title: Stable length polymorphism of up to 260 kb at the tip of the short arm of human chromosome 16.
abstract: We have completed a long-range restriction map of the terminal region of the short arm of human chromosome 16 (16p13.3) by physically linking a distal genetic locus (alpha-globin) with two recently isolated probes to telomere-associated repeats (TelBam3.4 and TelBam-11). Comparison of 47 chromosomes has revealed major polymorphic length variation in this region: we have identified three alleles in which the alpha-globin genes lie 170 kb, 350 kb, or 430 kb from the telemere. The two most common alleles contain different terminal segments, starting 145 kb distal to the alpha-globin genes. Beyond this boundary these alleles are nonhomologous, yet each contains sequences related to other (different) chromosome termini. This chromosome size polymorphism has probably arisen by occasional exchanges between the subtelomeric regions of nonhomologous chromosomes; analogous length variation is likely to be present at other human telomeres.
authors.affiliation: Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford, England.
authors.forename: A O
authors.initials: AO
authors.lastname: Wilkie
authors.forename: D R
authors.initials: DR
authors.lastname: Higgs
authors.forename: K A
authors.initials: KA
authors.lastname: Rack
authors.forename: V J
authors.initials: VJ
authors.lastname: Buckle
authors.forename: N K
authors.initials: NK
authors.lastname: Spurr
authors.forename: N
authors.initials: N
authors.lastname: Fischel-Ghodsian
authors.forename: I
authors.initials: I
authors.lastname: Ceccherini
authors.forename: W R
authors.initials: WR
authors.lastname: Brown
authors.forename: P C
authors.initials: PC
authors.lastname: Harris
mesh_terms: D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D002875:Chromosomes / Q000648:ultrastructure*; D002885:Chromosomes, Human, Pair 16; D005914:Globins / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D011110:Polymorphism, Genetic; D015183:Restriction Mapping
chemical_list: D009841:Oligonucleotides; D005914:Globins