Polintons: a hotbed of eukaryotic virus, transposon and plasmid evolution

• Published in: Nature reviews. Microbiology Vol. 13; no. 2; pp. 105 - 115
• Main Authors: Krupovic, Mart, Koonin, Eugene V.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.02.2015; Nature Publishing Group
• Subjects: 631/326/596; 631/326/596/2554; Adenoviruses; Biological Evolution; Deoxyribonucleic acid; DNA; DNA Transposable Elements; DNA Transposable Elements - genetics; DNA viruses; DNA, Viral; DNA, Viral - genetics; Eukaryotes; Gene Expression Regulation, Viral; Gene Expression Regulation, Viral - physiology; Genetic aspects; Genetic research; Genome, Viral; Genomes; Infectious Diseases; Life Sciences; Medical Microbiology; Microbial genetics; Microbiology; Microbiology and Parasitology; Mitochondria; Models, Molecular; opinion-2; Parasitology; Phages; Plasmids; Plasmids - genetics; Properties; Protein Conformation; Transposons; Viral Proteins; Viral Proteins - genetics; Viral Proteins - metabolism; Virions; Virology; Viruses; Viruses - genetics
• ISSN: 1740-1526; 1740-1534; 1740-1534
• DOI: 10.1038/nrmicro3389

Polintons are large DNA transposons that are widespread in the genomes of eukaryotes. Here, Krupovic and Koonin propose that Polintons were the first group of eukaryotic double-stranded DNA viruses to evolve from bacteriophages and that they gave rise to most large DNA viruses of eukaryotes and various other selfish elements. Polintons (also known as Mavericks) are large DNA transposons that are widespread in the genomes of eukaryotes. We have recently shown that Polintons encode virus capsid proteins, which suggests that these transposons might form virions, at least under some conditions. In this Opinion article, we delineate the evolutionary relationships among bacterial tectiviruses, Polintons, adenoviruses, virophages, large and giant DNA viruses of eukaryotes of the proposed order 'Megavirales', and linear mitochondrial and cytoplasmic plasmids. We hypothesize that Polintons were the first group of eukaryotic double-stranded DNA viruses to evolve from bacteriophages and that they gave rise to most large DNA viruses of eukaryotes and various other selfish genetic elements.