A new study conducted jointly by Northwestern University and the University of Texas Southwestern has found that bacterial cells can "remember" temporary changes in their body and surrounding environment. Although these changes are not encoded in the cell's genetic code, the cell still passes on the memory of these changes to offspring and persists for multiple generations. The study was published in the latest issue of the journal Science Advances. This discovery challenges long-standing assumptions about how the simplest organisms transmit and inherit bodily features. Using new discoveries, researchers can cleverly adjust pathogens to make their offspring more sensitive to treatment, thereby avoiding antibiotic resistance. A central assumption in bacterial biology is that heritable physical characteristics are primarily determined by DNA. However, from the perspective of complex systems, information can also be stored at the level of regulatory networks between genes. New research explores whether there are features transmitted from parents to offspring that are not encoded in DNA, but in the regulatory network itself. It was found that temporary changes in gene regulation would leave lasting effects within the network, which would be transmitted to future generations. In other words, memories that affect changes in their parents persist in the regulatory network, while DNA remains unchanged. The research team used a mathematical model of regulatory networks to simulate the temporary inactivation and subsequent reactivation of individual genes in Escherichia coli. They found that these transient disturbances produce persistent changes, which are expected to be inherited for several generations. The team is currently using CRISPR variants in the laboratory to validate their simulations, which can temporarily, rather than permanently, inactivate genes. The research team hypothesizes that reversible disturbances trigger irreversible chain reactions within the regulatory network. When a gene is inactivated, it affects the surrounding genes in the network. When inactive genes are reactivated, the cascade reaction will once again be in full swing because genes can form self-sustaining circuits that, once activated, are not affected by external factors. (New Society)