Ploidy and gene conversion in Archaea.

  title={Ploidy and gene conversion in Archaea.},
  author={J{\"o}rg Soppa},
  journal={Biochemical Society transactions},
  volume={39 1},
  • J. Soppa
  • Published 1 February 2011
  • Biology
  • Biochemical Society transactions
The genome copy numbers of seven crenarchaeal species of four genera have been reported. All of them are monoploid and thus this seems to be a characteristic feature of Crenarchaeota. In stark contrast, none of six species representing six euryarchaeal genera is monoploid. Therefore Euryarchaea are typically oligoploid or polyploidy and their genome copy numbers are tightly regulated in response to growth phase and/or growth rate. A theoretical consideration called 'Muller's ratchet' predicts… 

Figures and Tables from this paper

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.

Polyploidy in haloarchaea: advantages for growth and survival

The investigated haloarchaeal species, Halobacterium salinarum, Haloferax mediterranei, and H. volcanii, have all been shown to be polyploid, and stable storage of phosphate is proposed as an alternative driving force for the emergence of DNA in early evolution.

Evolutionary consequences of polyploidy in prokaryotes and the origin of mitosis and meiosis

Emergence of mitosis and the first evolutionary steps towards eukaryotic sex could have taken place in the ancestral polyploid, amitotic proto-eukaryotes, as they were struggling to survive in the highly mutagenic environment of the Early Proterozoic shallow water microbial communities.

Regulated ploidy of Bacillus subtilis and three new isolates of Bacillus and Paenibacillus

Results indicate that mero‐oligoploidy as well as growth phase‐dependent copy number regulation might be widespread in and typical for Bacillus and related genera.

Random Chromosome Partitioning in the Polyploid Bacterium Thermus thermophilus HB27

  • Haijuan Li
  • Medicine, Biology
    G3: Genes, Genomes, Genetics
  • 2019
It seems that protein-based chromosome segregation machineries are less critical for the polyploid T. thermophilus, and chromosome segregation in this bacterium are not stringently controlled but tend to be variable, and random segregation can occur.

Thermotogales origin scenario of eukaryogenesis.

The evolutionary significance of polyploidy

How, once polyploidy has been established, the unique retention profile of duplicated genes following whole-genome duplication might explain key longer-term evolutionary transitions and a general increase in biological complexity is discussed.

The Dynamic Nature of Genomes across the Tree of Life

It is hypothesized that dynamic genomes are a rule rather than the exception across the tree of life and that all domains may have the ability to distinguish germline from somatic DNA and that this ability may have been present the last universal common ancestor.

Evolutionary advantages of polyploidy in halophilic archaea.

  • J. Soppa
  • Biology
    Biochemical Society transactions
  • 2013
Nine different possible evolutionary advantages of polyploidy for haloarchaea are discussed, including low mutation rate, radiation/desiccation resistance, gene redundancy and survival over geological times and at extraterrestrial sites.

Random mutagenesis of the hyperthermophilic archaeon Pyrococcus furiosus using in vitro mariner transposition and natural transformation

Transposition mutagenesis is a powerful tool to identify the function of genes, reveal essential genes and generally to unravel the genetic basis of living organisms. However, transposon-mediated



Genome Copy Numbers and Gene Conversion in Methanogenic Archaea

It was shown that in the absence of selection very fast equalization of genomes in M. maripaludis took place probably via a gene conversion mechanism, and that the velocity of this phenomenon is inversely correlated to the strength of selection.

Regulated Polyploidy in Halophilic Archaea

The results indicate that polyploidy might be more widespread in archaea (or even prokaryotes in general) than previously assumed, and the presence of so many genome copies in a proKaryote raises questions about the evolutionary significance of this strategy.

Frequent Recombination in a Saltern Population of Halorubrum

Multi-locus sequence typing is used to demonstrate that haloarchaea exchange genetic information promiscuously, exhibiting a degree of linkage equilibrium approaching that of a sexual population.

Cell cycle characteristics of thermophilic archaea

The in vivo organization of the chromosome DNA appeared to be different from that of eubacteria, as revealed by variation in the relative binding efficiency of different DNA stains.

Development of Additional Selectable Markers for the Halophilic Archaeon Haloferax volcanii Based on the leuB and trpA Genes

ABSTRACT Since most archaea are extremophilic and difficult to cultivate, our current knowledge of their biology is confined largely to comparative genomics and biochemistry. Haloferax volcanii

Cell Cycle Characteristics of Crenarchaeota: Unity among Diversity

In Pyrobaculum, chromosome segregation overlapped with or closely followed DNA replication, and further genome separation appeared to occur concomitant with cellular growth, and cell division in P. aerophilum took place without visible constriction.

Nucleoid structure and partition in Methanococcus jannaschii: an archaeon with multiple copies of the chromosome.

During entry into stationary phase, chromosome replication continued to termination while no new rounds were initiated: the cells ended up with one to five chromosomes per cell with no apparent preference for any given DNA content.

Isolation of acetate auxotrophs of the methane-producing archaeon Methanococcus maripaludis by random insertional mutagenesis.

To learn more about autotrophic growth of methanococci, nine conditional mutants of Methanococcus maripaludis were isolated after transformation of the wild type with a random library in pMEB and insertion of pWDK104 into the genome was established.