Homologous loci DXYS156X and DXYS156Y contain a polymorphic pentanucleotide repeat (TAAAA)n and map to human X and Y chromosomes.
We report the isolation and characterization of a polymorphic pentanucleotide repeat (TAAAA)n, which was mapped to human chromosomes X and Y (loci DXYS156X and DXYS156Y) by PCR amplification of DNA from a monochromosomal somatic cell hybrid panel (NIGMS panel 2). The (TAAAA)n repeat of loci DXYS156 occurs within a human LINE element at a position where the consensus sequence contains a single TAAAA motif. In 72 unrelated CEPH individuals seven alleles were detected which ranged in size from 125 to 165 bp in 5 bp intervals. The two largest alleles (160 and 165 bp) were observed only in males, which suggests that they were amplified from the Y chromosome DXYS156Y locus. The other 5 alleles were present in two copies in females and in a single copy in males, which suggests that they were amplified from the X chromosome DXYS156X locus. Locus DXYS156X was polymorphic in CEPH families with an observed heterozygosity in females of 46% (27 of 59). Linkage analysis with DNA markers on the X chromosome revealed significant lod scores for a location of DXYS156X close to markers DXS1002 (theta = 0.000; zeta = 8.43), DXYS1X (theta = 0.015; zeta = 17.3), DXS3, and PGK1 in the region of chromosome Xq13. The sequence of DXYS156Y derived from the 165 bp allele has been deposited in Genbank with accession number X71600.
Center for Medical Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-3914.
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Chen
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Lowther
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Avramopoulos
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Antonarakis
D000483:Alleles; D001483:Base Sequence; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D005260:Female; D008040:Genetic Linkage; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000235:genetics; D010375:Pedigree; D011110:Polymorphism, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D014960:X Chromosome; D014998:Y Chromosome
D017931:DNA Primers; D005819:Genetic Markers; D009838:Oligodeoxyribonucleotides; D004247:DNA