Niemeyer Virus: A New Mimivirus Group A Isolate Harboring a Set of Duplicated Aminoacyl-tRNA Synthetase Genes.

Paulo V. M. Boratto,Jônatas S. Abrahão,Erna G. Kroon,Felipe L. Assis,Thalita S. Arantes,Bernard La Scola,Lorena C. F. Silva

doi:10.3389/fmicb.2015.01256

Abstract

It is well recognized that gene duplication/acquisition is a key factor for molecular evolution, being directly related to the emergence of new genetic variants. The importance of such phenomena can also be expanded to the viral world, with impacts on viral fitness and environmental adaptations. In this work we describe the isolation and characterization of Niemeyer virus, a new mimivirus isolate obtained from water samples of an urban lake in Brazil. Genomic data showed that Niemeyer harbors duplicated copies of three of its four aminoacyl-tRNA synthetase genes (cysteinyl, methionyl, and tyrosyl RS). Gene expression analysis showed that such duplications allowed significantly increased expression of methionyl and tyrosyl aaRS mRNA by Niemeyer in comparison to APMV. Remarkably, phylogenetic data revealed that Niemeyer duplicated gene pairs are different, each one clustering with a different group of mimivirus strains. Taken together, our results raise new questions about the origins and selective pressures involving events of aaRS gain and loss among mimiviruses.

Highlights

Since the discovery of the first member of the family Mimiviridae, Acanthamoeba polyphaga mimivirus (APMV), in 2003, more mimivirus-like viruses are being isolated with increasing frequency from phagotrophic protists (La Scola et al, 2003)
We report the isolation of Niemeyer virus (NYMV) from water samples collected in an urban lake in Brazil
In this work we describe the isolation of NYMV, a new mimivirus group A isolate from an aquatic habitat marked by a high concentration of organic matter, the eutrophicated urban lake Pampulha Lagoon (Figure 1A)

Summary

Introduction

Since the discovery of the first member of the family Mimiviridae, Acanthamoeba polyphaga mimivirus (APMV), in 2003, more mimivirus-like viruses are being isolated with increasing frequency from phagotrophic protists (La Scola et al, 2003). The family Mimiviridae consists of dozens of mimivirus-like isolates that are able to infect amoeba of the genus Acanthamoeba. These viruses have been grouped into three distinct lineages, according to their polymerase B gene sequence and other genetic markers: lineage A (containing APMV), lineage B (containing Acanthamoeba polyphaga moumouvirus) and lineage aaRS duplications in Niemeyer mimivirus

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Conclusion