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).
Burgoyne
P S
PS
Laboratory of Developmental Genetics, National Institute for Medical Research, Mill Hill, London, UK. pburgoy@nimr.mrc.ac.uk
Mahadevaiah
S K
SK
Perry
J
J
Palmer
S J
SJ
Ashworth
A
A
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