Sequence analysis of cloned human satellite DNAs reveals nonrandom variations.
We have cloned, from the genome of HeLa cells, related 1.8-kb highly repetitive EcoRI satellite II (and III) DNA family members that displayed a high degree of TaqI and HinfI variations. Comparative sequence analysis of these cloned DNAs suggests that highly repetitive satellite DNAs may have evolved and diversified from the rapid amplification of a pentameric unit (5' TTCCA 3'), by processes including random and non-random mutations. Base conservation, as well as mutational hotspots, were found associated with these related satellite II and III DNAs. The accumulation of C to G transversions within the pentamers, generating TaqI and HinfI sites, as well as C to T transitions at CpN dinucleotides, appear to be responsible for much of the microheterogeneity observed between related satellite II and III DNA family members.
Department of Microbiology and Immunology, McGill University, Montréal, Que., Canada.
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D001483:Base Sequence; D003001:Cloning, Molecular; D004276:DNA, Satellite; D015252:Deoxyribonucleases, Type II Site-Specific; D014644:Genetic Variation; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D017421:Sequence Analysis
D004276:DNA, Satellite; D015252:Deoxyribonucleases, Type II Site-Specific; C032229:GANTC-specific type II deoxyribonucleases; C027046:TCGA-specific type II deoxyribonucleases