Erratum from-polyploid evolution in spartina: Dealing with highly redundant hybrid genomes

Abstract

Polyploidy and recurrent interspecific hybridization represent major features of Spartina evolution, resulting in several superimposed divergent genomes that coexist in the currently living species. This chapter summarizes what we presently know about Spartina history, emphasizing the recent hybridization and polyploidization events that have important ecological and evolutionary consequences. Particular attention is devoted to the recent formation of the allododecaploid invasive Spartina anglica, a salt-marsh ecosystem engineer that resulted from hybridization between the hexaploid S. alterniflora (introduced from North America) and tetraploid S. maritima (a European native) and subsequent genome duplication of the F 1 hybrid S. x townsendii during the nineteenth century in Western Europe. Allopolyploidy was not accompanied by substantial restructuring of the parental genomes, as observed in some other allopolyploid systems. The major evolutionary events affect the regulatory systems controlling gene expression (including epigenetic regulation), which appear to have been profoundly altered by the merger of different genomes. Methodological challenges in exploring non-model, highly redundant genomes resulting from superimposed events of polyploidization (such as those encountered in Spartina) and the contribution of the new massive parallel sequencing technologies are discussed.