Extensive evidence indicates that eukaryotic chromosomes are organized
as sets of structural-functional units (domains) that form the basis
of independent gene activity. At present, several types of chromosome
regions have been suggested for the role of putative domain boundaries
between structural-functional units in eukaryotic chromosomes. In thi
s review, the experimental data on several chromosome elements as poss
ible boundaries in eukaryotic chromosomes are presented. They are: scs
/scs'-elements of the Drosophila heat-shock locus, DCR, LCR and the in
sulator of the human and chicken beta-globin locus, as well as MARs (S
ARs) of plant and animal chromosomes.