Sep 5, 2023
“…Will it surprise you to learn that not every bacterium is a team player?”
(I am indebted to Holly Barker, Ph.D., and Mariella Bodemeier Loayza Careaga, Ph.D., for these insights into the science of bacteriology and to my grandfather, J. Leo Foley, for my appreciation of the art of football.)
As children, we waited impatiently for the ‘major holidays’, Halloween and Christmas, and somewhat more patiently for ‘minor holidays’ like Thanksgiving and the 4th of July. As adults, our priorities have changed: now we join the rest of America in counting down the hours to the beginning of another NFL/NCAA football season.
But what on earth does bacteriology have to do with football? A lot, as it turns out, and I’m not talking about COVID-19 infections. Turns out, an understanding of football can enhance our appreciation of cellular processes…and vice versa.
In contrast to the bacteria that we (and by ‘we’ I mean ‘you’) study in the lab, most prokaryotes (cells without nuclei) in nature live in complex communities, often consisting of several interacting, cooperating species. Within these communities, different bacteria assume different responsibilities.
Some individuals focus on reproduction to expand the colony, while others specialize in construction, oozing proteins that make up the extracellular superstructure. Yet other bacteria defend the community, building and shooting molecular weapons (toxins) at competitors.
What makes this interesting, and important, is that these secondary functions are not hard-wired. Like Shakespeare’s players, ‘one cell in its time plays many parts’. As the needs of the community change, an individual bacterium may take on new responsibilities.
In populations of Bacillus subtilis, for example, young microbes are responsible for the production of the colony’s extracellular superstructure, but as that construction progresses, some cells switch to producing spores or enzymes.
So how do bacterial colonies coordinate this division of labor? Most likely, they don’t! Then how does it happen? Perhaps individual bacteria simply amplify random fluctuations in cellular chemistry, resulting in auto-specialization. Inefficient, but possible.
More likely, cells may react to perceived stresses in the colony, taking it upon themselves to fill the gaps. In no case, however, is it likely that the morphing of cell function is due to the cell’s structure ‘at birth’ or to direction from some central or hierarchical ‘authority’.
Football commentary places a lot of emphasis on game plan (i.e., the X’s and O’s, the plays as designed). This is the functional equivalent of the bacterium’s DNA. But does strategy (alone) win football games? Of course not, execution is key, and execution comes in two flavors:
How well does the team execute its designed plays?
How well does the team execute plays that are not designed, i.e. the plays that happen once the designed plays fall apart in the fog…in other words, all plays?
Researchers have known for more than 20 years that bacteria differentiate in order to enable complex social behaviors that benefit the colony as a whole. But will it surprise you to learn that not every bacterium is a team player? Hmm.
While members of the colony generally ‘realize’ that the overall health of the colony broadly benefits its members, it is also the case that some players seek to enhance their individual well-being by free riding. Sound familiar? Instead of producing (secreting) socially valuable molecules, these cells assume the role of consumers, reaping where they did not sow, taking advantage of the insight and labor of their eleemosynary cousins.
So how is a football team like a colony of bacteria? First, each player is assigned a ‘position’ and that position includes a specific set of behaviors which become that player’s primary responsibility. But as with bacterial colonies, this is only the beginning.
As each play unfolds, novel stresses arise which must be addressed if the team is going to meet its goals (e.g., score points). After fulfilling their prime directive, each player must react ‘to circumstances on the ground’: What secondary function can I perform that will increase the play’s likelihood of success?
My pass route’s a bust; can I still get open?
I knocked down one defender: why not two?
I’m supposed to run over Center, but the front’s a brick wall; should I run to daylight?
I missed one tackle; but can I still catch up to the action and try again?
And the free riders? These are the guys who ‘do their jobs’…who just do their jobs. They will throw themselves full force into a pig pile…once the ball carrier is safely down…or push a retreating runner out of bounds.
So long as the free riders are relatively few, and team relatively successful, these malcontents are likely to get away with their shenanigans. But once free riding proliferates, or the team starts to lose, as it will, watch out!
Since Genesis, we humans have shamefully sought to distance ourselves from ‘lower’ life forms; you know, plants, other animal species, people from other tribes, races, nations…the usual suspects. But the last 50 years have made it crystal clear that this strategy is a bust! It is as impractical as it is immoral.
We need a new, more inclusive, bio-ethics, and I suggest that we begin our investigations with a new guiding principle: “Bacteria…and football players…are people too!”