Analysis of sex-chromosome aneuploidy in interspecific backcross progeny between the laboratory mouse strain C57BL/6 and Mus spretus.
Sex-chromosomal aneuploidy was identified in four female progeny of 200 interspecific backcrosses between laboratory mice (C57BL/6Ros) and Mus spretus. The progeny included two 39,XO monosomy mice resulting from a backcross with M. spretus, as well as a 41,XXX trisomic mouse and a 40,XX/41,XXX mosaic mouse resulting from two separate backcrosses with C57BL/6 mice. The parental origin and meiotic stage of the aneuploidies was determined for each of the mice using a series of markers that identified allelic differences in the parental X-chromosome genes present in the hybrid female. Two of the probes identified differences in repeated elements between the M. spretus and laboratory mouse X chromosomes, whereas the remaining sites involved restriction fragment length differences of single-copy genes detectable by Southern analysis. These markers indicated that the aneuploidies were most likely of maternal origin and that the trisomy resulted from a nondisjunction at the second meiotic division. In contrast, the mosaic female could have originated either from a trisomic embryo that had lost a single X in a portion of its cells or from a mitotic nondisjunction during early embryogenesis that resulted in XXX and XO daughter cells, with subsequent loss of the XO cells.
Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, NY 14263.
Y
Y
Matsuda
V M
VM
Chapman
D000782:Aneuploidy; D000818:Animals; D015139:Blotting, Southern; D003433:Crosses, Genetic; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics; D009115:Muridae / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D014960:X Chromosome