Phenotypes Associated with This Genotype

Genotype
MGI:4943736

• Allelic Composition: Lrp1^tm2Her/Lrp1^tm2Her; Tg(Fabp4-cre)1Rev/0
• Genetic Background: involves: 129S7/SvEvBrd * C57BL/6

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

adipose tissue

abnormal adipose tissue amount ( J:127398 )

decreased brown adipose tissue amount ( J:127398 )

• reduced by more than 65% compared to controls

decreased total body fat amount ( J:127398 )

• difference in body weight is entirely due to the decrease in fat mass

• due to a macroscopically obvious decrease in the interscapular and epididymal fat pads

• increase in fat mass loss when fasted for 24 h

abnormal brown fat cell morphology ( J:127398 )

decreased brown fat cell size ( J:127398 )

decreased brown fat lipid droplet number ( J:127398 )

decreased white fat cell size ( J:127398 )

abnormal fat pad morphology ( J:127398 )

decreased epididymal fat pad weight ( J:127398 )

decreased interscapular fat pad weight ( J:127398 )

abnormal adipose tissue physiology ( J:127398 )

• dramatic decrease in uptake of lipids by adipocytes

• decrease is more dramatic in brown adipose tissue compared to white adipose tissue

growth/size/body

decreased body weight ( J:127398 )

decreased susceptibility to diet-induced obesity ( J:127398 )

• when placed on a high fat diet

increased susceptibility to weight loss ( J:127398 )

• increase in fat mass loss when fasted for 24 h

homeostasis/metabolism

homeostasis/metabolism phenotype ( J:127398 )

N • no difference in respiratory quotients is detected compared to controls

impaired adaptive thermogenesis ( J:127398 )

• core temperature decreases faster when the ambient temperature is lowered compared to similarly exposed controls

decreased circulating leptin level ( J:127398 )

• consistent with the decrease in total body fat amount

decreased body surface temperature ( J:127398 )

• at 22 degrees C core temperature is similar to controls but surface temperature is reduced

• the difference in surface temperature compared to controls becomes more pronounced at 4 degrees C

abnormal body temperature homeostasis ( J:127398 )

• behavioral signs (shivering and trunk curl) indicate impaired ability to maintain body temperature

increased energy expenditure ( J:127398 )

• on normal chow and high fat diets

decreased susceptibility to diet-induced obesity ( J:127398 )

• when placed on a high fat diet

increased oxygen consumption ( J:127398 )

abnormal glucose homeostasis ( J:127398 )

decreased circulating glucose level ( J:127398 )

• markedly lower fasting glucose levels

• fasting glucose levels do not increase even after 16 weeks on a high fat diet

decreased circulating insulin level ( J:127398 )

• markedly lower fasting insulin levels

• fasting insulin levels do not increase even after 16 weeks on a high fat diet

improved glucose tolerance ( J:127398 )

• results indicate that skeletal muscle is responsible for the elevated plasma glucose clearance

abnormal lipid homeostasis ( J:127398 )

abnormal circulating lipid level ( J:127398 )

• postprandial lipid clearance from the circulation in response to a bolus fat load is markedly delayed

decreased circulating free fatty acids level ( J:127398 )

• markedly lower fasting non-esterified fatty acids levels

decreased liver triglyceride level ( J:127398 )

behavior/neurological

increased food intake ( J:127398 )

• despite weighing less, mice consume more food compared to controls

trunk curl ( J:127398 )

• body surface reduction by coiling up that is visible at room temperature (22 degrees C) but becomes more pronounced at 4 degrees C

muscle

increased skeletal muscle cell glucose uptake ( J:127398 )

• enhanced skeletal muscle glucose uptake consistent with the increased muscle activity is seen

liver/biliary system

decreased liver triglyceride level ( J:127398 )

cellular

increased skeletal muscle cell glucose uptake ( J:127398 )

• enhanced skeletal muscle glucose uptake consistent with the increased muscle activity is seen