ABSTRACT
BACKGROUND:
The question how evolution and speciation
work is one of the major interests of
biology. Especially, genetic including karyotypic evolution within
primates is of special interest due to the close phylogenetic position of
Macaca and
Homo sapiens and the
role as in vivo models in
medical research,
neuroscience,
behavior,
pharmacology,
reproduction and
Acquired Immune Deficiency Syndrome (
AIDS). MATERIALS &
METHODS:
Karyotypes of five
macaque species from South
East Asia and of one
macaque species as well as
mandrill from
Africa were analyzed by high resolution molecular
cytogenetics to obtain new insights into karyotypic evolution of
old world monkeys. Molecular
cytogenetics applying
human probes and probe sets was applied in
chromosomes of
Macaca arctoides,
M. fascicularis, M. nemestrina, M. assamensis, M. sylvanus, M. mulatta and
Mandrillus sphinx. Established two- to multicolor-fluorescence in situ hybridization (FISH) approaches were applied. Locus-specific probes, whole and partial
chromosome paint probes were hybridized. Especially the FISH-banding approach multicolor-banding (MCB) as well as probes oriented towards
heterochromatin turned out to be highly efficient for interspecies comparison.
CONCLUSION:
Karyotypes of all seven studied species could be characterized in detail. Surprisingly, no evolutionary conserved differences were found among
macaques, including
mandrill. Between the seven here studied and phenotypically so different species we expected several via FISH detectable karyoypic and submicroscopic changes and were surprised to find none of them on a molecular
cytogenetic level. Spatial
separation, may explain the speciation and different evolution for some of them, like African M. sylvanus,
Mandrillus sphinx and the South
Asian macaques. However, for the partially or completely overlapping
habitats of the five studied South
Asian macaques the species
separation process can also not be deduced to karyotypic
separation.