Inter- and intra-specific gene-density-correlated radial chromosome territory arrangements are conserved in Old World monkeys

Recently it has been shown that the gene-density correlated radial
distribution of human 18 and 19 homologous chromosome territories
(CTs) is conserved in higher primates in spite of chromosomal
rearrangements that occurred during evolution. However, these
observations were limited to apes and New World monkey species. In
order to provide further evidence for the evolutionary conservation
of gene-density-correlated CT arrangements, we extended our
previous study to Old World monkeys. They comprise the remaining
species group to be analyzed in order to obtain a comprehensive
overview of the nuclear topology of human 18 and 19 homologous CTs
in higher primates. In the present study we investigated four
lymphoblastoid cell lines from three species of Old World monkeys
by three-dimensional fluorescence in situ hybridization (3D-FISH):
two individuals of Japanese macaque ( Macaca fuscata), crab-eating
macaque ( Macaca fascicularis), and an interspecies hybrid
individual between African green monkey (Cercopithecus aethiops)
and Patas monkey ( Erythrocebus patas). Our data demonstrate that
gene-poor human 18 homologous CTs are located preferentially close
to the nuclear periphery, whereas gene-dense human 19 homologous
CTs are oriented towards the nuclear center in all cell lines
analyzed. The gene-density-correlated positioning of human 18 and
19 homologous CTs is evolutionarily conserved throughout all major
higher primate lineages, despite chromosomal inversions, fusions,
fissions or reciprocal translocations that occurred in the course
of evolution in these species. This remarkable preservation of a
gene-density-correlated chromatin arrangement gives further support
for a functionally relevant higher-order chromatin architecture.
Copyright (C) 2005 S. Karger AG, Basel.