Sequential organization of the DUXY locus in the pericentromeric region of Yq11. The orientation of centromere and telomere is shown at the top. Four copies of the DUX gene family (DUXY1-Y4) are clustered as an imperfect tandem repeat within a genomic segment of 30,323 bp. The transcriptional orientation of each copy is indicated by an arrow. Each DUXY copy is enclosed by repeated elements of tandemly repeated simple sequences (68-bp satellite and LSAU repeat; see legend in figure). Whereas the two types of LSAU repeats are constant in size (120-122 bp and 494-497 bp), the 68-bp satellite sequence is highly variable (2004, 1921, 3707, and 7538 bp). At the distal end of the most telomeric 68-bp satellite block, an Alu repeat has been integrated. The centromeric boundary of the DUXY locus is defined by a block of 5-bp satellite sequence, whereas the telomeric boundary is defined by a MER7 repeat.
