Horizontal gene transfer and the evolution of transcriptionalregulation in Escherichia coli

Journal Article · Thu Dec 20 04:00:00 EST 2007 · Genome Biology

OSTI ID:932501

Price, Morgan N; Dehal, Paramvir S; Arkin, Adam P

Background: Most bacterial genes were acquired by horizontalgene transfer from other bacteria instead of being inherited bycontinuous vertical descent from an ancient ancestor}. To understand howthe regulation of these {acquired} genes evolved, we examined theevolutionary histories of transcription factors and of regulatoryinteractions from the model bacterium Escherichia coli K12. Results:Although most transcription factors have paralogs, these usually arose byhorizontal gene transfer rather than by duplication within the E. colilineage, as previously believed. In general, most neighbor regulators --regulators that are adjacent to genes that they regulate -- were acquiredby horizontal gene transfer, while most global regulators evolvedvertically within the gamma-Proteobacteria. Neighbor regulators wereoften acquired together with the adjacent operon that they regulate, sothe proximity might be maintained by repeated transfers (like "selfishoperons"). Many of the as-yet-uncharacterized (putative) regulators havealso been acquired together with adjacent genes, so we predict that theseare neighbor regulators as well. When we analyzed the histories ofregulatory interactions, we found that the evolution of regulation byduplication was rare, and surprisingly, many of the regulatoryinteractions that are shared between paralogs result from convergentevolution. Another surprise was that horizontally transferred genes aremore likely than other genes to be regulated by multiple regulators, andmost of this complex regulation probably evolved after the transfer.Conclusions: Our results highlight the rapid evolution of niche-specificgene regulation in bacteria.

• Research Organization: Ernest Orlando Lawrence BerkeleyNationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director. Office of Science. Biological andEnvironmental Research
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 932501
• Report Number(s): LBNL--63699; BnR: KP1501021
• Journal Information: Genome Biology, Journal Name: Genome Biology Vol. 9
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
ESCHERICHIA COLI
Evolutionary Biology Transcriptomics
GENE REGULATION
GENES
REGULATIONS
TRANSCRIPTION FACTORS