The mouse genome contains a major and a minor satellite DNA family of repetitive 
DNA sequences. The use of 5-azacytidine has allowed us to demonstrate that these 
satellite DNAs are organized in two separate domains at the centromeres of mouse 
chromosomes. The minor satellite is closer to the short arms of the acrocentric 
chromosomes than the major satellite. The major satellite is farther away, 
flanking the minor satellite and adjacent to the euchromatic long arm of each 
mouse chromosome. At the level of resolution afforded by the in situ 
hybridization technique it would appear that the organization of the centromeric 
domain of the mouse is similar to that in man. That is, both contain two 
repetitive DNA sequence families arranged in major blocks.