Long-range analyses of the centromeric regions of human chromosomes 13, 14 and 21: identification of a narrow domain containing two key centromeric DNA elements.

Alpha-satellite, satellite 3 and satellite 1 DNA have been proposed as candidate components of a functional human centromere. Multiple subfamilies of these three DNA have recently been identified at the pericentric regions of the human acrocentric chromosomes. Using pulsed field gel electrophoresis, we have constructed long-range maps of the various centromeric markers for chromosomes 13, 14 and 21. These maps cover approximately 2.3 megabases of sequence for each chromosome, and the results demonstrate that within this centromeric region, chromosomes 13 and 21 have a similar organization that is partially shared by chromosome 14. A discrete satellite 3 domain was identified on each chromosome within the boundaries of the alpha-satellite DNA. No satellite 1 was detected within the defined centromeric regions suggesting that satellite 1 is not essential for centromere function.