Figure 3

ClustalW alignment of repeats from alphoid array D21Z1 of chromosome 21, E1-E3 (E4-E6 are shown in Additional file 1). The DVNs are shown in the upper line, with their positions along the 1866 bp long HOR. A minority of them are shared by the six homologues. 19 (E1), 11 (E2), 12 (E3) repeats exhibit no DVNs at all; they might, however, differ by a few sporadic mutations (less than 0.2% on average).