mammalian phenotype

• reproductive system phenotype
  • Normal - mice are fertile and show no abnormalities pertaining to spermatogenesis or sperm motility
  (MGI Ref ID J:85762)

endocrine/exocrine gland phenotype

• decreased insulin secretion
  • total insulin secreted by isolated islets of Langerhans in response to glucose stimulation is 56% that of wild-type islets
  (MGI Ref ID J:125307)

liver/biliary system phenotype

• decreased susceptibility to hepatic steatosis
  • when fed a high fat diet
  (MGI Ref ID J:125307)

mammalian phenotype

• behavior/neurological phenotype
  • Normal - despite increased metabolism and resistance to diet induce obesity, no differences in locomotor activity or food intake are detected
  (MGI Ref ID J:125307)

• endocrine/exocrine gland phenotype
  • Normal - despite defects in glucose-stimulated insulin secretion, no defects are detected in islet of Langerhans morphology, size or beta-cell area and no differences in total pancreatic insulin levels are seen
  (MGI Ref ID J:125307)

muscle phenotype

• abnormal muscle physiology
  • permeabilized soleus muscle fibers show elevated ATP production from succinate
  (MGI Ref ID J:125307)
  • Normal - however, no difference in mitochondrial number or area are detected in soleus muscles
  (MGI Ref ID J:125307)

growth/size/body region phenotype

• decreased susceptibility to diet-induced obesity
  • when fed a high fat diet
  (MGI Ref ID J:125307)

nervous system phenotype

• abnormal nervous system physiology
  • females have higher tyrosine hydroxylase activity in the pontine (A5 and A6) and medullary (A2C2 and A1C1) brain stem catecholaminergic cell groups compared to sex matched controls
  (MGI Ref ID J:139216)
  • males have lower tyrosine hydroxylase activity in the pontine (A5 and A6) and medullary (A2C2) brain stem catecholaminergic cell groups compared to sex matched controls
  (MGI Ref ID J:139216)

respiratory system phenotype

• abnormal pulmonary ventilation
  • hypoxic ventilatory response (HVR) is increased in females throughout exposure to 10% or 8% O2 relative to controls
  (MGI Ref ID J:139216)
  • in males HVR is increased relative to controls only during the first minute of exposure to 8% O2
  (MGI Ref ID J:139216)
  • females show impaired ventilatory acclimatization following exposure to acute hypoxia
  (MGI Ref ID J:139216)
  • hypoxic ventilatory decline is slower in males at 8% and in females at 8% and 10% O2 relative to sex-matched controls
  (MGI Ref ID J:139216)

homeostasis/metabolism phenotype

• abnormal glucose homeostasis
  (MGI Ref ID J:125307)

• decreased insulin secretion
  • total insulin secreted by isolated islets of Langerhans in response to glucose stimulation is 56% that of wild-type islets
  (MGI Ref ID J:125307)

• increased oxygen consumption
  (MGI Ref ID J:125307)

• abnormal metabolism
  • produce more CO2 and heat
  (MGI Ref ID J:125307)

• abnormal respiratory quotient
  • respiratory quotient indicates a slight substrate preference for carbohydrate over fat
  (MGI Ref ID J:125307)

• decreased circulating insulin level
  • when fed a high fat diet, fasting insulin levels are significantly lower than in controls
  (MGI Ref ID J:125307)
  • insulin levels are modestly but significantly lower at 5 and 45 minutes after a glucose injection
  (MGI Ref ID J:125307)

• decreased susceptibility to diet-induced obesity
  • when fed a high fat diet
  (MGI Ref ID J:125307)

• improved glucose tolerance
  • Normal - however, on a standard diet there is no significant difference in glucose tolerance in mutants compared to wild-type mice
  (MGI Ref ID J:125307)
  • when fed a high fat diet mice do not develop glucose intolerance unlike wild-type mice
  (MGI Ref ID J:125307)

• increased insulin sensitivity
  • Normal - however, on a standard diet there is no significant difference in insulin sensitivity in mutants compared to wild-type mice
  (MGI Ref ID J:125307)
  • when fed a high fat diet mice do not develop insulin resistance unlike wild-type mice
  (MGI Ref ID J:125307)