An intriguing paper titled Emergent Properties of Reduced-Genome Escherichia coli was published this week in Science. Posfai et al literally trimmed E. coli K-12, they removed all the non-functional genes and some of those that were host-specific. This led to the creation of several new strains with about 20% less “genomic content”.
The selected reduced strains grew and functioned comparably to the parent ones, some other unexpected features appeared. For instance, this new strains have higher electroporation efficiency. Also they had an increase in the propagation of recombinant genes and plasmids that were unstable in other strains.
I think that this might be taken superficially as yet another thing to do with a bacterium, but what I find very suggestive is the fact that bacteria that lacked of mobile genetics elements tended to take them easier from the environment, as if there was a need to carry them or something. This strenghtens the theory of transposons as a machinery for self-mutation in extreme cases, which itself reinforces the fact that the genome is anything but static. Is an interacting entity capable of modifying itlsef.