A single change in a bacterial cell could influence entire generations. How does such a small organism manage to preserve a lasting record of a passing event?
Bacterial biology is not limited to the information contained in DNA. Recent discoveries show that non-genetic memories can be passed on to offspring.
Credit: Camila Felix/Northwestern University
According to a study conducted by researchers at Northwestern and Texas-Southwestern universities, certain bacteria are able to remember temporary modifications and transmit them to their descendants. This phenomenon, although not modifying DNA, could open the way to revolutionary medical applications.
For researchers, these memories are stored in gene regulatory networks, internal circuits of communication between genes themselves. By temporarily disabling a embarrassed at the house of Escherichia colia well-known model, the team observed that this disruption could induce lasting changes, inherited over several generations.
These changes are comparable to echoes, transmitted from one gene to another, even after the initial gene is reactivated. This phenomenon, which the team calls a “self-sustaining network”, is resistant to external influences once it is triggered.
The study opens up fascinating prospects for the fight against antibiotic resistance. By subtly modifying pathogenic bacteria, we could make their descendants more sensitive to treatments, over several generations.
The researchers now plan to validate these results in the laboratory, using tools like CRISPR to temporarily disable certain genes. If the results are confirmed, they could transform our understanding of non-genetic inheritance in living organisms.
Finally, although this research focuses on E. coliother organisms may well share this ability to transmit non-genetic memories. If this phenomenon is confirmed, it could call into question many certainties in the field of biology.
What is a gene regulatory network?
A gene regulatory network is a complex system by which genes interact with each other to control gene expression. Unlike a fixed DNA sequence, this network is dynamic and can be modified by various environmental factors.
Genes do not function in isolation but form circuits where the activity of one gene can influence that of others, thus allowing fine and adaptive regulation of cellular functions.
How do temporary disruptions influence regulatory networks?
When temporary perturbations, such as silencing a gene, are introduced into a cell, they can cause changes in the gene regulatory network.
These changes are not simply reversible; they can trigger chain reactions that permanently alter the network. Once reactivated, the initial gene may have already initiated a regulatory process that persists, influencing future generations without directly altering the DNA.
This phenomenon helps us understand how non-genetic characteristics can be transmitted to offspring.
