Chromosome territories. Chromosome territories. In mammalian cells, individual chromosomes appear to occupy a restricted nuclear volume—a chromosome territory. (A) An example in which a probe to human chromosome 11 (short arm, 11p) has been hybridized to target sequences in a human lymphocyte. Two 11p territories (green) lie against the nuclear periphery. However, when a shorter telomeric probe is used—the subtelomeric region on 11p contains a highly active gene cluster—this region (red foci) is seen to be located outside the territory as defined by the general 11p probe. Although distinct territories can be defined, DNA from the corresponding chromosomal region is able to escape from the territory under some circumstances. (B) The typical arrangement of the same regions as in (A) in human fibroblasts. For details, see Mahy et al, 2002, reproduced by copyright permission of The Rockefeller University Press. (C) Low‐ and high‐resolution models for the architecture of chromosome territories. The low‐resolution model depicts how the chromosome axis is displaced in space. The high‐resolution model emphasizes how DNA foci of approximately 0.5 Mbp DNA contribute to the structure. Different colours represent individual territories. For details, see Cremer & Cremer, 2001, reproduced by copyright permission from Macmillan. Dean Jackson EMBO Rep. 2005;6:213-217 © as stated in the article, figure or figure legend