COMPARATIVE MAPPING OF THE CRI DU CHAT AND DIGEORGE-SYNDROME REGIONS IN THE GREAT APES

Structural variations between great ape and human chromosomes due to p ericentric inversions and translocations have created at apparent cont roversy during the reconstruction of hominoid phylogeny. One such vari ation involves human chromosome 5, which is equivalent to chromosome 4 in chimpanzee and orangutan but equivalent to segments of chromosomes 4 and 19 in gorilla. Obviously, neither banding patterns nor centrome ric indecies in these chromosomes match. The pathological condition of cri du chat syndrome is due to the cytogenetic deletion of band p15.2 of chromosome 5. Is this region involved during pericentric inversion of apes chromsome 4? We used a human cosmid probe for cri du chat syn drome as a phylogenetic marker in search of the aforementioned questio n. The genomic sequences for cri du chat syndrome region were conserve d in chimpanzee (PTR4) and orangutan (PPY4) but displayed a positional divergence in gorilla on chromosome 19(GGO19). In addition, we used a human cosmid DNA probe for DiGeorge syndrome which is located on chro mosome 22 band q11.2 and was conserved within band 23q11.2 in apes. Th e loci specific human genomic probes may help to describe the inversio ns and translocations for other chromsomes.