Fluorescence in situ hybridization to chromosomes as a tool to understand human and primate genome evolution

For the last 15 years molecular cytogenetic techniques have been
extensively used to study primate evolution. Molecular probes were
helpful to distinguish mammalian chromosomes and chromosome
segments on the basis of their DNA content rather than solely on
morphological features such as banding patterns. Various landmark
rearrangements have been identified for most of the nodes in
primate phylogeny while chromosome banding still provides helpful
reference maps. Fluorescence in situ hybridization ( FISH)
techniques were used with probes of different complexity including
chromosome painting probes, probes derived from chromosome
sub-regions and in the size of a single gene. Since more recently,
in silico techniques have been applied to trace down evolutionarily
derived chromosome rearrangements by searching the human and mouse
genome sequence databases. More detailed breakpoint analyses of
chromosome rearrangements that occurred during higher primate
evolution also gave some insights into the molecular changes in
chromosome rearrangements that occurred in evolution. Hardly any
``fusion genes{''} as known from chromosome rearrangements in
cancer cells or dramatic ``position effects{''} of genes
transferred to new sites in primate genomes have been reported yet.
Most breakpoint regions have been identified within gene poor areas
rich in repetitive elements and/or low copy repeats ( segmental
duplications). The progress in various molecular and
molecular-cytogenetic approaches including the recently launched
chimpanzee genome project suggests that these new tools will have a
significant impact on the further understanding of human genome
evolution. Copyright (C) 2005 S. Karger AG, Basel.