T^c, curtailed, semidominant. Found among offspring from a cross between a multiple recessive testing stock, T stock, and a pup from an irradiated C3H/HeH female that had been impregnated by a 101/H male. Heterozygotes have complete or near-complete absence of the tail, absence of the odontoid process of the axis, absence of the nucleus pulposi of the intervertebral discs, a tendency for rib and vertebral fusions, and a slight decrease in average number of presacral vertebrae. They occasionally show paralysis of the hindlimbs and atresia ani. Homozygotes die at the same time as T/T embryos and are similar to them but more severely affected. T^c/T embryos are variable and intermediate between T/T and T ^c/T ^c (J:5003).