Mouse Genome Informatics
cn
    Nf1tm1Par/Nf1tm1Par
Tg(Prrx1-cre)1Cjt/0

involves: 129S1/Sv * 129X1/SvJ * C57BL/6J * SJL/J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
       
growth/size
• weight is on average reduced by 25%

limbs/digits/tail
• short-limbed dwarfism, with mutants showing a reduction in entire limb size

muscle
• mutants exhibit muscle dystrophy
• large areas of dystrophic musculature are occupied by fat tissue
• muscle connective tissue shows increased proliferation at E14.5 and an increase in connective tissue in muscles is already seen at E16.5
• muscle fibers are thinned out at E16.5
• marker analysis indicates a defect in muscle formation at E13.5, with specific muscle primordial reduced in size or entirely missing; approximate 30% reduction in the m. triceps size and about 50% reduction in the m. gluteus maximus size of E13.5 embryos
• the m. latissimus dorsi appears smaller and shows rarefaction of muscle fibers
• distal muscle groups in the extremities are most affected, with some muscles completely missing, indicating that the muscle differentiation process is disturbed
• defect in myogenesis affecting the terminal differentiation of myoblasts between E12.5 and E14.5
• maker analysis indicates a severe disruption of myoblast terminal differentiation
• marker analysis indicates that migration and proliferation of pre-muscle cells at E11.5 are normal but increased proliferation of myoblasts in ventral muscle masses is seen
• muscles show a 20% increase in the number of fibers with cleft-like invaginations (split fibers)
• muscle fiber size appears more variable than in controls, however no overt muscle regeneration is seen
• total number of muscle fibers is reduced by 50% in the triceps
• weight of triceps muscle is reduced by more than 50%
• reduction in muscle size and mass
• generalized muscle fibrosis, characterized by expansion of collagen-rich connective tissue, and reduction in total number of muscle fibers
• in the force gauge pull test, mice show a dramatic reduction in muscle force
• satellite cells exhibit normal self-renewal but impaired differentiation as indicated by diminished myotube formatio

cellular
• maker analysis indicates a severe disruption of myoblast terminal differentiation
• marker analysis indicates that migration and proliferation of pre-muscle cells at E11.5 are normal but increased proliferation of myoblasts in ventral muscle masses is seen

Mouse Models of Human Disease
OMIM IDRef(s)
Neurofibromatosis, Type I; NF1 162200 J:173779