Evolution of Genome Architecture in Archaea: Spontaneous Generation of a New Chromosome in Haloferax volcanii

TY - JOUR

T1 - Evolution of Genome Architecture in Archaea

T2 - Spontaneous Generation of a New Chromosome in Haloferax volcanii

AU - Ausiannikava, Darya

AU - Mitchell, Laura

AU - Marriott, Hannah

AU - Smith, Victoria

AU - Hawkins, Michelle

AU - Makarova, Kira S

AU - Koonin, Eugene V.

AU - Nieduszynski, Conrad A

AU - Allers, Thorsten

N1 - © The Author(s) 2018.

PY - 2018/8

Y1 - 2018/8

N2 - The common ancestry of archaea and eukaryotes is evident in their genome architecture. All eukaryotic and several archaeal genomes consist of multiple chromosomes, each replicated from multiple origins. Three scenarios have been proposed for the evolution of this genome architecture: (1) mutational diversification of a multi-copy chromosome; (2) capture of a new chromosome by horizontal transfer; (3) acquisition of new origins and splitting into two replication-competent chromosomes. We report an example of the third scenario: the multi-origin chromosome of the archaeon Haloferax volcanii has split into two elements via homologous recombination. The newly-generated elements are bona fide chromosomes, because each bears 'chromosomal' replication origins, rRNA loci and essential genes. The new chromosomes were stable during routine growth but additional genetic manipulation, which involves selective bottlenecks, provoked further rearrangements. To the best of our knowledge, rearrangement of a naturally-evolved prokaryotic genome to generate two new chromosomes has not been described previously.

AB - The common ancestry of archaea and eukaryotes is evident in their genome architecture. All eukaryotic and several archaeal genomes consist of multiple chromosomes, each replicated from multiple origins. Three scenarios have been proposed for the evolution of this genome architecture: (1) mutational diversification of a multi-copy chromosome; (2) capture of a new chromosome by horizontal transfer; (3) acquisition of new origins and splitting into two replication-competent chromosomes. We report an example of the third scenario: the multi-origin chromosome of the archaeon Haloferax volcanii has split into two elements via homologous recombination. The newly-generated elements are bona fide chromosomes, because each bears 'chromosomal' replication origins, rRNA loci and essential genes. The new chromosomes were stable during routine growth but additional genetic manipulation, which involves selective bottlenecks, provoked further rearrangements. To the best of our knowledge, rearrangement of a naturally-evolved prokaryotic genome to generate two new chromosomes has not been described previously.

KW - Journal Article

KW - Genome stability

KW - Haloferax volcanii

KW - Multipartite genome

KW - Archaea

KW - Homologous recombination

KW - Chromosome

KW - Genome architecture

KW - Genome, Archaeal

KW - Biological Evolution

KW - Chromosomes, Archaeal

KW - Haloferax volcanii/genetics

KW - Replicon

UR - http://www.scopus.com/inward/record.url?scp=85054931837&partnerID=8YFLogxK

U2 - 10.1093/molbev/msy075

DO - 10.1093/molbev/msy075

M3 - Article

C2 - 29668953

SN - 0737-4038

VL - 35

SP - 1855

EP - 1868

JO - Molecular Biology and Evolution

JF - Molecular Biology and Evolution

IS - 8

ER -