Deficient peripheral myelin (Dpmy) heterozygotes can be identified by a whole body tremor by approximately 3 weeks of age. The gait is fairly normal and the fast overall tremor persists when heterozgyotes are picked up. Heterozgyotes become hunched and sickly by approximately five to nine months of age. Histology on Two female and one male mutant at eleven weeks of age found an absence of peripheral myelin and neurogenic atrophy of some muscle fibers. Of twenty-nine pups born in six litters from wild-type x heterozygote or heterozygote x wild-type crosses, ten were phenotypically identified as mutant at three weeks of age and six were missing before phenotypic assessment. Both heterozygous females and males can breed, although a higher than normal number are not productive breeders.
The deficient peripheral myelin (dpmy) mutation arose spontaneously in CBA/J. This mutation was outcrossed to C57BL/6NJ and sperm was frozen from heterozygous males. Cryorecovery with CBA/J oocytes has proven successful.
Because of the phenotype it is best for the care of these mutants to add nestlets and crushed grain in the bottom of the housing unit. Although both males and females have successfully bred, there is a higher than normal number of non-productive breeders.
When using the B6NJ;CBA-Dpmy/GrsrJ mouse strain in a publication, please cite the originating article(s) and include JAX stock #027183 in your Materials and Methods section.