Researchers have found that genetically identical bacteria can behave in radically different ways, depending on how the cells divide. What’s more, the researchers suspect that human cells might act in a similar manner. This could have profound implications for the development of antibiotics and other drugs. The results come from lead author Bridget Kulasekara from the University of Washington and was published in the journal eLife.
When learning about how one cell splits into two daughter cells, it is most often in a perfect-case scenario as everything is split completely evenly. However, we know this isn’t the case and cellular organelles aren’t divided as evenly as textbook diagrams would lead you to believe. How these organelles are divvied up during mitosis will determine future behavior. This interjects a little diversity into a population of cells that may be genetically identical, allowing them to react differently when obstacles arise, such as scarce resources or a dose of antibiotics.
This research builds on results from 2010, when the team showed that cyclic diguanosine monophosphate (cyclic di-GMP), a second messenger molecule used for signal transduction in prokaryotes, is not distributed evenly when daughter cells split. Cyclic di-GMP regulates many processes in the cell, including metabolism. It also nearly instantaneously regulates how the bacterial cell moves, either toward food or away from danger. Because some cells have more cyclic di-GMP than others, some cells are uniquely poised to gather resources or avert toxins.
Although the cells that are lacking certain structures can make their own, those who receive everything they need right off the bat have an immediate advantage as they do not have to dedicate the time or resources into coding for it. However, more cyclic diGMP isn’t always better, as too much can leave bacteria moving without much control. The propeller (such as flagella or pilli) which allows the bacteria to move often also comes with an enzyme to reduce cyclic di-GMP, allowing the cell to move in a more controlled manner. Whether this enzyme is active earlier or later has profound effects on how the bacterial cell interacts with the environment.
Understanding how bacteria diversify is critically important, as we face increasing amounts of antibiotic resistance. Antibiotics work much better on the faster cells with increased amounts of cyclic di-GMP, giving those with lower amounts a better chance at escaping the drug and developing a resistance. Future research from this lab will seek to exploit the second message system in order to combat resistance and improve antibiotic efficacy.