RT Journal Article
T1 Amplification, contraction and genomic spread of a satellite DNA family (E180) in Medicago (Fabaceae) and allied genera
A1 Rosato, Carmen Luisa Marcela
A1 Galián, José
A1 Rosselló, Josep
AB Background and AimsSatellite DNA is a genomic component present in virtually all eukaryotic organisms. The turnover of highly repetitive satellite DNA is an important element in genome organization and evolution in plants. Here we assess the presence and physical distribution of the repetitive DNA E180 family in Medicago and allied genera. Our goals were to gain insight into the karyotype evolution of Medicago using satellite DNA markers, and to evaluate the taxonomic and phylogenetic signal of a satellite DNA family in a genus hypothesized to have a complex evolutionary history. MethodsSeventy accessions from Medicago, Trigonella, Melilotus and Trifolium were analysed by PCR to assess the presence of the repetitive E180 family, and fluorescence in situ hybridization (FISH) was used for physical mapping in somatic chromosomes. Key ResultsThe E180 repeat unit was PCR-amplified in 37 of 40 taxa in Medicago, eight of 12 species of Trigonella, six of seven species of Melilotus and in two of 11 Trifolium species. Examination of the mitotic chromosomes revealed that only 13 Medicago and two Trigonella species showed FISH signals using the E180 probe. Stronger hybridization signals were observed in subtelomeric and interstitial loci than in the pericentromeric loci, suggesting this satellite family has a preferential genomic location. Not all 13 Medicago species that showed FISH localization of the E180 repeat were phylogenetically related. However, nine of these species belong to the phylogenetically derived clade including the M. sativa and M. arborea complexes. ConclusionsThe use of the E180 family as a phylogenetic marker in Medicago should be viewed with caution. Its amplification appears to have been produced through recurrent and independent evolutionary episodes in both annual and perennial Medicago species as well as in basal and derived clades.
PB Oxford Academic
SN 1095-8290
YR 2011
FD 2011
LK https://hdl.handle.net/20.500.14352/95243
UL https://hdl.handle.net/20.500.14352/95243
LA eng
NO This work was supported by funds from the Spanish Ministry of Education and Science [Project CGL2010-22347-C02-01], the Catalan Government [Consolidated Research Group 2009SGR608] and by a PhD grant from the Spanish Ministry of Education and Science to J.A.G.
NO Generalitat de Catalunya
NO Ministerio de Educación (España)
DS Docta Complutense
RD 8 jun 2025