title: Isolation and characterization of a human variable copy number tandem repeat at Xcen-p11.22.
abstract: A subclone (M27B) has been isolated from a cosmid randomly selected from a library enriched for human X-chromosomal material. The subclone is extensively single-copy sequence, but also contains three complete copies and one partial copy of a 26-bp repeat, within which exists an inverted repeat having the potential to form a cruciform loop structure. Genomic sequences in this repeat region are apparently refractory to cloning, and rearrangements occurring during this process result in deletions. M27B detects multiple X-linked restriction fragments for a wide range of enzymes including MspI and HpaII. We have assigned the locus recognized by the probe (DXS255) to Xcen-Xp11.4 by mapping with a somatic cell hybrid panel and further refined its localization to Xp11.22 by in situ hybridization. The repeat sequence that is presumed to be responsible for the hypervariability observed does not show close similarity to other variable copy number tandem repeats described.
authors.affiliation: Genetics Laboratory, University of Oxford, United Kingdom.
authors.forename: N J
authors.initials: NJ
authors.lastname: Fraser
authors.forename: Y
authors.initials: Y
authors.lastname: Boyd
authors.forename: I
authors.initials: I
authors.lastname: Craig
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003360:Cosmids; D004247:DNA / Q000235:genetics* / Q000302:isolation & purification; D015342:DNA Probes; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D008677:Metaphase; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D012150:Polymorphism, Restriction Fragment Length; D012091:Repetitive Sequences, Nucleic Acid; D014960:X Chromosome
chemical_list: D015342:DNA Probes; D005819:Genetic Markers; D004247:DNA