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Driving Apart and Segregating Genomes in Archaea

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ABSTRACT

Genome segregation is a fundamental biological process in organisms from all domains of life. How this stage of the cell cycle unfolds in Eukarya has been clearly defined and considerable progress has been made to unravel chromosome partition in Bacteria. The picture is still elusive in Archaea. The lineages of this domain exhibit different cell-cycle lifestyles and wide-ranging chromosome copy numbers, fluctuating from 1 up to 55. This plurality of patterns suggests that a variety of mechanisms might underpin disentangling and delivery of DNA molecules to daughter cells. Here I describe recent developments in archaeal genome maintenance, including investigations of novel genome segregation machines that point to unforeseen bacterial and eukaryotic connections.

No MeSH data available.


Ploidy in a Set of Characterized Members of the Euryarchaea and Crenarchaea Phyla. All the euryarchaeal species (green box) contain multiple chromosome copies, whereas the crenarchaeal species (blue box) harbour a single chromosome.
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fig0005: Ploidy in a Set of Characterized Members of the Euryarchaea and Crenarchaea Phyla. All the euryarchaeal species (green box) contain multiple chromosome copies, whereas the crenarchaeal species (blue box) harbour a single chromosome.

Mentions: Analogous cell-cycle patterns and timing have been observed for all the Crenarchaea spp. studied to date which include Sulfolobus tokodaii, Acidianus hospitalis, Aeropyrum pernix, Pyrobaculum aerophilum, and Pyrobaculum calidifontis[11]. Although the number of crenarchaeal species characterized so far is limited, interestingly all are monoploid and harbour two chromosome copies only on completion of DNA replication (Figure 1). This observation suggests that an accurate and rigorous genome segregation mechanism must operate in these species to ensure the faithful distribution of chromosomes to daughter cells. Whereas chromosome segregation in bacteria occurs concomitantly with replication, the picture in Crenarchaea is very different: the two processes are temporally separated and genome segregation takes place only at the end of the protracted G2 stage 12, 13. The two Pyrobaculum spp. that have been examined represent a slight deviation from the canonical paradigm as chromosome segregation appears to be largely synchronized with replication [11].


Driving Apart and Segregating Genomes in Archaea
Ploidy in a Set of Characterized Members of the Euryarchaea and Crenarchaea Phyla. All the euryarchaeal species (green box) contain multiple chromosome copies, whereas the crenarchaeal species (blue box) harbour a single chromosome.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120986&req=5

fig0005: Ploidy in a Set of Characterized Members of the Euryarchaea and Crenarchaea Phyla. All the euryarchaeal species (green box) contain multiple chromosome copies, whereas the crenarchaeal species (blue box) harbour a single chromosome.
Mentions: Analogous cell-cycle patterns and timing have been observed for all the Crenarchaea spp. studied to date which include Sulfolobus tokodaii, Acidianus hospitalis, Aeropyrum pernix, Pyrobaculum aerophilum, and Pyrobaculum calidifontis[11]. Although the number of crenarchaeal species characterized so far is limited, interestingly all are monoploid and harbour two chromosome copies only on completion of DNA replication (Figure 1). This observation suggests that an accurate and rigorous genome segregation mechanism must operate in these species to ensure the faithful distribution of chromosomes to daughter cells. Whereas chromosome segregation in bacteria occurs concomitantly with replication, the picture in Crenarchaea is very different: the two processes are temporally separated and genome segregation takes place only at the end of the protracted G2 stage 12, 13. The two Pyrobaculum spp. that have been examined represent a slight deviation from the canonical paradigm as chromosome segregation appears to be largely synchronized with replication [11].

View Article: PubMed Central - PubMed

ABSTRACT

Genome segregation is a fundamental biological process in organisms from all domains of life. How this stage of the cell cycle unfolds in Eukarya has been clearly defined and considerable progress has been made to unravel chromosome partition in Bacteria. The picture is still elusive in Archaea. The lineages of this domain exhibit different cell-cycle lifestyles and wide-ranging chromosome copy numbers, fluctuating from 1 up to 55. This plurality of patterns suggests that a variety of mechanisms might underpin disentangling and delivery of DNA molecules to daughter cells. Here I describe recent developments in archaeal genome maintenance, including investigations of novel genome segregation machines that point to unforeseen bacterial and eukaryotic connections.

No MeSH data available.