Frequent Recombination in a Saltern Population of Halorubrum

  title={Frequent Recombination in a Saltern Population of Halorubrum},
  author={R Thane Papke and Jeremy E. Koenig and Francisco Rodr{\'i}guez-Valera and W. Ford Doolittle},
  pages={1928 - 1929}
Sex and recombination are driving forces in the evolution of eukaryotes. Homologous recombination is known to be the dominant process in the divergence of many bacterial species. For Archaea, the only direct evidence bearing on the importance or natural occurrence of homologous recombination is anecdotal reports of mosaicism from comparative genomic studies. Genetic studies, however, reveal that recombination may play a significant role in generating diversity among members of at least one… 
Recombination shapes the natural population structure of the hyperthermophilic archaeon Sulfolobus islandicus.
It is proposed that frequent recombination among closely related individuals prevents periodic selection from purging diversity and provides a fundamental cohesive mechanism within this and perhaps other archaeal species.
A comparison of homologous recombination rates in bacteria and archaea
Multi Locus Sequence Typing datasets from a wide variety of bacteria and archaea are analyzed using the ClonalFrame method, enabling a direct comparison between species and allowing for a first exploration of the question whether phylogeny or ecology is the primary determinant of homologous recombination rate.
Horizontal Gene Transfer, Dispersal and Haloarchaeal Speciation
It is suggested that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria.
Differences in homologous recombination and maintenance of heteropolyploidy between Haloferax volcanii and Haloferax mediterranei
It is suggested that H. volcanii escapes Muller’s ratchet by means of an effective chromosome-equalizing gene-conversion mechanism facilitated by highly active homologous recombination, whereas H. mediterranei must elude the ratchet via a different, yet to be elucidated mechanism.
Recombination Does Not Hinder Formation or Detection of Ecological Species of Synechococcus Inhabiting a Hot Spring Cyanobacterial Mat
It is concluded that sexual isolation is more likely to follow ecological divergence than to precede it, and an ecology-based model of speciation appears more appropriate than the biological species concept for bacterial and archaeal diversification.
Population and genomic analysis of the genus Halorubrum
It is concluded that barriers to gene exchange exist between the two purely Aran-Bidgol phylogroups, and that the third cluster with members from other regions is not a single population and likely reflects an amalgamation of several populations.
Gene Transfer Mechanisms, Population Genetics/Genomics and the Evolution of Haloarchaea
Evidence indicating the evolutionary history of haloarchaea is riddled with gene transfer events and homologous recombination is presented, and the impact of LGT on the evolution of this halophilic group is discussed.
Mechanisms of gene flow in archaea
The current knowledge of archaeal mechanisms of DNA transfer is discussed, and the role of gene transfer in Archaeal evolution is highlighted.
Quantifying Homologous Replacement of Loci between Haloarchaeal Species
These findings are unexpected, because the transfer and homologous recombination of relaxed core genes between members of the class Halobacteria disrupts the coevolution of genes; however, the generation of new combinations of divergent but functionally related genes may lead to adaptive phenotypes not available through cumulative mutations and recombination within a single population.


Characterization of Intragenic Recombination in a Hyperthermophilic Archaeon via Conjugational DNA Exchange
Crosses among spontaneous pyr mutants were able to resolve closely spaced chromosomal mutations, identify deletions and rearrangements, and map mutations to a given deletion interval.
Recombination and the population structures of bacterial pathogens.
In many bacterial species, including Neisseria meningitidis, Streptococcus pneumoniae, and Staphylococcus aureus, evolutionary change at neutral (housekeeping) loci is more likely to occur by recombination than mutation and can result in the elimination of any deep-rooted phylogenetic signal.
The mechanism of DNA transfer in the mating system of an archaebacterium.
The mechanism of genetic transfer of this archaebacterium was studied by using the immobile plasmids pHV2 and pHV11 as cytoplasmic markers and found that the cytoplasms of the parental types do not mix during the mating process, and that each parental type can serve both as a donor and as a recipient.
Haloarchaeal viruses: how diverse are they?
The relative contributions of recombination and mutation to the divergence of clones of Neisseria meningitidis.
Analysis of an MLST data set consisting of the sequences of approximately 450-bp fragments from seven housekeeping loci from a large strain collection of Neisseria meningitidis revealed that a single nucleotide site in a meningococcal housekeeping gene is at least 80-fold more likely to change as a result of recombination than as a results of mutation.
Conjugation in archaea: frequent occurrence of conjugative plasmids in Sulfolobus.
We describe five novel conjugative plasmids (CPs) and two subfamilies, each comprising several closely related variants of CPs isolated from colony-cloned strains of the extremely thermophilic,
Genetic diversity and structure in Escherichia coli populations.
A survey of electrophoretic variation in 20 enzymes from 109 clones of escherichia coli from natural populations yielded an estimate of mean genetic diversity approximately twice that reported in an
Intragenomic Heterogeneity and Intergenomic Recombination among Haloarchaeal rRNA Genes
It is suggested that intragenomic heterogeneity of rRNA operons is an ancient and stable trait in several lineages of the Halobacteriales.
Prokaryotic genetic diversity throughout the salinity gradient of a coastal solar saltern.
Water samples from eight ponds were analysed, covering a salinity range from near sea water to saturated sodium chloride, and both Bacteria and Archaea showed the same pattern; as salinity increased, the number of different clusters decreased, and only one cluster became dominant.
How clonal are bacteria?
Data from multilocus enzyme electrophoresis of bacterial populations were analyzed using a statistical test designed to detect associations between genes at different loci, and found panmictic, epidemic, and clonal population structures.