Phenotypes for Lmna MGI:2177931 MGI Mouse

mortality/aging

premature death ( J:58702 )

• all die by 8 weeks of age

cellular

abnormal cell nucleus morphology ( J:58702 )

• in MEFs, nuclei appear elongated or irregular with loss of B-type lamins from 1 pole, slight clustering of nuclear pore complexes, and loss of emerin from the nuclear envelope into the cytoplasm

• in MEFs and hepatocytes, patchy thinning or loss of heterochromatin from the nuclear face of the inner nuclear membrane is seen and these regions also lack identifiable nuclear pore complexes

• the nuclear envelope is more easily fragmented during isolation

growth/size/body

decreased body weight ( J:58702 )

• at 4 weeks, mean body weight is about 50% of wild-type and heterozygous littermates

postnatal growth retardation ( J:58702 )

• growth retardation is seen by 2-3 weeks of age and growth ceases by 4 weeks of age

muscle

dystrophic muscle ( J:58702 )

• muscles surrounding the femur and perivertebral muscles are dystrophic while cardiac muscle is variably affected with ventricular muscle more severely impaired; however, muscles in the head, tongue and diaphragm are relatively normal

• muscle fibers are variably affected with those closer to the bone being more severely impaired

• no elevation of serum creatine kinase levels are detected

muscle degeneration ( J:58702 )

• in the heart, some ventricular myocytes show signs of degeneration often associated with patchy mineralization

behavior/neurological

decreased grip strength ( J:58702 )

• at 3-4 weeks mice have reduced grip strength

abnormal gait ( J:58702 )

• at 3-4 weeks mice display a stiff walking posture with splayed hind legs

skeleton

kyphoscoliosis ( J:58702 )

• progressive kyphoscoliosis starting around 3-4 weeks of age

adipose tissue

decreased white adipose tissue amount ( J:58702 )

• absence of white fat

nervous system

abnormal axon morphology ( J:75378 )

• sciatic nerve axon density is reduced, axon diameter is increased, and nonmyelinated axons are present

abnormal sciatic nerve morphology ( J:75378 )

• sciatic nerve axon density is reduced, axon diameter is increased, and nonmyelinated axons are presen

abnormal myelination ( J:75378 )

• nonmyelinated axons are present in the sciatic nerve

immune system

thymus atrophy ( J:58702 )