Elevated genomic instability in casp8-deficient B-cell lymphomas. (A-B) The genomic instability of bcasp8^−/− B-cell lymphomas (A, tumor 1; and B, tumor 2) was examined by SKY. The left panels show metaphases hybridized with the SKY probe. The matching inverted DAPI staining is shown in the right panels. A multitude of numerical and complex structural rearrangements were observed: dicentric chromosome (*); acentric chromosome (arrowhead), triradial (●), and translocation (arrow). (C) Representative SKY karyotype of bcasp8^−/−p53^−/− tumors showing aneuploidy and chromosomal translocations (46,XX,+X,+1,+2,+5,+11,der(12)t(12;15)(D;F),+13,der(14)dup(14)(?)t(14;15)(E;F),der(15)t(11;15)(E1;D1). (D) Representative diploid metaphase of a lymphoma from bcasp8^−/−p53^−/− mice. The presence of numerous double-minute chromosomes is evident (representatives are indicated with arrows).