title: A contiguous Not I restriction map of band q22.3 of human chromosome 21.
abstract: A contiguous high-resolution NotI restriction map of the distal region of the long arm of human chromosome 21 was constructed by three strategies: linking clones to identify adjacent pieces of DNA, partial digestion to identify neighboring fragments, and cell line polymorphisms to prove identity or adjacency of DNA fragments. Twenty-nine single-copy DNA probes and five linking clone probes were used to determine the order of 30 Not I fragments, covering 10 megabases of DNA in band q22.3. Smaller Not I fragments occur preferentially in this region, suggesting that band q22.3 is unusually rich in genes, since Not I sites occur almost exclusively in CpG islands. Comparison of the physical map and genetic maps in this region reveals a 10-fold higher than average recombination frequency.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley.
authors.forename: D
authors.initials: D
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Fang
authors.forename: C R
authors.initials: CR
authors.lastname: Cantor
authors.forename: C L
authors.initials: CL
authors.lastname: Smith
mesh_terms: D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002460:Cell Line; D002871:Chromosome Banding; D002891:Chromosomes, Human, Pair 21; D006224:Cricetinae; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D015252:Deoxyribonucleases, Type II Site-Specific; D008040:Genetic Linkage; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D015183:Restriction Mapping; D016615:Telomere / Q000502:physiology
chemical_list: D004247:DNA; D015252:Deoxyribonucleases, Type II Site-Specific; C038565:GCGGCCGC-specific type II deoxyribonucleases