Segmental Duplication. A segmental duplication found on the human Y chromosome at positions 8,590,000-11,000,000. The monomer is approximately 20,344 nucleotides, with 9 visible copies spanning an unsequenced region (black). The mega-repeat probably extends through the unsequenced region, with the sequencing gap resulting from alignment difficulties within this repetitive region. Note that the upper and lower sections are not in phase with each other (the diagonal line shows where the first section lines up with the beginning of the second section). This suggests that the length allotted to the unsequenced region may not be correct.