Mice homozygous for the diabetes 3J spontaneous mutation (Leprdb-3J) become identifiably obese around three to four weeks of age. Elevations of plasma insulin begin at 10 to 14 days and of blood sugar at four to eight weeks. Homozygous mutant mice are polyphagic, polydipsic, and polyuric. The course of the disease is markedly influenced by genetic background. Homozygous mutant mice on the 129P3/J background exhibit severe obesity but the diabetes phenotype is much reduced.
|Allele Name||diabetes 3 Jackson|
|Gene Symbol and Name||Lepr, leptin receptor|
|Strain of Origin||129P3/J|
|Molecular Note||Sequence analysis of the 3J allele revealed a 17 nucleotide deletion beginning at base 1874. This deletion results in a shift of the reading frame, and a premature termination of the protein at the 11th amino acid after the deletion site. The mutation is predicted to result in a truncated receptor without a transmembrane domain and affects all Lepr splice variants.|