Evidence for mitotic recombination in Wei/+ heterozygous mice.
A number of alleles at coat color loci of the house mouse give rise to areas of wild-type pigmentation on the coats of otherwise mutant animals. Such unstable alleles include both recessive and dominant mutations. Among the latter are several alleles at the W locus. In this report, phenotypic reversions of the Wei allele at the W locus were studied Mice heterozygous in repulsion for both Wei and buff (bf) [i.e. Wei+/+bf] were examined for the occurrence of phenotypic reversion events. Buff (bf) is a recessive mutation, which lies 21 cM from W on the telomeric side of chromosome 5 and is responsible for the khaki colored coat of nonagouti buff homozygotes (a/a; bf/bf). Two kinds of fully pigmented reversion spots were recovered on the coats of a/a; Wei+/+bf mice: either solid black or khaki colored. Furthermore phenotypic reversions of Wei/+ were enhanced significantly following X-irradiation of 9.25-day-old Wei/+ embryos (P less than 0.04). These observations are consistent with the suggestion of a role for mitotic recombination in the origin of these phenotypic reversions. In addition these results rise the intriguing possibility that some W mutations may enhance mitotic recombination in the house mouse.
Panthier
J J
JJ
Unité de Génétique Cellulaire du Collège de France et de l'Institut Pasteur, Groupe de Génétique du Développement de l'Université Paris, France.
Guénet
J L
JL
Condamine
H
H
Jacob
F
F
D000483:Alleles; D000818:Animals; D003433:Crosses, Genetic; D005260:Female; D006579:Heterozygote; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008938:Mitosis; D009154:Mutation; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics*; D011995:Recombination, Genetic; D014965:X-Rays