Phenotypes associated with this allele

• Allele Symbol: Spaar^em1Ppp
• Allele Name: endonuclease-mediated mutation 1, Pier Paolo Pandolfi
• Allele ID: MGI:6343396
• Summary: 1 genotype

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Spaar^em1Ppp/Spaar^em1Ppp	C57BL/6J-Spaar^em1Ppp	MGI:6782383

Genotype
MGI:6782383

hm1

• Allelic Composition: Spaar^em1Ppp/Spaar^em1Ppp
• Genetic Background: C57BL/6J-Spaar^em1Ppp

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

muscle

abnormal muscle physiology ( J:238474 )

• 4 days after cardiotoxin (CTX) administration, tibialis anterior (TA) muscle from mutant mice fed a control diet shows increased phosphorylation of S6K and S6, with a significantly higher phospho-S6K to total S6K ratio (reflecting hyperactivation of mTORC1), relative to TA muscle from similarly fed wild-type controls

• however, in the setting of a leucine-free diet, mutant mice show inhibition of mTORC1 activation with no differences in the pS6K/S6K ratio in TA muscle relative to leucine-deprived wild-type controls

enhanced muscle regeneration ( J:238474 )

• 7 days after CTX administration, injured TA muscle from mutant mice fed a control diet shows increased regenerative capacity with a marked % change in regenerating TA weight and an increased number of larger regenerating myofibers with centrally located nuclei, relative to TA muscle from similarly fed wild-type controls

• 4 days after CTX administration, injured TA from mutant mice fed a control diet shows increased numbers of Pax7+ and Myog+ cells and a higher % of Pax7+/Ki67+ cells than TA from similarly fed wild-type controls, indicating increased stem cell proliferation

• 14 days after CTX administration, injured TA from mutant mice fed a control diet shows a higher % of mature cells with peripheral nuclei relative to TA from similarly fed wild-type controls, indicating faster myofiber maturation during regeneration

• however, in the setting of a leucine-free diet, mutant mice fail to efficiently regenerate muscle with no significant differences in % change in TA weight relative to leucine-deprived wild-type controls

growth/size/body

growth/size/body region phenotype ( J:238474 )

N • unchallenged mice appear grossly normal and exhibit normal body weight in both sexes up to 8 weeks of age