title: Replication time of interspersed repetitive DNA sequences in hamsters.
abstract: The replication time of 34 hamster genomic DNA segments containing interspersed repeat sequences was determined by probing the cloned segments with nick-translated early- and late-replicating hamster DNA. One-third of these cloned families replicated early, one-third replicated late, and one-third replicated without temporal bias. 19 different inserts from these clones along with the SINE, Alu, and the LINE, A36Fc, were used to probe Southern blots of early- and late-replicating hamster or human DNA. We report long interspersed repeats, LINEs, are selectively partitioned into late-replicating DNA and are often concertedly hypomethylated, while short interspersed repeats, SINEs, are selectively partitioned into early-replicating DNA. For some interspersed repeat families, this partitioning is complete or almost complete. The CCGG frequency is very low in late-replicating DNA. The mammalian chromosome's pattern of early-replicating R-bands and late-replicating G-bands reflects a differential distribution of LINEs and SINEs.
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D004261:DNA Replication; D007158:Immunologic Techniques; D066298:In Vitro Techniques; D008745:Methylation; D009693:Nucleic Acid Hybridization; D012091:Repetitive Sequences, Nucleic Acid; D013997:Time Factors