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.
Chen
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Center for Medical Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-3914.
Lowther
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Avramopoulos
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Antonarakis
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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