title: Impact of transposable elements on the organization and function of allopolyploid genomes.
abstract: Transposable elements (TEs) represent an important fraction of plant genomes and are likely to play a pivotal role in fuelling genome reorganization and functional changes following allopolyploidization. Various processes associated with allopolyploidy (i.e. genetic redundancy, bottlenecks during the formation of allopolyploids or genome shock following genome merging) may allow accumulation of TE insertions. Our objective in carrying out a survey of the literature and a comparative analysis across different allopolyploid systems is to shed light on the structural, epigenetic and functional modifications driven by TEs during allopolyploidization and subsequent diploidization. The available evidence indicates that TE proliferation in the short or the long term after allopolyploidization may be restricted to a few TEs, in specific polyploid systems. By contrast, data indicate major structural changes in the TE genome fraction immediately after allopolyploidization, mainly through losses of TE sequences as a result of recombination. Emerging evidence also suggests that TEs are targeted by substantial epigenetic changes, which may impact gene expression and genome stability. Furthermore, TEs may directly or indirectly support the evolution of new functionalities in allopolyploids during diploidization. All data stress allopolyploidization as a shock associated with drastic genome reorganization. Mechanisms controlling TEs during allopolyploidization as well as their impact on diploidization are discussed.
authors.affiliation: Laboratoire de Biologie Cellulaire, Institut Jean-Pierre Bourgin, INRA, 78026 Versailles, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Parisod
authors.forename: Karine
authors.initials: K
authors.lastname: Alix
authors.forename: Jérémy
authors.initials: J
authors.lastname: Just
authors.forename: Maud
authors.initials: M
authors.lastname: Petit
authors.forename: Véronique
authors.initials: V
authors.lastname: Sarilar
authors.forename: Corinne
authors.initials: C
authors.lastname: Mhiri
authors.forename: Malika
authors.initials: M
authors.lastname: Ainouche
authors.forename: Boulos
authors.initials: B
authors.lastname: Chalhoub
authors.forename: Marie-Angèle
authors.initials: MA
authors.lastname: Grandbastien
mesh_terms: D005075:Biological Evolution; D004251:DNA Transposable Elements / Q000235:genetics*; D018745:Genome, Plant / Q000235:genetics*; D011123:Polyploidy; D013997:Time Factors
chemical_list: D004251:DNA Transposable Elements