| First Author | Hummel KP | Year | 1974 |
| Journal | Mouse News Lett | Volume | 50 |
| Pages | 43 | Mgi Jnum | J:13651 |
| Mgi Id | MGI:61833 | Citation | Hummel KP, et al. (1974) fat = fat, Chr UN. Mouse News Lett 50:43 |
| abstractText | Full text of MNL contribution: New Mutants: 1. A new fat mutant, proposed symbol fat, appeared recently in strain HRS/J. Twenty-five of 110 offspring (23% from heterozygous parents were classified as fat/fat, indicating the mutation to be recessive. Matings of +/fat males and females with +/ob and +/db females and males indicate that fat is not allelic with either the phenotypically similar obese or diabetes genes. Thirty-three offspring of +/fat by +/ob matings, and 34 offspring from +/fat by +/db matings were all classified as normal. Homozygotes are recognizable at 4 to 5 weeks of age by deposition of abnormal amounts of fat. They become fatter with age, often weighing 60 grams by 6 months and are hyperinsulinemic throughout life. Diabetic symptoms such as polyuria and glycosuria have not been observed although fluctuations in blood sugar concentrations occur. Hyperglycemia with blood sugar concentrations as high as 300 mg/100 ml is infrequent, while hypoglycemia with blood sugar less than 100 mg/100 ml is common in animals older than 6 months. Preliminary morphological studies of pancreatic islets show moderate increases in number and size of islets with some degranulation of .beta cells. Studies comparing the obesity syndrome caused by this gene and those caused by the genes diabetes and obese will be undertaken after fat has been placed on C57BL/6J and C57BL/KsJ backgrounds. (Hummel and Coleman) |
