| First Author | Lyon MF | Year | 1989 |
| Journal | Mouse News Lett | Volume | 83 |
| Pages | 158-159 | Mgi Jnum | J:14234 |
| Mgi Id | MGI:62406 | Citation | Lyon MF, et al. (1989) Extra-toes spotting, a new polydactyly mutation. Mouse News Lett 83:158-159 |
| abstractText | Full text of MNL contribution: Research News: 2. Extra-toes spotting. a new polydactyly mutation. An animal with a white belly spot and preaxial polydactyly of the forefeet was found among the offspring of a male treated with 250 mg/kg ethylnitrosourea. Mapping studies have shown that the phenotype is due to a new locus on chromosome 7, and the name and symbol extra-toes spotting, Xs, have been given. The mutation is dominant, and affected animals have one or more extra digits preaxially on one or both forefeet. The left forefoot is affected more frequently than the right. The hind feet are often completely normal but occasionally the first digit of one or both hind feet may be thickened, twisted or duplicated. Some but not all animals have white spotting, usually on the belly but sometimes on the head. The amount varies limb defects including absence of major bones, and occasionally the pinna is abnormal. In some crosses the proportion of abnormal animals falls below Mendelian expectation, and this may be due to reduced penetrance, or viability, or both. The map position has been found from separate crosses to cch and p. In backcrosses of Xs +/+ cch x + cch/+ cch offspring were: Xs + , 24, + cch, 92, Xs cch, 10, + + , 57, RF 67/183 or 36.6 +/- 3.6%. Backcrosses of Xs +/+ p x + p/+ p gave: Xs +, 43, + p, 61, Xs p, 10, + +, 24, RF 34/138 or 24.6 +/- 3.7%. It is concluded that the order of loci is XS-p-cch. Multipoint tests are in progress. (Lyon and Glenister). |
