CLONING AND COMPARATIVE MAPPING OF RECENTLY EVOLVED HUMAN-CHROMOSOME 22-SPECIFIC ALPHA-SATELLITE DNA

We have isolated and characterized a new alphoid probe, named p190.22. Its chromosomal location was investigated using fluorescence in situ hybridization. Under high stringency conditions p190.22 recognizes spe cifically the centromere of chromosome 22. A chromosome 22-specific al phoid subset has been previously reported in the literature (p22/1:2.1 ). The pal tial sequence and the genomic organization comparison stron gly suggests that they recognize distinct subsets both specific for ch romosome 22. The comparative mapping of probes p190.22 and p22/1:2.1 o n chimpanzee (PTR and PPA) and gorilla (GGO) chromosomes was investiga ted The two probes showed different hybridization results. p190.22, in particular, did not show any hybridization signal in these three spec ies, subggesting a recent evolution.