No macro-evolution in microbes

[luke_루크]

Proc Natl Acad Sci U S A 2003 Feb 4;100(3):1072-7 Related Articles, Links

Parallel changes in gene expression‎ after 20,000 generations of evolution in Escherichiacoli.

Cooper TF, Rozen DE, Lenski RE.

Center for Microbial Ecology, Michigan State University, East Lansing, MI 48824, USA. cooperti@msu.edu

Twelve populations of Escherichia coli, derived from a common ancestor, evolved in a glucose-limited medium for 20,000 generations. Here we use DNA expression‎ arrays to examine whether gene-expression‎ profiles in two populations evolved in parallel, which would indicate adaptation, and to gain insight into the mechanisms underlying their adaptation. We compared the expression‎ profile of the ancestor to that of clones sampled from both populations after 20,000 generations. The expression‎ of 59 genes had changed significantly in both populations. Remarkably, all 59 were changed in the same direction relative to the ancestor. Many of these genes were members of the cAMP-cAMP receptor protein (CRP) and guanosine tetraphosphate (ppGpp) regulons. Sequencing of several genes controlling the effectors of these regulons found a nonsynonymous mutation in spoT in one population. Moving this mutation into the ancestral background showed that it increased fitness and produced many of the expression‎ changes manifest after 20,000 generations. The same mutation had no effect on fitness when introduced into the other evolved population, indicating that a mutation of similar effect was present already. Our study demonstrates the utility of expression‎ arrays for addressing evolutionary issues including the quantitative measurement of parallel evolution in independent lineages and the identification of beneficial mutations.

in humans

Payseur BA, Nachman MW. Related Articles, Links
Natural selection at linked sites in humans.
Gene. 2002 Oct 30;300(1-2):31-42.

bacteria again

Shaver AC, Dombrowski PG, Sweeney JY, Treis T, Zappala RM, Sniegowski PD. Related Articles, Links
Fitness evolution and the rise of mutator alleles in experimental Escherichia coli populations.
Genetics. 2002 Oct;162(2):557-66.

and fruit flies

Harr B, Kauer M, Schlotterer C. Related Articles, Links
Hitchhiking mapping: a population-based fine-mapping strategy for adaptive mutations in Drosophilamelanogaster.
Proc Natl Acad Sci U S A. 2002 Oct 1;99(20):12949-54.
PMID: 12351680 [PubMed - indexed for MEDLINE] Harr B, Kauer M, Schlotterer C. Related Articles, Links 
Hitchhiking mapping: a population-based fine-mapping strategy for adaptive mutations in Drosophilamelanogaster.
Proc Natl Acad Sci U S A. 2002 Oct 1;99(20):12949-54.
PMID: 12351680 [PubMed - indexed for MEDLINE]