Transposable Element Histories Across a Broad Sampling of Panicoid Grasses

We have employed C value measurements and sample sequence analysis on total cellular DNA to investigate the types and abundances of highly repetitive DNAs across 19 grass species within the subfamily Panicoideae.  Repetitive sequences in next generation sequence data were clustered and assembled into pseudomolecules that were then compared to the broadest databases of known transposable elements (TEs) from previously-characterized plant genomes.  When compared to detailed phylogenetic trees and the determined genome sizes of the investigated species, we were able to discover the differing and conserved activities of individual TE families and subfamilies, to characterize the evolutionary histories of other repeat types, and to investigate apparent cases of horizontal DNA transfer.   Taken together, these results indicate the very different dynamics of genome content that can arise even in very closely related lineages, indicating extreme variability in the suppression, removal and/or activation of repetitive DNAs in grass genomes.