Conventionally, chromosome morphology can only be observed in a condensed state of a mitotic phase of a cell cycle. However, owing to recent developments in visualization techniques (3D-FISH, confocal laser microscopy), it has become possible to observe the positioning and morphology of chromosomes in an interphase of a cell cycle. In accordance with such visualization techniques it has become clear that, within the nucleus of a cell in an interphase, individual chromosomes are present separately in regions that are not intermingled with each other (Non-patent Publication 1, Non-patent Publication 2). Hereinafter, the region occupied by an individual chromosome within the nucleus is called a chromosome territory.
[Non-patent Publication 1]
T. Cremer, C. Cremer, CHROMOSOME TERRITORIES NUCLEAR ARCHITECTURE AND VENE REGULATION IN MAMMALIAN CELLS, NATURE REVIEWS/GENETICS, vol. 2, pp. 292-301, 2001
[Non-patent Publication 2]
Hideyuki Tanabe, ‘Chromosome territory: recent advancement of studies on interphase chromosome intranuclear positioning in relation to nuclear architecture’, Environ. Mutagen Res., 25, pp. 11 to 22, 2003
[Patent Publication 1]
Japanese Laid-open Patent Publication No. 2001-92980