| First Author | Dickie MM | Year | 1961 |
| Journal | Mouse News Lett | Volume | 25 |
| Pages | 37 | Mgi Jnum | J:99772 |
| Mgi Id | MGI:3583810 | Citation | Dickie MM (1961) Reverse mutations in dilute and agouti. Mouse News Lett 25:37 |
| abstractText | Full text of MNL contribution: Reverse mutations: In the last several years we have made a serious effort to increase the rate of recovery of mutations occurring in our Production Colony. Increased vigilance on the part of the animal caretakers has resulted in a marked increase in the number of mutants recovered. One mutation in particular, from d to D has occurred, with a frequency high enough to make possible a minimum estimate of its rate of occurrence. The production records show that between July 1, 1958 and March 30, 1961, 533, 714 mice of DBA/1 and DBA/2 were weaned. From these mice 7 mutations resembling D have been recovered. Four of these have been tested for linkage with se and have shown no crossing over with it. They are therefore almost certainly true back mutations at the d locus. It can probably be safely assumed that the untested mutants are also back mutations. The observed mutation rate is therefore 7 in 1,067,428 or 6.56 x 10-6. In the same period in the same strains one mutation from a to Aw has been observed and no mutations from b to B. Mutations to A or Aw would not be very striking and could easily be missed but mutations to B should be at least as obvious as those to D. During the same period many mutations at the agouti locus have been recovered from several different strains and hybrids. Four of the mutations were Aw and seven were at. All occurred in mice homozygous for a except one mutation to Aw which occurred in a random bred stock segregating for A and a. The back mutations at the a locus listed in the second edition of Gruneberg are also either to Aw or at. It seems worthwhile to draw attention to the fact that, while mutations at the a locus are common, mutations from a to A are very rare, if they occur at all. All mutants maintained at the Roscoe B. Jackson Memorial Laboratory. Abbreviations: NIB = not inbred SEG = segregating for genes not indicated in genotype F = number of successive generations brother x sister N = number of successive crosses to inbred strains M = mutation occurred in inbred strain NBS = not brother sister bred, but originated from or placed on inbred strain pi+ x pipi = female genotype listed first Cp = Dorothy Chapman Ln = Priscilla Lane Mk = Judith Mackensen So = Janice Southard |
