Research Shows Bacteria Take Advantage of Opportunities to Multiply

Recent study provides insight into the bacterial cell cycle, shows cell division and DNA replication are not independent.

A doctoral student has presented experimental data that show there are a minimum of 2 fail-safe points in the bacterial cell cycle that tie DNA replication to cell division. In nutrient-rich conditions, bacteria take advantage of the opportunity to multiply as quickly as possible.

Heidi A. Arjes, a doctoral student in the lab of Petra Levin, PhD, associate professor of biology in Arts & Sciences at Washington University in St. Louis, presented the evidence in the August 28, 2014, issue of Current Biology.

"When I talk to people who study eukaryotic cells about our work with the bacterial cell cycle, they say, 'What? This is new? People don't know this?'" said Arjes in a press release. "But when I talk to people who study bacterial cells, they're astonished. It's a completely novel idea."

Arjes’ work shows that cell division and DNA replication are not independent. One experiment showed that after the division process was blocked, DNA replication diminished over time. This is unusual, as it is a single-celled organism’s purpose in life to divide.

"It might actually be a form of altruism," Arjes said. "In nature, bacteria often exist not in isolation, but in communities. An aged or unhealthy cell that removed itself from the population would benefit the community as a whole because it would no longer compete for nutrients or produce defective daughter cells."

The mechanisms that ensure proper cell cycle progression are still a mystery to Arjes and her team of researchers.

"That's the next thing we have to do," Levin said. "Figure out how the division machinery is telling the DNA replication machinery something is wrong [and how the] information that DNA replication isn't working is communicated to the division machinery."