Sequence, higher order repeat structure, and long-range organization of alpha satellite DNA specific to human chromosome 8.
We have characterized alphoid repeat clones derived from a chromosome 8 library. These clones are specific for human chromosome 8, as demonstrated by use of a somatic cell hybrid mapping panel and by in situ hybridization. Hybridization of the clones to HindIII digests of human genomic DNA reveals a complex pattern of fragments ranging in size from 1.3 to greater than 20 kb. One clone, which corresponds in size to the most prevalent genomic HindIII fragment, appears to represent a major higher order repeat in the chromosome 8 centromere. The DNA sequence of this clone reveals a dimeric organization of alphoid monomers. Restriction analysis of two other clones indicates that they are derivatives of this same repeat unit. The chromosome 8 alphoid clones hybridize to EcoRI fragments of genomic DNA ranging up to 1000 kb in length and reveal a high degree of polymorphism between chromosomes. Distribution of higher order repeat units across the centromere was examined by two-dimensional gel electrophoresis. Repeat units of the same size class tended to cluster together in restricted regions of centromeric DNA.
Ge
Y
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Institute for Molecular Biology, University of Houston, Texas 77204.
Wagner
M J
MJ
Siciliano
M
M
Wells
D E
DE
D001483:Base Sequence; D002503:Centromere; D002898:Chromosomes, Human, Pair 8 / Q000648:ultrastructure; D003001:Cloning, Molecular; D004276:DNA, Satellite / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D004276:DNA, Satellite