Virology 466-467 (2014) 1–2
Contents lists available at ScienceDirect
Virology journal homepage: www.elsevier.com/locate/yviro
Editorial introduction to “Giant Viruses” special issue of Virology Viruses are usually perceived as highly streamlined parasites, encoding the bare minimum of information required for reproduction. Although complex viruses with more than one hundred genes, such as Baculo-, Herpes- and Poxviruses, have been known for decades, it was only in recent years that large DNA viruses have attracted a wider attention. In particular, it was the serendipitous discovery of Acanthamoeba polyphaga mimivirus, the first virus shown to harbor a megabase pair-sized genome (Raoult et al., 2004), that extended the viral spectrum far into the realm of cellular life and stimulated an intense debate about the nature of viruses and their evolutionary significance. Since then, a targeted search for giant viruses has unsheathed a staggering variety of viruses with ostentatiously large genome and particle sizes, and many more are awaiting discovery.
Although there is no clear definition for what constitutes a “giant virus”, it is commonly agreed upon that these are dsDNA viruses with genome sizes beyond 200 kilobase pairs, and particles that do not pass through a 0.2 mm pore-size filter (which is routinely used to separate viral from cellular life forms). The current record holders of this rapidly growing group are Pandoravirus salinus with a 2.5 Mbp genome (Philippe et al., 2013) and Pithovirus sibericum with a particle size of 1.5 0.5 mm (Legendre et al., 2014). The majority of giant DNA viruses infect unicellular eukaryotes and belong to the group of Nucleo-Cytoplasmic Large DNA Viruses (NCLDV), which comprises the viral families Ascoviridae, Asfarviridae, Iridoviridae, Marseilleviridae, Mimiviridae, Phycodnaviridae, and Poxviridae. Based on their apparent monophyletic origin, the viral order Megavirales was recently proposed
Fig. 1. Participants of the 1st International Symposium on Giant Virus Biology (from left to right): Michael Rossmann, Grieg Steward, Vincent Racaniello, Antonis Chatzinotas, Jean-Michel Claverie, Stewart Shuman, Chantal Abergel, Bernard La Scola, Mathieu Legendre, Philippe Colson, Hiroyuki Ogata, Modesto Redrejo-Rodríguez, Ilme Schlichting, Anna Moroni, Jonathan Filée, Linda Müller, Jason Mercer, Dennis Bamford, Gerhard Thiel, Eugene Koonin, Barbara Müller, Mart Krupovic, Matthias Fischer, Jacomine KrijnseLocker, Asaaf Vardi, Sheree Yau, Abraham Minsky, Corina Brussaard, Chuan Xiao, Kiran Kondagabil, Geraldine Van Etten, James Van Etten, Andrei Lupas, Curtis Suttle, RuthAnne Sandaa, Rudolf Amann, Declan Schroeder, William Wilson, Steven Wilhelm.
http://dx.doi.org/10.1016/j.virol.2014.07.047 0042-6822/& 2014 Elsevier Inc. All rights reserved.
2
Editorial / Virology 466-467 (2014) 1–2
to replace the NCLDV as an official taxonomic unit (Colson et al., 2013). Giant viruses replicate partially or entirely in the host cytoplasm and code for an enzymatic variety that is unrivaled in the virus world. They are largely independent from their eukaryotic hosts in terms of DNA replication and repair, transcription, glycosylation, and other processes yet to be studied in greater detail. Such complexity, in turn, attracts parasites like virophages, a class of satellite-like dsDNA viruses that depend on giant viruses of the Mimiviridae family (La Scola et al., 2008). Ten years after Mimivirus was introduced to the public, 39 scientists from 14 countries gathered at Max Planck Society's Ringberg Castle, located south of Munich, for the 1st International Symposium on Giant Virus Biology (Fig. 1). The 25 presentations covered a wide range of topics, from biochemistry to genomics, from virus structure and assembly to ecological and evolutionary questions. This holistic approach to the biology of giant viruses allowed for inspiring discussions and a fruitful exchange of ideas, and resulted in the unanimous call for a follow-up meeting in 2015. In this special issue of Virology, we highlight some of the stories that were presented during the 2013 Ringberg Symposium. We are grateful to the authors for the time and effort they put into their contributions and to Elsevier for making all papers in this special issue open access. Although the field of giant virus research is still a young one, it has already achieved a remarkable feat by changing the way we think about viruses, and we eagerly await future developments.
