• all die by 8 weeks of age

• 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

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

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

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

• 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

• at 3-4 weeks mice have reduced grip strength

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

• progressive kyphoscoliosis starting around 3-4 weeks of age

• absence of white fat

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

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

• nonmyelinated axons are present in the sciatic nerve

• probably secondary to physiological stress

• probably secondary to physiological stress

• probably secondary to physiological stress

• probably secondary to physiological stress

• die by 4-6 weeks of age

• spermatids and spermatozoa are largely absent (J:88595)

• increased frequency of leptotene and zygotene spermatocytes and decreased frequency of pachytene and diplotene spermatocytes resulting from arrest and apoptosis of spermatocytes during the pachytene stage (J:88595)

• however, oogenesis in females is normal (J:88595)

• unpaired chromosomes and/or improperly paired sex chromosomes and failure to progress through prophase I are seen (J:88595)

• at 4 weeks serum glucose levels are decreased however insulin levels are only slightly and not significantly decreased

• only significant in 4 week old females although levels in males also tend to be lower

• in many MEFs, nuclei appear elongated but distribution of nuclear envelope proteins is normal except for increased levels of cytoplasmic emerin

• on a high fat diet, females develop mild insulin resistance that correlates with increased body weight, no insulin resistance is seen in males

• on a normal diet, serum glucose, insulin, and triglyceride levels are normal, insulin sensitivity and glucose tolerance

• on a high fat diet, females develop increased insulin but not glucose levels

• no signs of lipoatrophy are seen (J:75101)

• liver morphology is normal (J:75101)

• mice die between 10 and 14 weeks of age

• mice develop fractures in the extremities by 8 weeks of age

• misshapen

• viable and fertile with normal growth and muscle strength

• no bone fractures or other skeletal abnormalities are seen (J:95274)

• normal nuclear envelope morphology in MEFs (J:95274)

• improved growth compared to mice homozygous for Zmpste24^tm1Sgy only (J:95274)

• muscle strength is similar to wild-type (J:95274)

• die by 4-6 weeks of age

• die by 4-6 weeks of age