| First Author | Lovell D | Year | 1981 |
| Journal | Mouse News Lett | Volume | 65 |
| Pages | 50-1 | Mgi Jnum | J:15088 |
| Mgi Id | MGI:63226 | Citation | Lovell D, et al. (1981) A new mutant causing hairloss in the DBA/1/Lac colony. Mouse News Lett 65:50-1 |
| abstractText | Full text of MNL contribution: A new mutant causing hairloss in the DBA/1/Lac colony. In April 1978 a pair of normal DBA/l mice from the 53rd generation of brother x sister matings produced a litter of 3 hairless males and one normal female. The hairless males failed to survive to breeding age but the female was crossed to a male from the main DBA/1 colony and her offspring mated together at random. Eventually in January 1979 one pair produced three litters containing a total of three hairless males. (The original pair produced no further mutant animals). The mutant mice are distinguishable at birth by the reduced number of vibrissae (they are similar in this respect to homozygous nude (nu) animals). Although they appear to begin developing a coat, by about 7-8 days of age the coat is seen to be abnormal with a thin greasy appearance. By three weeks of age this coat is lost and only small patches of hair remain usually on the underside. The mutant is by then usually smaller than the normal litter mates and often runtish. Large proportions of the mutant animals die just before or after weaning. A small proportion of mutant animals survive for some time after weaning and a small number of the males have successfully produced litters. Some animals which survive past weaning sometimes suddenly develop nearly normal coats only to lose them again within a week to a fortnight. The mutant appears to be inherited as an autosomal recessive. The following table shows the results of ten matings between probable heterozygotes. No. of matings: 10; No. litters born: 30; Mutant males: 19; Normal males: 60; Mutant females: 16; Normal females: 62. Only 5 animals out of 162 animals born in these litters died before their phenotype could be ascertained. In the early stages of production of this mutant there seemed a preponderance of males but the results of these crosses are close to the expected 3:1 ratio for an autosomal recessive. Although the new mutant is phenotypically similar in appearance to the nude mouse post mortem examinations have revealed that the mutants have apparently normal thymuses. While tests for allelism with the other two coat mutations held by the LAC (hairless (hr) and nude (nu)) are not yet complete there is no evidence for the new mutant being allelic to either of them. There are, of course, a considerable number of mutants affecting the coat of the animal and until allelism tests are carried out against each of these it will not be possible to know whether this is a remutation of an existing mutant or a mutation at a new gene locus. The LAC intend to maintain the gene on the inbred DBA/1 background and to continue investigations into what causes the high mortality around weaning and to investigate any immunological or pathological abnormality in the mutant. The mutant has provisionally been assigned the name coatloss (cls); it is hoped to start experiments to determine the mutant's position on the chromosome map in the near future. |
