Conservation of simple repeat sequences at DXZ4. DXZ4 is represented by a right facing 3-kb monomer. Annotated on this monomer is the region of DXZ4 that is conserved in all primates examined (red box) as well as the location of the three internal simple repeat sequences (blue boxes), which account for all repetitive DNA in DXZ4. The sequence of the simple repeats in human is given immediately below the schematic map and beneath this the nucleotide composition in various other primates is given. Sequences that diverge from the human sequence are highlighted as white writing on a black background. The horizontal lines divide great apes from the lesser apes, Old World monkeys and New World monkeys.