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 pericentric inversions and translocations have created at apparent controversy during the reconstruction of hominoid phylogeny. One such variation 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 centromeric 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 chromosome 4? We used a human cosmid probe for cri du chat syndrome as a phylogenetic marker in search of the aforementioned question. The genomic sequences for cri du chat syndrome region were conserved in chimpanzee (PTR4) and orangutan (PPY4) but displayed a positional divergence in gorilla on chromosome 19(GG019). In addition, we used a human cosmid DNA probe for DiGeorge syndrome which is located on chromosome 22 band q11.2 and was conserved within band 23q11.2 in apes. The loci specific human genomic probes may help to describe the inversions and translocations for other chromosomes.