Partial complementation by murine t haplotypes: deficit of males among t6/tw5 double heterozygotes and correlation with transmission-ratio distortion.
To evaluate whether sex reversal contributes to sex-ratio imbalance among t6/tw5 double heterozygotes, the cross performed by K. B. Bechtol (Genetical Research 39, 1982, 79-84), T/t6 x T/tw5, was repeated. Significantly more normal-tailed (t6/tw5) females than males were recovered. By contrast, sex ratios were normal among tailless progeny resulting from this cross and among all classes produced by control crosses. Hybridization of a Y-specific DNA probe with genomic DNA from phenotypic females revealed no XY, sex-reversed males. On the genetic backgrounds that generated only moderate transmission distortion of tw5 (81-85%), the overall viability of the doubly heterozygous progeny was only 50% and the sex-ratio skew among this class was strong. However, on a genetic background that displayed extreme tw5 transmission (99%), embryonic viability was more than 80% and the sex-ratio imbalance was weak.
King
T R
TR
Laboratory of Genetics, University of Wisconsin-Madison 53706.
D000818:Animals; D012734:Disorders of Sex Development; D005260:Female; D005816:Genetic Complementation Test; D006239:Haplotypes; D006579:Heterozygote; D008297:Male; D051379:Mice; D012744:Sex Ratio; D014998:Y Chromosome