Evolutionary reshuffling in the Errantivirus lineage Elbe within the Beta vulgaris genome.
LTR retrotransposons and retroviruses are closely related. Although a viral envelope gene is found in some LTR retrotransposons and all retroviruses, only the latter show infectivity. The identification of Ty3-gypsy-like retrotransposons possessing putative envelope-like open reading frames blurred the taxonomical borders and led to the establishment of the Errantivirus, Metavirus and Chromovirus genera within the Metaviridae. Only a few plant Errantiviruses have been described, and their evolutionary history is not well understood. In this study, we investigated 27 retroelements of four abundant Elbe retrotransposon families belonging to the Errantiviruses in Beta vulgaris (sugar beet). Retroelements of the Elbe lineage integrated between 0.02 and 5.59 million years ago, and show family-specific variations in autonomy and degree of rearrangements: while Elbe3 members are highly fragmented, often truncated and present in a high number of solo LTRs, Elbe2 members are mainly autonomous. We observed extensive reshuffling of structural motifs across families, leading to the formation of new retrotransposon families. Elbe retrotransposons harbor a typical envelope-like gene, often encoding transmembrane domains. During the course of Elbe evolution, the additional open reading frames have been strongly modified or independently acquired. Taken together, the Elbe lineage serves as retrotransposon model reflecting the various stages in Errantivirus evolution, and allows a detailed analysis of retrotransposon family formation.
Department of Biology, Dresden University of Technology, D-01062, Dresden, Germany.
Cora
C
Wollrab
Tony
T
Heitkam
Daniela
D
Holtgräwe
Bernd
B
Weisshaar
André E
AE
Minoche
Juliane C
JC
Dohm
Heinz
H
Himmelbauer
Thomas
T
Schmidt
D000595:Amino Acid Sequence; D027461:Beta vulgaris / Q000235:genetics* / Q000821:virology; D032461:Chromosomes, Plant / Q000235:genetics; D019295:Computational Biology / Q000379:methods; D017124:Conserved Sequence; D019143:Evolution, Molecular; D014644:Genetic Variation; D018745:Genome, Plant; D008969:Molecular Sequence Data; D059372:Nucleotide Motifs; D016366:Open Reading Frames; D020161:Physical Chromosome Mapping; D010942:Plant Viruses / Q000145:classification / Q000235:genetics*; D011995:Recombination, Genetic; D018626:Retroelements; D016415:Sequence Alignment; D013045:Species Specificity
D018626:Retroelements