It is known that human chromosome 2 originated from the fusion of two ancestral 
primate chromosomes. This has been confirmed by chromosome banding and 
fluorescence in-situ hybridization (FISH) with human chromosome-2-specific DNA 
libraries. In this study, the order of 38 cosmid clones derived from the human 
chromosome region 2q12-q14 was exactly determined by high-resolution FISH in 
human chromosome 2 and its homologous chromosomes in chimpanzees (Pan 
trogrodydes, 2n=48) and cynomolgus monkeys (Macacafascicularis, 2n = 42). This 
region includes the telomere-to-telomere fusion point of two ancestral ape-type 
chromosomes. As a result of comparative mapping, human chromosome region 
2q12-q14 was found to correspond to the short arms of chimpanzee chromosomes 12 
and 13 and cynomolgus monkey chromosomes 9 and 15. It is noted that no 
difference was detected in the relative order of the cosmid clones between human 
and chimpanzee chromosomes. This suggests that two ancestral ape-type 
chromosomes fused tandemly at telomeres to form human chromosome 2, and the 
genomic organization of this region is thought to be considerably conserved. In 
the cynomolgus monkey, however, the order of clones in each homologue was 
inverted. In addition to cosmid mapping, two chromosome-2-specific yeast 
artificial chromosome (YAC) clones containing the fusion point were identified 
by FISH.