefit.” Explains The lead researcher from UT is molecular biologist Sauvik Bhattacharya.
Bhattacharya and his team’s findings are based on robust correlations of more than 10,000 bacterial 'aggregation’ assays.
These tests test that E – Coli Cells in the same plate cluster together as a migratory mass that moves with a single motor. Such behavior usually indicates that the cells combine to effectively search for a suitable environment.
On the other hand, when E – Coli Cells stick together in a sticky biofilm, which is their way of colonizing a nutrient surface.
In initial experiments, researchers exposed E – Coli cells to various environmental factors to see which conditions induced the fastest proliferation.
Ultimately, the team found that intracellular iron was a strong predictor of whether bacteria moved or stayed.
Low levels of iron were associated with faster and more efficient accumulation, whereas higher levels led to a more stable lifestyle.
Among the first generation E – Coli Cells, it seemed, were an instinctive response. But after experiencing just one swarming event, cells that experienced low iron levels later in life were faster and more efficient than before.
Furthermore, this 'iron’ memory is passed on to at least four generations of daughter cells, which form when the mother cell divides into two new cells.
By the seventh generation of daughter cells, that iron memory was naturally lost—and scientists could regain it if they artificially reinforced it.
The authors behind the study have yet to identify a potential memory system or a molecular mechanism behind its inheritance, but the strong correlation between intracellular iron and interstitial swarming behavior suggests that there is a continuous conditioning level at play.
Epigenetics also plays a role ’Memory’ transcends biological systems Through the generations E – Coli By regulating the 'on’ and 'off’ settings of specific genes, the researchers believe that the short period of inheritance is not the primary mechanism here.
Iron has been linked to many stress responses in bacteria. An intermediate memory system makes a lot of evolutionary sense to build around.
An iron-based memory system may help E – Coli Adaptation to adverse environmental conditions or antibiotics.
A single E – Coli can go Doubles in half an hourThus the ability to pass such a memory to daughter cells is beneficial even in slowly changing environments.
„Before oxygen existed in Earth’s atmosphere, early cellular life used iron for many cellular processes.” He says Bhattacharya.
„Iron was important not only in the origin of life on Earth, but also in the evolution of life. It makes sense that cells use it in this way.”
„Finally,” Bhattacharya concludes, „The more we know about bacterial behavior, the easier it is to fight them.”
The study was published in PNAS.