In   the  interphase  nucleus,  each
   chromosome  occupies a discrete chromosome territory, and is separated
   from  other  chromosomes  by  an  interchromosomal  domain, where much
   transcription activity occurs.

   Euchromatin  (open,  frequently  transcribed)  replicates  in  early S
   phase, heterochromatin replicates in late S phase.

   Channels between chromosomes are called interchromosomal compartments.

   Chromosome    structure    is    continuously   rearranged   so   that
   transcriptionally  active  genes are cycled to the edges of chromosome
   territories.