Genetic circuits in some bacteria help them survive in variable environments by introducing genetic diversity into the population.

“Like savvy Wall Street money managers, bacteria hedge their bets to
increase their chances of survival in uncertain times, strategically
investing their biological resources to weather unpredictable
environments.

UT Southwestern Medical Center researchers describe how bacteria play
the market so well. Inside each bacterial cell are so-called genetic
circuits that provide specific survival skills. Within the bacteria
population, these genetic circuits generate so much diversity that the
population as a whole is more tolerant of — and is more likely to
survive — a wide range of variability in the environment

“This diversity, like a diversified investment portfolio, means that each
bacterium has characteristics that allow it to survive under certain
conditions, said Dr. Süel. ‘When conditions are highly variable, some
individual bacteria are equipped to thrive in the highs or lows, while
others tank,’ he said

“By generating diversity, genetic circuits ensure enough cells will
survive to carry over the population, especially in times of variable
conditions, Dr. Süel explained. Essentially, variability of bacterial
cells appears to match the variability in the environment, thereby
increasing the chances of bacterial survival, he said.

“Biological ‘noise’ in the genetic circuit, which comes from random
fluctuations in the chemical reactions involved in the pattern of
interactionsis beneficial. In fact, it is the root
mechanism that drives diversity within the bacteria population. Dr. Süel
previously found that when noise reaches a certain level in some
genetic circuits, it can prompt cells to transform from one cellular
state to another.”(Science Daily 2009)

http://www.cell.com/retrieve/pii/S0092867409010332
http://www.sciencedaily.com/releases/2009/11/091102112102.htm

Last Updated August 18, 2016