| Primary Identifier | MGI:1856160 | Allele Type | Spontaneous |
| Gene | Mbp | Inheritance Mode | Recessive |
| Strain of Origin | MDB/Dt | Is Recombinase | false |
| Is Wild Type | false |
| description | The Mbpshi-mld mutation arose spontaneously in the MDB/Dt strain at Purdue University (J:5917). Two stocks of Mbpshi-mld-bearing mice, both derived from the Purdue original stock at about the same time, and maintained respectively in Worcester, Massachusetts, and in Lausanne, Switzerland, show quantitative differences in life span, in incidence of convulsions, in MBP at older ages, and in proportion of optic axons myelinated. The differences are attributed to differences in regulatory genes in the two stocks, maintained on quite different backgrounds (J:27485). The effects of the Mbpshi-mld mutation are less severe than those of Mbpshi. MBP is present in the CNS, though low in quantity, and the myelin deficient phenotype is rendered normal by an Mbp transgene (J:6320). Mbpshi/Mbpshi-mld heterozygotes are deficient in CNS myelin to a greater extent than Mbpshi-mld/Mbpshi-mld homozygotes, but less than Mbpshi/Mbpshi homozygotes (J:27481). Mbpshi-mld mice have normal lipid/protein ratios, lipid distribution patterns, and only moderate abnormalities of fatty acid profiles (J:27484), whereas these elements are strongly abnormal in Mbpshi (J:6012). Mbpshi caused more severe deficits in learning performance than Mbpshi-mld, while neither affected natural behavior (J:27482). |
| molecularNote | This mutation comprises a tandem duplication and inversion of Mbp. Recombination points indicate that the duplication and inversion event was the result of nonhomologous recombination. Antisense RNA produced by the duplicated gene complexes with sense RNA reducing Mpb expression. |
