Phenotypes associated with this allele

• Allele Symbol: Twsg1^tm1.1Mboc
• Allele Name: targeted mutation 1.1, Michael B O'Connor
• Allele ID: MGI:3830633
• Summary: 6 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc	129S/SvEv-Twsg1^tm1.1Mboc	MGI:3830683
hm2	Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc	B6.129S7-Twsg1^tm1.1Mboc	MGI:3830684
hm3	Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc	involves: 129S7/SvEvBrd * C57BL/6 * FVB/N	MGI:3830682
cx4	Trp53^tm1Brd/Trp53^tm1Brd Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc	involves: 129S7/SvEvBrd * C57BL/6	MGI:5056121
cx5	Bmp4^tm2Blh/Bmp4^+ Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc	involves: 129S/SvEv * C57BL/6 * FVB/N	MGI:3830686
cx6	Chrd^tm1Emdr/Chrd^tm1Emdr Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc	involves: 129/Sv * C57BL/6 * FVB/N	MGI:3830685

Genotype
MGI:3830683

hm1

• Allelic Composition: Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc
• Genetic Background: 129S/SvEv-Twsg1^tm1.1Mboc

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

mortality/aging

lethality at weaning, incomplete penetrance ( J:88784 )

• Background Sensitivity: 12% lethality at weaning 12% lethality at weaning

neonatal lethality, incomplete penetrance ( J:88784 )

• Background Sensitivity: 18% lethality at birth

growth/size/body

decreased body size ( J:88784 )

decreased body weight ( J:88784 )

• Background Sensitivity: growth defect more pronounced than on a mixed background

skeleton

abnormal jaw morphology ( J:88784 )

• a reduced jaw is frequently seen

abnormal vertebral arch morphology ( J:88784 )

• neural arch defects

craniofacial

abnormal craniofacial morphology ( J:88784 )

abnormal jaw morphology ( J:88784 )

• a reduced jaw is frequently seen

Genotype
MGI:3830684

hm2

• Allelic Composition: Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc
• Genetic Background: B6.129S7-Twsg1^tm1.1Mboc

mortality/aging

postnatal lethality, complete penetrance ( J:88784 )

• Background Sensitivity: 18% survive perinatal period but are dead by weaning

perinatal lethality, incomplete penetrance ( J:88784 )

• Background Sensitivity: high degree of perinatal lethality

• Background Sensitivity: 38% without showing any gross abnormalities

• Background Sensitivity: 44% with various craniofacial defects

skeleton

agnathia ( J:88784 )

• 20% of neonates with agnathia and no other midline defects

abnormal cervical vertebrae morphology ( J:88784 )

• abnormalities of cervical vertebrae

• axial skeleton otherwise normal

craniofacial

abnormal craniofacial morphology ( J:88784 )

• craniofacial features vary from normal to severe rostral truncations

agnathia ( J:88784 )

• 20% of neonates with agnathia and no other midline defects

abnormal craniofacial development ( J:88784 )

• 70% with midline defects

• cyclopia or synophthalmia

• long nasal process above the eye field

• single nostril combined with agnathia

fused first pharyngeal arch ( J:88784 )

• remains fused in the midline at E9.5

decreased mouth size ( J:144153 )

single external naris ( J:88784 )

• single nostril often seen in association with agnathia and various eye defects

lowered ear position ( J:144153 )

vision/eye

cyclopia ( J:88784 )

• frequently

microphthalmia ( J:88784 )

• often seen in association with single nostril and agnathia

anophthalmia ( J:88784 )

• often seen in association with single nostril and agnathia

respiratory system

single external naris ( J:88784 )

• single nostril often seen in association with agnathia and various eye defects

hearing/vestibular/ear

lowered ear position ( J:144153 )

digestive/alimentary system

abnormal submandibular gland development ( J:144153 )

• normal when the mandibular arch is normal

• arrested at early bud stage when mandibular arch is primitive, leads to hypoplasia, dysplasia, or aplasia at birth

absent submandibular gland ( J:144153 )

• absent when holoprosencephaly is severe or when agnathia is present

endocrine/exocrine glands

abnormal submandibular gland development ( J:144153 )

• normal when the mandibular arch is normal

• arrested at early bud stage when mandibular arch is primitive, leads to hypoplasia, dysplasia, or aplasia at birth

absent submandibular gland ( J:144153 )

• absent when holoprosencephaly is severe or when agnathia is present

embryo

fused first pharyngeal arch ( J:88784 )

