| First Author | Krzanowska H | Year | 1966 |
| Journal | Mouse News Lett | Volume | 35 |
| Pages | 35 | Mgi Jnum | J:15062 |
| Mgi Id | MGI:63205 | Citation | Krzanowska H (1966) Mo. Mouse News Lett 35:35 |
| abstractText | Full text of MNL contribution: New mutation: The sex linked semidominant Mosaic (provisionally designated Ms) appeared spontaneously in our Outbred stock. The mutation is lethal in hemizygous condition (all males die when about 2 - 3 weeks old) but viable in heterozygotes. Some deaths must occur prenatally, as the proportion of mutants born by heterozygous mothers is significantly lower than expected 50% (table). The mutation affects pigmentation and hair structure of vibrissae. In males it decreases the intensity of yellow and of black considerably. It changes the colour of agouti from brownish grey to a purer grey; yellow to ivory; and black to sepia. Sepia hair is characterised by the light (cream) base and the darker tip. A characteristic colour pattern is developed, namely the head and the mid line of the body is darker than the rest. The expression of the gene on brown background is now being investigated. The effect of the mutation is more conspicuous on pp (pink-eyed dilution) background: agouti pink-eyed males (AABBpp) are ivory instead of "orange" and "blue lilac" (aaBBpp) ones are completely white. The females have over the whole coat the areas of unchanged and of mutant type hair. Frequently the patches are arranged in an irregular pattern of transverse bars. The effect is most conspicuous on pp females when white and wild type bars may be seen. On black adult females the effect is scarcely visible but the mutant may be recognised by examining the hair bases which form cream and black patches over the body. Another effect of the gene in both sexes is curling of the vibrissae which allows classification to be made on 1 - 3 days after birth. This effect does not persist in the adults. Table. Characteristics of young born by heterozygous Ms/+ females. No. litters: 14; Mean litter size: 8.5; No mutants: females: 22; males: 24; No. normal: females: 35; males: 38; Proportion of mutants: 0.39x/ x/The deviation from the expected 50% is significant (0.01<P<0.02) |
