Evolution of genome architecture in archaea: spontaneous generation of a new chromosome in Haloferax volcanii

Ausiannikava, Darya; Mitchell, Laura; Marriott, Hannah; Smith, Victoria; Hawkins, Michelle; Makarova, Kira S.; Koonin, Eugene V.; Nieduszynski, Conrad A.; Allers, Thorsten

Abstract

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.

Citation

Ausiannikava, D., Mitchell, L., Marriott, H., Smith, V., Hawkins, M., Makarova, K. S., Koonin, E. V., Nieduszynski, C. A., & Allers, T. (2018). Evolution of genome architecture in archaea: spontaneous generation of a new chromosome in Haloferax volcanii. Molecular Biology and Evolution, 35(8), 1855-1868. https://doi.org/10.1093/molbev/msy075

• Journal Article Type: Article
• Acceptance Date: Apr 13, 2018
• Online Publication Date: Apr 16, 2018
• Publication Date: Aug 1, 2018
• Deposit Date: Apr 17, 2018
• Publicly Available Date: Apr 17, 2018
• Journal: Molecular Biology and Evolution
• Print ISSN: 0737-4038
• Electronic ISSN: 1537-1719
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 35
• Issue: 8
• Pages: 1855-1868
• DOI: https://doi.org/10.1093/molbev/msy075
• Keywords: Chromosome, Genome architecture, Multipartite genome, Homologous recombination, Genome stability, Archaea, Haloferax volcanii
• Public URL: https://nottingham-repository.worktribe.com/output/948626
• Publisher URL: https://academic.oup.com/mbe/advance-article/doi/10.1093/molbev/msy075/4972485
• Contract Date: Apr 17, 2018