Phenotypes Associated with This Genotype

Genotype
MGI:5492109

• Allelic Composition: Nf1^tm1Par/Nf1^tm1Par; Tg(Prrx1-cre)1Cjt/0
• Genetic Background: involves: 129S1/Sv * 129X1/SvJ * C57BL/6J * SJL/J

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

growth/size/body

decreased body weight ( J:173779 )

• weight is on average reduced by 25%

limbs/digits/tail

short limbs ( J:173779 )

• short-limbed dwarfism, with mutants showing a reduction in entire limb size

muscle

abnormal muscle morphology ( J:173779 )

• 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

abnormal muscle development ( J:173779 )

• 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

abnormal myogenesis ( J:173779 )

• defect in myogenesis affecting the terminal differentiation of myoblasts between E12.5 and E14.5

abnormal myoblast differentiation ( J:173779 )

• maker analysis indicates a severe disruption of myoblast terminal differentiation

increased myoblast proliferation ( J:173779 )

• 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

abnormal muscle fiber morphology ( J:173779 )

• 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

decreased skeletal muscle fiber number ( J:173779 )

• total number of muscle fibers is reduced by 50% in the triceps

decreased muscle weight ( J:173779 )

• weight of triceps muscle is reduced by more than 50%

decreased skeletal muscle mass ( J:173779 )

• reduction in muscle size and mass

skeletal muscle fibrosis ( J:173779 )

• generalized muscle fibrosis, characterized by expansion of collagen-rich connective tissue, and reduction in total number of muscle fibers

abnormal muscle physiology ( J:173779 )

• 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

abnormal myoblast differentiation ( J:173779 )

• maker analysis indicates a severe disruption of myoblast terminal differentiation

increased myoblast proliferation ( J:173779 )

• 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		DO ID	OMIM ID(s)	Ref(s)
neurofibromatosis 1		DOID:0111253	OMIM:162200	J:173779