Mapping studies of the centromeric region of the human Y chromosome
Mapping studies of the centromeric region of the human Y chromosome Construction of a map of a human centromeric region is very important in order to understand the organisation of this essential part of the chromosome. A YAC contig map has been assembled of the pericentric 10 Mb of the human Y chromosome, giving coverage of Yp from the large X-Y homologous region through to the alphoid satellite of the centromere, and from the alphoid DNA to the proximal unique sequences on Yq. The Yp map has one remaining gap between TSPY1 and the AMELY region, while two gaps separate the satellite region on Yq from the other two contigs. After constructing the map, the known genes were localised to the region. One Yq gene, DFFRY, was discounted as a potential anti-Turner syndrome gene by analysis of rearranged Y chromosomes. Detection of a block of duplicated sequence on Yp led to the confirmation of the existence of an inversion polymorphism, which was then found to be correlated with a major subclass of sex-reversed individuals, who have X-Y chromosomal breakpoints within the inverted region. These results not only give a far more extensive and detailed map of this region than before, but also show that understanding the organisation of the region has important consequences for a number of genetic disorders.