Simian Y chromosomes: species-specific rearrangements of DAZ, RBM, and TSPY versus contiguity of PAR and SRY.

The three human male specific expressed gene families DAZ, RBM, and TSPY are known to be repetitively clustered in the Y-specific region of the human Y Chromosome (Chr). RBM and TSPY are Y-specifically conserved in simians, whereas DAZ cannot be detected on the Y chromosomes of New World monkeys. The proximity of SRY to the pseudoautosomal region (PAR) is highly conserved and thus most effectively stabilizes the pseudoautosomal boundary on the Y (PABY) in simians. In contrast, the non-recombining part of the Y Chrs, including DAZ, RBM, and TSPY, was exposed to species-specific amplifications, diversifications, and rearrangements. Evolutionary fast fixation of any of these variations was possible as long as they did not interfere with male fertility.