Genetic architecture of thermal adaptation in Escherichia coli. Proc Natl Acad Sci U S A 2001 Jan 16;98(2):525-30
Date
01/10/2001Pubmed ID
11149947Pubmed Central ID
PMC14620DOI
10.1073/pnas.98.2.525Scopus ID
2-s2.0-0035895278 (requires institutional sign-in at Scopus site) 210 CitationsAbstract
Elucidating the genetic basis of adaptation on a genomewide scale has evaded biologists, but complete genome sequences and DNA high-density array technology make genomewide surveys more tractable. Six lines of Escherichia coli adapted for 2,000 generations to a stressful high temperature of 41.5 degrees C were examined on a genomewide scale for duplication/deletion events by using DNA high-density arrays. A total of five duplication and deletion events were detected. These five events occurred in three of the six lines, whereas the remaining three lines contained no detectable events. Three of the duplications were at 2.85 Mb of the E. coli chromosome, providing evidence for the replicability of the adaptation to high temperature. Four candidate genes previously shown to play roles in stress and starvation survival were identified in the region of common duplication. Expression of the two candidate genes examined is elevated over expression levels in the ancestral lines or the lines without the duplication. In the two cases where the duplication at 2.85 Mb has been further characterized, the timing of the genome reorganization is coincident with significant increases in relative fitness. In both of these cases, the model for the origin of the duplication is a complex recombination event involving insertion sequences and repeat sequences. These results provide additional evidence for the idea that gene duplication plays an integral role in adaptation, specifically as a means for gene amplification.
Author List
Riehle MM, Bennett AF, Long ADAuthor
Michelle M. Riehle PhD Assistant Professor in the Microbiology and Immunology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adaptation, PhysiologicalChromosomes, Bacterial
DNA, Bacterial
Escherichia coli
Evolution, Molecular
Gene Deletion
Gene Duplication
Gene Expression Regulation, Bacterial
Genes, Bacterial
Genome, Bacterial
Hot Temperature
Oligonucleotide Array Sequence Analysis
Open Reading Frames
Recombination, Genetic
Selection, Genetic