La Scola, B., Desnues, C., Pagnier, I., Robert, C., Barrassi, L., Fournous, G., Raoult, D., 2008. The virophage as a unique parasite of the giant mimivirus. Nature 455 (7209), 100–104. http://dx.doi.org/10.1038/nature07218. Legendre, M., Bartoli, J., Shmakova, L., Jeudy, S., Labadie, K., Adrait, A., Claverie, J.-M, 2014. Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology. Proc. Natl. Acad. Sci. USA. , http: //dx.doi.org/10.1073/pnas.1320670111. Philippe, N., Legendre, M., Doutre, G., Coute, Y., Poirot, O., Lescot, M., Abergel, C., 2013. Pandoraviruses: amoeba viruses with genomes Up to 2.5 Mb reaching that of parasitic eukaryotes. Science 341 (6143), 281–286. http://dx.doi.org/ 10.1126/science.1239181. Raoult, D., Audic, S., Robert, C., Abergel, C., Renesto, P., Ogata, H., Claverie, J.-M., 2004. The 1.2-megabase genome sequence of Mimivirus. Science 306 (5700), 1344–1350. http://dx.doi.org/10.1126/science.1101485.
Editor Matthias G. Fischer n Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany E-mail address: mfi[email protected]
Editor Richard C. Condit University of Florida, P.O. Box 100266, Gainesville, FL 32610, USA E-mail address: condit@ufl.edu
Available online 28 August 2014
References Colson, P., De Lamballerie, X., Yutin, N., Asgari, S., Bigot, Y., Bideshi, D.K., Raoult, D., 2013. “Megavirales”, a proposed new order for eukaryotic nucleocytoplasmic large DNA viruses. Arch. Virol. 158 (12), 2517–2521. http://dx.doi.org/10.1007/ s00705-013-1768-6.
n
Corresponding author.
Contents lists available at ScienceDirect
Virology journal homepage: www.elsevier.com/locate/yviro
Editorial introduction to “Giant Viruses” special issue of Virology Viruses are usually perceived as highly streamlined parasites, encoding the bare minimum of information required for reproduction. Although complex viruses with more than one hundred genes, such as Baculo-, Herpes- and Poxviruses, have been known for decades, it was only in recent years that large DNA viruses have attracted a wider attention. In particular, it was the serendipitous discovery of Acanthamoeba polyphaga mimivirus, the first virus shown to harbor a megabase pair-sized genome (Raoult et al., 2004), that extended the viral spectrum far into the realm of cellular life and stimulated an intense debate about the nature of viruses and their evolutionary significance. Since then, a targeted search for giant viruses has unsheathed a staggering variety of viruses with ostentatiously large genome and particle sizes, and many more are awaiting discovery.
Although there is no clear definition for what constitutes a “giant virus”, it is commonly agreed upon that these are dsDNA viruses with genome sizes beyond 200 kilobase pairs, and particles that do not pass through a 0.2 mm pore-size filter (which is routinely used to separate viral from cellular life forms). The current record holders of this rapidly growing group are Pandoravirus salinus with a 2.5 Mbp genome (Philippe et al., 2013) and Pithovirus sibericum with a particle size of 1.5 0.5 mm (Legendre et al., 2014). The majority of giant DNA viruses infect unicellular eukaryotes and belong to the group of Nucleo-Cytoplasmic Large DNA Viruses (NCLDV), which comprises the viral families Ascoviridae, Asfarviridae, Iridoviridae, Marseilleviridae, Mimiviridae, Phycodnaviridae, and Poxviridae. Based on their apparent monophyletic origin, the viral order Megavirales was recently proposed
Fig. 1. Participants of the 1st International Symposium on Giant Virus Biology (from left to right): Michael Rossmann, Grieg Steward, Vincent Racaniello, Antonis Chatzinotas, Jean-Michel Claverie, Stewart Shuman, Chantal Abergel, Bernard La Scola, Mathieu Legendre, Philippe Colson, Hiroyuki Ogata, Modesto Redrejo-Rodríguez, Ilme Schlichting, Anna Moroni, Jonathan Filée, Linda Müller, Jason Mercer, Dennis Bamford, Gerhard Thiel, Eugene Koonin, Barbara Müller, Mart Krupovic, Matthias Fischer, Jacomine KrijnseLocker, Asaaf Vardi, Sheree Yau, Abraham Minsky, Corina Brussaard, Chuan Xiao, Kiran Kondagabil, Geraldine Van Etten, James Van Etten, Andrei Lupas, Curtis Suttle, RuthAnne Sandaa, Rudolf Amann, Declan Schroeder, William Wilson, Steven Wilhelm.