• remains fused in the midline at E9.5

growth/size/body

abnormal head morphology ( J:88784 )

• 10% of neonates have lost the most rostral parts of the head

decreased mouth size ( J:144153 )

single external naris ( J:88784 )

• single nostril often seen in association with agnathia and various eye defects

lowered ear position ( J:144153 )

Genotype
MGI:3830682

hm3

• Allelic Composition: Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc
• Genetic Background: involves: 129S7/SvEvBrd * C57BL/6 * FVB/N

mortality/aging

premature death ( J:88784 )

• Background Sensitivity: mice with most severely limited body weights do not survive the first week after weaning

growth/size/body

decreased body size ( J:88784 )

decreased body weight ( J:88784 )

• Background Sensitivity: weight is 60-68% that of control mice at three weeks

• Background Sensitivity: weight is about 80% that of control mice at 12 weeks

skeleton

abnormal vertebrae morphology ( J:88784 )

abnormal caudal vertebrae morphology ( J:88784 )

• ossification is significantly delayed in newborns

decreased caudal vertebrae number ( J:88784 )

• several coccygeal vertebrae are missing

abnormal thoracic vertebrae morphology ( J:88784 )

• truncated or discontinuous neural arches

abnormal cervical vertebrae morphology ( J:88784 )

• ossification is significantly delayed in newborns

• truncated or discontinuous neural arches

abnormal vertebral arch morphology ( J:88784 )

• of cervical and upper thoracic vertebrae

• noticeable at E16.5 and persists to adulthood

abnormal vertebral lamina morphology ( J:88784 )

• lack of lamina development

abnormal vertebral spinous process morphology ( J:88784 )

• partially preserved

• composed of immature cartilage

delayed bone ossification ( J:88784 )

• ossification of cervical and coccygeal vertebrae is significantly delayed in newborns

limbs/digits/tail

abnormal caudal vertebrae morphology ( J:88784 )

• ossification is significantly delayed in newborns

decreased caudal vertebrae number ( J:88784 )

• several coccygeal vertebrae are missing

short tail ( J:88784 )

• as result of several missing coccygeal vertebrae

kinked tail ( J:88784 )

behavior/neurological

abnormal gait ( J:88784 )

• stiffness in about 2% of mice by several weeks of age

• unsteady gait in about 2% of mice by several weeks of age

hindlimb paralysis ( J:88784 )

• partial hind limb paralysis in about 2% of mice by several weeks of age

nervous system

alobar holoprosencephaly ( J:88784 )

• alobar holoprosencephaly

• fails to undergo median cleavage into cerebral hemispheres

respiratory system

abnormal oropharynx morphology ( J:88784 )

• rudimentary

digestive/alimentary system

abnormal foregut morphology ( J:88784 )

• lumen narrowed at E9.5

• foregut separated from notochord unlike controls

Genotype
MGI:5056121

cx4

• Allelic Composition: Trp53^tm1Brd/Trp53^tm1Brd; Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc
• Genetic Background: involves: 129S7/SvEvBrd * C57BL/6

mortality/aging

perinatal lethality, incomplete penetrance ( J:173627 )

• up to 66% of neonates exhibit perinatal death

craniofacial

abnormal craniofacial morphology ( J:173627 )

• mice exhibit reduced craniofacial defects compared with Twsg1^tm1.1Mboc homozygotes

nervous system

exencephaly ( J:173627 )

Genotype
MGI:3830686

cx5

• Allelic Composition: Bmp4^tm2Blh/Bmp4⁺; Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc
• Genetic Background: involves: 129S/SvEv * C57BL/6 * FVB/N

craniofacial

craniofacial phenotype ( J:88784 )

N • no external craniofacial defects between E13.5 and E16.5

Genotype
MGI:3830685

cx6

• Allelic Composition: Chrd^tm1Emdr/Chrd^tm1Emdr; Twsg1^tm1.1Mboc/Twsg1^tm1.1Mboc
• Genetic Background: involves: 129/Sv * C57BL/6 * FVB/N

mortality/aging

perinatal lethality ( J:88784 )

craniofacial

abnormal mandible morphology ( J:88784 )

skeleton

abnormal mandible morphology ( J:88784 )

abnormal vertebral arch morphology ( J:88784 )

nervous system

nervous system phenotype ( J:88784 )

N • no alobar holoprosencephaly at E15.5-E17.5