Recombination between the X and Y chromosomes and the Sxr region of the mouse.
The Sxr (sex-reversed) region that carries a copy of the mouse Y chromosomal testis-determining gene can be attached to the distal end of either the Y or the X chromosome. During male meiosis, Sxr recombined freely between the X and Y chromosomes, with an estimated recombination frequency not significantly different from 50% in either direction. During female meiosis, Sxr recombined freely between the X chromosome to which it was attached and an X-autosome translocation. A male mouse carrying the original Sxra region on its Y chromosome, and the shorter Sxrb variant on the X, also showed 50% recombination between the sex chromosomes. Evidence of unequal crossing-over between the two Sxr regions was obtained: using five markers deleted from Sxrb, 3 variant Sxr regions were detected in 159 progeny (1.9%). Four other variants (one from the original cross and three from later generations) were presumed to have been derived from illegitimate pairing and crossing-over between Sxrb and the homologous region on the short arm of the Y chromosome. The generation of new variants throws light on the arrangement of gene loci and other markers within the short arm of the mouse Y chromosome.
McLaren
A
A
MRC Mammalian Development Unit, London.
Simpson
E
E
Bishop
C E
CE
Mitchell
M J
MJ
Darling
S M
SM
D000818:Animals; D001483:Base Sequence; D003434:Crossing Over, Genetic; D005260:Female; D008297:Male; D008540:Meiosis; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D012732:Sex Determination Analysis; D014960:X Chromosome; D014998:Y Chromosome