title: How endogenous plant pararetroviruses shed light on Musa evolution.
abstract: OBJECTIVE
  Banana genomes harbour numerous copies of viral sequences derived from banana streak viruses (BSVs) - dsDNA viruses belonging to the family Caulimoviridae.These viral integrants (eBSVs) are mostly defective, probably as a result of 'pseudogenization' driven by host genome evolution. However, some can give rise to infection by releasing a functional viral genome following abiotic stresses. These distinct infective eBSVs correspond to the three main widespread BSV species (BSOLV, BSGFV and BSIMV), fully described within the Musa balbisiana B genomes of the seedy diploid 'Pisang Klutuk Wulung' (PKW).
  
  
  METHODS
  We characterize eBSV distribution among a Musa sampling including seedy BB diploids and interspecific hybrids with Musa acuminate exhibiting different levels of ploidy for the B genome (ABB, AAB, AB). We used representative samples of the two areas of sympatry between M. acuminate and M. balbisiana species representing the native area of the most widely cultivated AAB cultivars (in India and in East Asia, ranging from the Philippines to New Guinea). Seventy-seven accessions were characterized using eBSV-related PCR markers and Southern hybridization approaches. We coded both sets of results to create a common dissimilarity matrix with which to interpret eBSV distribution.
  
  
  RESULTS
  We propose a Musa phylogeny driven by the M. balbisiana genome based on a dendrogram resulting from a joint neighbour-joining analysis of the three BSV species, showing for the first time lineages between BB and ABB/AAB hybrids. eBSVs appear to be relevant phylogenetic markers that can illustrate theM. balbisiana phylogeography story.
  
  
  CONCLUSIONS
  The theoretical implications of this study for further elucidation of the historical and geographical process of Musa domestication are numerous. Discovery of banana plants with B genome non-infective for eBSV opens the way to the introduction of new genitors in programmes of genetic banana improvement.
authors.affiliation: CIRAD, UMR BGPI, F-34398 Montpellier Cedex 5, France and.
authors.forename: Pierre-Olivier
authors.initials: PO
authors.lastname: Duroy
authors.affiliation: CIRAD, UMR AGAP, F-34398 Montpellier Cedex 5, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Perrier
authors.affiliation: CIRAD, UMR BGPI, F-34398 Montpellier Cedex 5, France and.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Laboureau
authors.affiliation: CIRAD, UMR AGAP, F-34398 Montpellier Cedex 5, France.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Jacquemoud-Collet
authors.affiliation: CIRAD, UMR BGPI, F-34398 Montpellier Cedex 5, France and marie-line.caruana@cirad.fr.
authors.forename: Marie-Line
authors.initials: ML
authors.lastname: Iskra-Caruana
mesh_terms: D005075:Biological Evolution; D015139:Blotting, Southern; D004171:Diploidy; D060146:Ecotype; D020077:Endogenous Retroviruses / Q000502:physiology*; D014644:Genetic Variation; D005838:Genotype; D028521:Musa / Q000235:genetics / Q000821:virology*; D010802:Phylogeny
keywords: Musa balbisiana; Musa sp.; banana streak virus (BSV); dissimilarity matrix; endogenous pararetrovirus (EPRV); evolution; genetic markers; microsatellite; phylogeny; ploidy