EXPERIMENTAL FIGURE 8-38 Chromosomal translocations can be analyzed using chromosome painting. Characteristic chromosomal translocations are associated with certain genetic disorders and specific types of cancers. For example, in nearly all patients with chronic myelogenous leukemia, the leukemic cells contain the Philadelphia chromosome, a shortened chromosome 22 [der (22)], and an abnormally long chromosome 9 [der (9)] (“der” stands for derivative). These forms result from a translocation between normal chromosomes 9 and 22. This translocation can be detected (a) by classical banding analysis or (b) by chromosome painting.

[Part (b) courtesy of J. Rowley and R. Espinosa.]