Phylogenetic analysis of Sadhu sequences from Arabidopsis arenosa and Arabidopsis lyrata relative to Arabidopsis thaliana. (a) Maximum parsimony phylogram of A. arenosa (Aa) internal Sadhu sequence clones and related A. thaliana elements. A. arenosa sequences are in blue. (b) Maximum parsimony phylogram of A. lyrata Sadhu sequences >350 bp (Al, purple) and full-length A. thaliana elements. Shaded large numbers indicate Sadhu subfamilies. See to Additional file 4 for DNA sequences of A. lyrata elements. Bootstrap values (percentages) were calculated from 500 bootstrap replicates.