The Observation of Rolling Mouse Nagoya (rol), a New Neurological Mutant, and its Maintenance

Abstract

A mutant was found in the course of mating experiments between S III, which was characterized by suckling death, and C57BL/6JNga. The symptoms of this are creeping or rolling in a poor motor control of hind limbs, and sometimes, mutant a stiff of hind legs and tail, and recognized from 10 to 14 days after birth. In genetical studies, the mutant is considered to be controlled by a single autosomal recessive gene. The symbol of this gene is proposed as “rol” based on the rolling mouse Nagoya. The rolling mouse is conjèctured to have a cerebellum abnormarity and may be used as a model animal in biomedical fields. The rolling female is fertile but low in ability of breeding and nursing‘ compared with a normal stanard female, and the male is almost infertile because of a bad coition. Rolling mice born in the inbreeding line are weak, but segregated rolling mice from cross breeding are stable in viability compared with one in the inbreeding line. Based on these conditions, the breeding system of this mutant strain was planned to maintain the mutant gene and also to produce more rolling mice. In this case, animals for maintenance, for production and for experiment must be considered to distinct clearly. So the cross-intercross system with rotational crossing using the rolling female is proposed for maintenance of the“rol”gene, or the nucleus of this mutant strain. In this mating system, the heterosis is effective in prevention of inbreeding depretion. It is advisable to make congenic strains or coisogenic strains for production, and to produce rolling mice for experiment from these strains.