Mice that are homozygous for the targeted mutation are viable and fertile. Homozygous males exhibit decreased body weight on a standard chow diet; weight gain in females is comparable to controls. On a 55% fat diet, both males and females remain lean. Although adipocyte cell number is not decreased, adipocyte volume is significantly decreased. Basal metabolic rate and total energy expenditure are increased in male homozygotes on high fat diet. Additionally, male homozygous mice exhibit decreased leptin levels, increased insulin sensitivity as a result of increased glucose utilization in skeletal muscle and enhanced glucose tolerance.


Heterozygous males exhibit decreased body weight on a standard chow diet; however, on a 55% fat diet weight gain is similar to wild-type. Leptin levels are decreased in heterozygous males on both chow and high-fat diets.

This mutant mouse strain may be useful in studies of energy regulation, diet-induced obesity and glucose metabolism. 
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.

These Ptpn1 (protein tyrosine phosphatase) knockout mice remain lean on a high fat diet, exhibit a decrease in adipocyte volume, increased glucose utilization and enhanced glucose tolerance. This mutant mouse strain may be useful in studies of energy regulation, diet-induced obesity and glucose metabolism.

This strain is hosted by NIH's MMRRC, which partners with JAX for the distribution of this and other strains. For additional information and to purchase, please visit the MMRRC site.