Figure 2

Karyotypes. (A,B) Metaphase spread figures of S2R + cells (A) and as aligned in karyograms (B). Either wild-type, or close to wild-type chromosome 2 s and 3 s are designated with ‘2’ and ‘3’. If rearrangements were found on them, such as deletions, inversion or translocations, they are marked with ‘r’ (2r and 3r). Small chromosomes that carried euchromatic material appended to a centromeric region that was likely to derive from a large autosome are labeled as ‘am’. Chromosomes whose origin could not be determined are labeled ‘nd’. (C) Chromosome numbers in metaphases from 145 S2R + cells. (D) A heatmap summarizing chromosome numbers. Metaphase spreads for all the cell lines are provided in Additional file 1.