Footprints of inversions at present and past pseudoautosomal boundaries in human sex chromosomes.

ABSTRACT: The human sex chromosomes have stopped recombining gradually, which has left five evolutionary strata on the X chromosome. Y inversions are thought to have suppressed X-Y recombination but clear evidence is missing. Here, we looked for such evidence by focusing on a region--the X-added region (XAR)--that includes the pseudoautosomal region and the most recent strata 3 to 5. We estimated and analyzed the whole set of parsimonious scenarios of Y inversions given the gene order in XAR and its Y homolog. Comparing these to scenarios for simulated sequences suggests that the strata 4 and 5 were formed by Y inversions. By comparing the X and Y DNA sequences, we found clear evidence of two Y inversions associated with duplications that coincide with the boundaries of strata 4 and 5. Divergence be

SUBMITTER: Lemaitre C 

PROVIDER: S-EPMC2817401 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature