Amplicons formed by two genomic regions, initially located on the different chromosomes. Chromosome 8 and 9 copy number profiles showing amplification on (a) 9q and (b) 8q. (c) Organization of the amplicon. CTD-3145B15 (red) maps to the 9q telomere near the DHFR* insertion site and RP11-237F24 (green) to the region of amplification on chromosome 8 shown in (b). The chromosome 9 signals appear to flank the chromosome 8 material on this chromosome. Amplification of the region around DHFR* is indicated by the large hybridization signal from CTD-3145B15. The amplified DNA was determined to be located on chromosome 9 by hybridization of RP11-62H18 to 9pter (not shown). Thus, material from 9qter appears to be amplified in situ on chromosome 9 and additional copies of material from the chromosome 9 amplicon are present on a separate chromosome together with amplified DNA from chromosome 8. (d, e) Copy number profiles of chromosomes 19 (d) and 8 (e). (f) Organization of the amplicon. RP11-691H23 (red) maps near the DHFR* integration site on chromosome 19 and RP11-175H20 (green) is one of the clones from the amplicon on chromosome 8 shown in (e). The chromosome 19 signals appear to flank a number of copies of chromosome 8, which could be as many as eight copies, since the CGH log2 ratio = ~2. Two additional copies of RP11-691H23, mapping near DHFR* on chromosome 19, were also present on chromosome 19 (data not shown). Thus, amplified DNA near the DHFR* integration site is present and independently amplified on two chromosomes. (g, h) 1M-42_9 CGH profile (chromosome 8) showing the DHFR* amplicon and its organization as determined by FISH. BAC clone RP11-91O11 (red) maps near the DHFR* integration site and is co-amplified with the distal part of chromosome 8 (RP11-237F24, green). The chromosomal region between the two co-amplified regions was lost. (i, j) 1M-42_2 CGH profile (chromosome 8) and FISH analysis showing that the two regions of chromosome 8 were amplified as two independent amplicons on different chromosomes.