The general usefulness of α-satellite DNA probes for the molecular, genetic, and cytogenetic analysis of the human genome is enhanced by their being chromosome specific. Here, we describe the isolation and characterization of an α-satellite subset specific for human chromosome 2. Three clones, p2-7, p2-8, and p2-11, obtained from an EcoRI-digested lambda phage library from flow-sorted chromosome 2, are specific for the centromere of chromosome 2 by somatic cell hybrid mapping and chromosomal in situ hybridization. Nucleotide sequence analysis identifies the chromosome 2-specific α-satellite subset D2Z1 as a member of the suprachromosomal subfamily II, which is based on a characteristic two-monomer repeat. The D2Z1 subset is further organized as a series of diverged 680-bp tetramers, revealed after digestion of genomic DNA with HaeIII, HindIII, Hinfl, StuI, and XbaI. Using pulsed-field gel electrophoresis (PFGE), probes p2-7, p2-8, and p2-11 detect polymorphic restriction patterns within the α-satellite array. Among 15 different chromosomes 2 (in two two-generation families and one three-generation family), the length of the D2Z1 α-satellite array varied between 1050 and 2900 kb (mean = 1850 kb, SD = 550 kb). The inheritance of the chromosome 2α-satellite arrays and their associated polymorphisms was strictly Mendelian. © 1992.
