Lenski\'s E. Coli mutation rates show two types (Introduction)

by David Turell , Sunday, March 20, 2011, 02:08 (4998 days ago)

Fascinating study of Lenski's E. Coli. EW's are winners (more mutations) and EL's, losertfs, (less mutations). -http://www.the-scientist.com/news/display/58057/#ixzz1H33CKeSO-This fellow, who knows the study disagrees with the conclusions, and thinks the EW's are the losers!-"Andrew J. Fabich at Tennessee Temple University, who knows somewhat of bacteria, writes to say that none of the stuff about them is any big surprise,
Having read the paper, I'm impressed at the magnitude of the research, but not the conclusions. Wood et al. identified a spoT mutation in E. coli as what made his "Eventually Wins" (EW) strains less fit for competition. That's a no-brainer as spoT mutations studied as much as possible in an isolated background (that of a relA mutant) are always sick. I am not surprised that they identified a gene that made the strain weaker, despite its earlier chances for success. I have passaged an E. coli relA mutant through a mouse intestine and, even though it could colonize on its own, was far inferior to the wild-type in direct competition. Whenever you mess with the translation machinery and, specifically, the stringent response, you're setting yourself up for failure. It would've been more interesting to see a proper control experiment done in which the spoT mutation was introduced at the beginning of the long-term evolution experiment rather than identified at the very end. This has philosophical implications that Lenski thinks evolution has a goal in mind (i.e., spoT) rather than being random and without a goal."-Only Lenski knows what he thinks!