The Y* rearrangement in mice: new insights into a perplexing PAR.
In essence, the Y* rearrangement in the mouse is a Y chromosome that has been hijacked by a non-Y centromere attached distal to the pseudoautosomal region (PAR). All the Y-unique material is thought to be unaltered, but the recombinatory behaviour of the Y* with the X during male meioisis led to the conclusion that part of the PAR is inverted. In the course of a cross set up to introduce the X-linked mutation Patchy fur (Paf) into XY* males, the Y* chromosome was found to carry the wild type allele of Paf. Paf maps close to the X PAR boundary, so we hypothesised that the inverted region of the Y* PAR originated from an X chromosome that provided not only an inverted copy of proximal PAR, but also an X PAR boundary together with some adjacent X-unique material that included the Paf locus. This hypothesis was validated by Southern analysis using an X PAR boundary probe to show that Y* has an X PAR boundary. Thus the Y* PAR has resulted from an end to end fusion of an X and a Y PAR. Furthermore, it was shown that in conjunction with this PAR-PAR fusion, there has been deletion of both copies of the distally located pseudoautosomal gene Steroid sulfatase (Sts).
Laboratory of Developmental Genetics, National Institute for Medical Research, Mill Hill, London, UK. pburgoy@nimr.mrc.ac.uk
P S
PS
Burgoyne
S K
SK
Mahadevaiah
J
J
Perry
S J
SJ
Palmer
A
A
Ashworth
D000818:Animals; D003434:Crossing Over, Genetic; D005260:Female; D015321:Gene Rearrangement; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D014960:X Chromosome; D014998:Y Chromosome