Fig. 2

Sequence composition of CenH3-chromatin (CenH3 ChIP-Seq). Proportional read counts assigned to repeat groups (a), and more specifically to clades and families (b and c). The repeat proportions reflect repeat abundance within sugar beet centromeric sequences. Read counts were normalized to the overall read amount introduced into the clustering approach. a The active centromeres of sugar beet consist mainly of pBV satellite DNA, Ty3-gypsy retrotransposons and of plastid DNA. Only 0.2 % are uncharacterized repeats, consisting of either putative unknown centromeric sequences or truncated repeats. b Satellites of only the pBV family constitute the active centromeres. The most abundant subfamily is pBV_III. c Ty3-gypsy retrotransposons in the active centromeres are exclusively consisting of Beetle families with Beetle7 being the most prominent Ty3-gypsy retrotransposon. Note, that sequences assigned to Beetle2 are most likely sugar beet specific Beetle2 homologs