TY - JOUR T1 - New insights into the origin of the B genome of hexaploid wheat: evolutionary relationships at the SPA genomic region with the S genome of the diploid relative Aegilops speltoides. AU - Salse,Jérome, AU - Chagué,Véronique, AU - Bolot,Stéphanie, AU - Magdelenat,Ghislaine, AU - Huneau,Cécile, AU - Pont,Caroline, AU - Belcram,Harry, AU - Couloux,Arnaud, AU - Gardais,Soazic, AU - Evrard,Aurélie, AU - Segurens,Béatrice, AU - Charles,Mathieu, AU - Ravel,Catherine, AU - Samain,Sylvie, AU - Charmet,Gilles, AU - Boudet,Nathalie, AU - Chalhoub,Boulos, Y1 - 2008/11/25/ PY - 2008/06/16/received PY - 2008/11/25/accepted PY - 2008/11/27/pubmed PY - 2009/2/24/medline PY - 2008/11/27/entrez SP - 555 EP - 555 JF - BMC genomics JO - BMC Genomics VL - 9 N2 - BACKGROUND: Several studies suggested that the diploid ancestor of the B genome of tetraploid and hexaploid wheat species belongs to the Sitopsis section, having Aegilops speltoides (SS, 2n = 14) as the closest identified relative. However molecular relationships based on genomic sequence comparison, including both coding and non-coding DNA, have never been investigated. In an attempt to clarify these relationships, we compared, in this study, sequences of the Storage Protein Activator (SPA) locus region of the S genome of Ae. speltoides (2n = 14) to that of the A, B and D genomes co-resident in the hexaploid wheat species (Triticum aestivum, AABBDD, 2n = 42). RESULTS: Four BAC clones, spanning the SPA locus of respectively the A, B, D and S genomes, were isolated and sequenced. Orthologous genomic regions were identified as delimited by shared non-transposable elements and non-coding sequences surrounding the SPA gene and correspond to 35,268, 22,739, 43,397 and 53,919 bp for the A, B, D and S genomes, respectively. Sequence length discrepancies within and outside the SPA orthologous regions are the result of non-shared transposable elements (TE) insertions, all of which inserted after the progenitors of the four genomes divergence. CONCLUSION: On the basis of conserved sequence length as well as identity of the shared non-TE regions and the SPA coding sequence, Ae speltoides appears to be more evolutionary related to the B genome of T. aestivum than the A and D genomes. However, the differential insertions of TEs, none of which are conserved between the two genomes led to the conclusion that the S genome of Ae. speltoides has diverged very early from the progenitor of the B genome which remains to be identified. SN - 1471-2164 UR - https://www.unboundmedicine.com/medline/citation/19032732/New_insights_into_the_origin_of_the_B_genome_of_hexaploid_wheat:_evolutionary_relationships_at_the_SPA_genomic_region_with_the_S_genome_of_the_diploid_relative_Aegilops_speltoides_ L2 - https://bmcgenomics.biomedcentral.com/articles/10.1186/1471-2164-9-555 DB - PRIME DP - Unbound Medicine ER -