Figure 5

Karyotype arrays of the rat mammary carcinoma RMT 37–2. The mammary carcinoma RMT 37–2 consisted of two clones with distinct but related karyotype arrays, clones 1 (A) and 2 (B). As shown in the attached table the numbers of chromosomes per RMT 37–2 cell are quasi-clonal, averaging of 43 ± 1 and 42 ± 1 respectively. The copy numbers of the normal and marker chromosomes of the two clones are between 80 and 100% clonal. Both RMT 37–2 clones shared a monosomy of the normal chromosome 1 and one clonal, oversized chromosome 1-derived marker chromosome, in which about half of the normal chromosome 1 was duplicated (See Figure 2B). On the other hand, clone-1 differed from clone-2 in a clone-1-specific monosomy 7, a trisomy 12 and a marker chromosome der(7). And clone 2 differed from clone 1 in a marker chromosome of its own. It follows that the two clones either derived from a common ancestor or from each other. The individuality of the two RMT 37–2 karyotypes is evident from comparisons with the karyotype arrays of RMT 47–3 and the normal rat shown in Figure 3.