http://dx.doi.org/10.1016/j.virol.2014.07.047 0042-6822/& 2014 Elsevier Inc. All rights reserved.
2
Editorial / Virology 466-467 (2014) 1–2
to replace the NCLDV as an official taxonomic unit (Colson et al., 2013). Giant viruses replicate partially or entirely in the host cytoplasm and code for an enzymatic variety that is unrivaled in the virus world. They are largely independent from their eukaryotic hosts in terms of DNA replication and repair, transcription, glycosylation, and other processes yet to be studied in greater detail. Such complexity, in turn, attracts parasites like virophages, a class of satellite-like dsDNA viruses that depend on giant viruses of the Mimiviridae family (La Scola et al., 2008). Ten years after Mimivirus was introduced to the public, 39 scientists from 14 countries gathered at Max Planck Society's Ringberg Castle, located south of Munich, for the 1st International Symposium on Giant Virus Biology (Fig. 1). The 25 presentations covered a wide range of topics, from biochemistry to genomics, from virus structure and assembly to ecological and evolutionary questions. This holistic approach to the biology of giant viruses allowed for inspiring discussions and a fruitful exchange of ideas, and resulted in the unanimous call for a follow-up meeting in 2015. In this special issue of Virology, we highlight some of the stories that were presented during the 2013 Ringberg Symposium. We are grateful to the authors for the time and effort they put into their contributions and to Elsevier for making all papers in this special issue open access. Although the field of giant virus research is still a young one, it has already achieved a remarkable feat by changing the way we think about viruses, and we eagerly await future developments.
La Scola, B., Desnues, C., Pagnier, I., Robert, C., Barrassi, L., Fournous, G., Raoult, D., 2008. The virophage as a unique parasite of the giant mimivirus. Nature 455 (7209), 100–104. http://dx.doi.org/10.1038/nature07218. Legendre, M., Bartoli, J., Shmakova, L., Jeudy, S., Labadie, K., Adrait, A., Claverie, J.-M, 2014. Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology. Proc. Natl. Acad. Sci. USA. , http: //dx.doi.org/10.1073/pnas.1320670111. Philippe, N., Legendre, M., Doutre, G., Coute, Y., Poirot, O., Lescot, M., Abergel, C., 2013. Pandoraviruses: amoeba viruses with genomes Up to 2.5 Mb reaching that of parasitic eukaryotes. Science 341 (6143), 281–286. http://dx.doi.org/ 10.1126/science.1239181. Raoult, D., Audic, S., Robert, C., Abergel, C., Renesto, P., Ogata, H., Claverie, J.-M., 2004. The 1.2-megabase genome sequence of Mimivirus. Science 306 (5700), 1344–1350. http://dx.doi.org/10.1126/science.1101485.
Editor Matthias G. Fischer n Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany E-mail address: mfi[email protected]
Editor Richard C. Condit University of Florida, P.O. Box 100266, Gainesville, FL 32610, USA E-mail address: condit@ufl.edu
Available online 28 August 2014
References Colson, P., De Lamballerie, X., Yutin, N., Asgari, S., Bigot, Y., Bideshi, D.K., Raoult, D., 2013. “Megavirales”, a proposed new order for eukaryotic nucleocytoplasmic large DNA viruses. Arch. Virol. 158 (12), 2517–2521. http://dx.doi.org/10.1007/ s00705-013-1768-6.
n
Corresponding author.
