| First Author | Wallace ME | Year | 1987 |
| Journal | Mouse News Lett | Volume | 78 |
| Pages | 40 | Mgi Jnum | J:14122 |
| Mgi Id | MGI:62298 | Citation | Wallace ME (1987) Paraparesis-lethal, pl. Mouse News Lett 78:40 |
| abstractText | Full text of MNL contribution: Paraparesis-lethal, pi. This recessive arose in two sibmatings made from one parental mating, in Peru-Coppock mice descended from site 47: the sibmatings were generation 18, and one male from one sibmating and one female from the other were noticed to be affected. Several matings were made between sibs of the affected mice but only one segregated. Litters from all matings were observed at birth and several times again until the affected mice died. The segregating mating produced 17 normal and 6 affected mice, with no sex-bias. The fit to 3: 1 is good, indicating full penetrance and viability within the Peru genome. Affected mice could not abduct their hind legs, fell behind their sibs in weight and did not do better on fostering. They died at various ages up to 14 days. A heterozygote was outcrossed to three laboratory stocks (line 2, line 4 and CBA/FaCam), and many intercrosses made from them, but the condition did not reappear. This suggests that in the mixed background it had become antenatally lethal. It is now extinct. Its disappearance was unexpected and no investigation was made on the 6 which survived birth to determine whether the deformity was in the pelvis (skeletal) or due to neurological or muscular deficiency; hence the descriptive name. The F2 from the crosses to lines 2 and 4 segregated in several laboratory mutants, whose single-factor ratios were examined for signs of disturbance due to lethality of the homozygous normal on account of close linkage with the pi locus: lack of disturbance suggests that pi is not closely linked with Sd, A, Ca, Hm or eSo. |
