Phenotypes associated with this allele

• Allele Symbol: Msc^tm1Eno
• Allele Name: targeted mutation 1, Eric N Olson
• Allele ID: MGI:3655692
• Summary: 4 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Msc^tm1Eno/Msc^tm1Eno	involves: 129	MGI:3655695
cx2	Msc^tm1Eno/Msc^tm1Eno Tcf21^tm2Eno/Tcf21^tm2Eno	involves: 129 * Black Swiss	MGI:3655699
cx3	Msc^tm1Eno/Msc^+ Tcf21^tm2Eno/Tcf21^tm2Eno	involves: 129 * Black Swiss	MGI:3655867
cx4	Msc^tm1Eno/Msc^tm1Eno Tcf21^tm2Eno/Tcf21^+	involves: 129 * Black Swiss	MGI:3655869

Genotype
MGI:3655695

hm1

• Allelic Composition: Msc^tm1Eno/Msc^tm1Eno
• Genetic Background: involves: 129

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

normal phenotype

no abnormal phenotype detected ( J:111337 )

• homozygotes are obtained at the expected Mendelian ratios and show no obvious abnormalities

Genotype
MGI:3655699

cx2

• Allelic Composition: Msc^tm1Eno/Msc^tm1Eno; Tcf21^tm2Eno/Tcf21^tm2Eno
• Genetic Background: involves: 129 * Black Swiss

mortality/aging

neonatal lethality, complete penetrance ( J:111337 )

• double homozygotes are born alive, but similar to single Tcf21^tm2Eno homozygotes, they die within minutes after birth

muscle

abnormal masticatory muscle morphology ( J:111337 )

• most double homozygotes show a complete absence of the major muscles of mastication, not observed in either single homozygote

absent masseter muscle ( J:111337 )

• most double homozygotes show a complete absence of the masseter muscle

abnormal pterygoid muscle morphology ( J:111337 )

• atrophic pterygoid myofibers are found to persist unilaterally in a subset of double homozygotes

absent pterygoid muscle ( J:111337 )

• most double homozygotes show a complete absence of the medial and lateral pterygoid muscles

absent temporalis muscle ( J:111337 )

• most double homozygotes show a complete absence of the temporalis muscle

abnormal myogenesis ( J:111337 )

• at E10.5, TUNEL labeling indicates that first branchial arch muscle precursor cells undergo apoptosis resulting in ablation of masticatory muscles

• notably, other first arch-derived muscles, e.g. the anterior digastric and mylohyoid, which do not function in mastication, are present and trunk muscles appear unaffected

diaphragmatic hernia ( J:111337 )

• double homozygotes exhibit diaphragmatic hernia with visceral organs being displaced into the chest

craniofacial

abnormal masticatory muscle morphology ( J:111337 )

• most double homozygotes show a complete absence of the major muscles of mastication, not observed in either single homozygote

absent masseter muscle ( J:111337 )

• most double homozygotes show a complete absence of the masseter muscle

abnormal pterygoid muscle morphology ( J:111337 )

• atrophic pterygoid myofibers are found to persist unilaterally in a subset of double homozygotes

absent pterygoid muscle ( J:111337 )

• most double homozygotes show a complete absence of the medial and lateral pterygoid muscles

absent temporalis muscle ( J:111337 )

• most double homozygotes show a complete absence of the temporalis muscle

cleft secondary palate ( J:111337 )

• double homozygotes exhibit cleft palate

abnormal palatal shelf elevation ( J:111337 )

• palatal shelves do not elevate or elevate unilaterally (Fig. 3c)

digestive/alimentary system

cleft secondary palate ( J:111337 )

• double homozygotes exhibit cleft palate

abnormal palatal shelf elevation ( J:111337 )

• palatal shelves do not elevate or elevate unilaterally (Fig. 3c)

growth/size/body

abnormal masticatory muscle morphology ( J:111337 )

• most double homozygotes show a complete absence of the major muscles of mastication, not observed in either single homozygote

absent masseter muscle ( J:111337 )

• most double homozygotes show a complete absence of the masseter muscle

abnormal pterygoid muscle morphology ( J:111337 )

• atrophic pterygoid myofibers are found to persist unilaterally in a subset of double homozygotes

absent pterygoid muscle ( J:111337 )

• most double homozygotes show a complete absence of the medial and lateral pterygoid muscles

absent temporalis muscle ( J:111337 )

• most double homozygotes show a complete absence of the temporalis muscle

cleft secondary palate ( J:111337 )

• double homozygotes exhibit cleft palate

abnormal palatal shelf elevation ( J:111337 )

• palatal shelves do not elevate or elevate unilaterally (Fig. 3c)

Genotype
MGI:3655867

cx3

• Allelic Composition: Msc^tm1Eno/Msc⁺; Tcf21^tm2Eno/Tcf21^tm2Eno
• Genetic Background: involves: 129 * Black Swiss

muscle

muscle phenotype ( J:111337 )

N • unlike double homozygotes, mice heterozygous for Msc^tm1Eno and homozygous for Tcf21^tm2Eno exhibit no morphological defects in first branchial arch-derived masticatory skeletal muscles

Genotype
MGI:3655869

cx4

• Allelic Composition: Msc^tm1Eno/Msc^tm1Eno; Tcf21^tm2Eno/Tcf21⁺
• Genetic Background: involves: 129 * Black Swiss

normal phenotype

no abnormal phenotype detected ( J:111337 )

• unlike double homozygotes, mice homozygous for Msc^tm1Eno and heterozygous for Tcf21^tm2Eno are viable and exhibit no morphological defects in first branchial arch-derived masticatory skeletal muscles