Rsp organization in the D. melanogaster genome. A.) Organization of canonical Rsp repeats as a dimer of Right and Left repeats. B.) Pie charts showing the relative abundances of Right, Left Rsp and their variants, and RlX repeats, across the D. melanogaster genome. h39 is a BAC that maps to the heterochromatic cytological band h39 the target of SD. 80C Rsp corresponds to repeats mapping to cytological band 80C on chromosome 3L. C.) Rsp repeat counts across the euchromatic D. melanogaster genome. Plotted are Rsp repeat counts along each chromosome arm in Mb of the euchromatic genome assembly. Shaded in grey are pericentric heterochromatin regions and black circles correspond to centromeres. A schematic of an assembly of unmapped BACs appears above the chromosome plots showing that blocks of Rsp repeats (in black) occur in clusters and are interspersed in the heterochromatin.