Phenotypes associated with this allele

• Allele Symbol: Dlx5^tm1Jlr
• Allele Name: targeted mutation 1, John L Rubenstein
• Allele ID: MGI:1857789
• Summary: 3 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Dlx5^tm1Jlr/Dlx5^tm1Jlr	B6.129X1-Dlx5^tm1Jlr	MGI:3702621
hm2	Dlx5^tm1Jlr/Dlx5^tm1Jlr	involves: 129X1/SvJ * C57BL/6J	MGI:2169722
ht3	Dlx5^tm1Jlr/Dlx5^+	involves: 129X1/SvJ * C57BL/6J	MGI:2169723

Genotype
MGI:3702621

hm1

• Allelic Composition: Dlx5^tm1Jlr/Dlx5^tm1Jlr
• Genetic Background: B6.129X1-Dlx5^tm1Jlr

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

nervous system

small vomeronasal organ ( J:81736 )

• at E12.5 or later, the vomeronasal organ is greatly reduced in size

abnormal olfactory bulb morphology ( J:81736 )

• at E14.5 or later, the olfactory bulb (OB) displays altered lamination and lacks distinct neuronal layers

• at E18.5, homozygotes lack an outer nerve layer (ONL), have a thicker mitral cell layer (MC), and appear to have a defect in the migration of subventricular zone (SVZ) cells born at E14.5

• at E18.5, homozygotes exhibit virtual loss of glia in the ONL

• at E18.5, the size of the SVZ appears to be increased relative to the rest of the OB

• at E18.5, homozygotes show a severe reduction of olfactory bulb (OB) local circuit neurons, with granule cells more severely affected than periglomerular cells

• however, no gross abnormalities in the proliferation of OB local circuit neuron progenitors are detected

abnormal rostral migratory stream morphology ( J:81736 )

• at E18.5, homozygotes display reduced (tangential) migration along the RMS

abnormal olfactory bulb granule cell morphology ( J:81736 )

• at E18.5, homozygotes exhibit decreased numbers and altered processes of granule cells

abnormal olfactory bulb periglomerular cell morphology ( J:81736 )

• at E18.5, homozygotes exhibit decreased numbers and altered processes of periglomerular cells

abnormal mitral cell morphology ( J:81736 )

• at E18.5, homozygotes exhibit abnormal MCs with a disrupted radial orientation and hypoplastic dendritic trees

small olfactory bulb ( J:81736 )

• at E14.5, the olfactory ventricle is smaller than normal

• reduction of olfactory bulb size is more prominent at E18.5

abnormal sensory neuron innervation pattern ( J:81736 )

• although some olfactory neurons are formed, they fail to generate olfactory axons that innervate the olfactory bulb

abnormal GABAergic neuron morphology ( J:81736 )

• at E14.5 or later, homozygotes display reduced GABAergic neuron production in the olfactory bulb

abnormal olfactory nerve morphology ( J:81736 )

• at E12.5, only a few, if any, olfactory epithelium axons pass through the cribiform plate or even contact the OB

• at E18.5, homozygotes display deficits in olfactory ensheathing glia in the OB nerve layer

• loss of ONL glia is associated with a dramatic reduction of proliferating cells in the most superficial layer of the OB at E16.5 and E18.5

taste/olfaction

abnormal olfactory epithelium morphology ( J:81736 )

• as early as E10.5, homozygotes display reduced olfactory neuroepithelial structures

• at E12.5, the olfactory epithelium (OE) is hypoplastic and fails to form normal axonal connections with the olfactory bulb

• by E18.5, the OE is significantly reduced in size, with only a few, if any, foramina in the cribiform plate

absent olfactory epithelium ( J:81736 )

• at E14.5, 25% of homozygotes lack an OE altogether

respiratory system

abnormal nasal pit morphology ( J:81736 )

• at E10.5, the olfactory pit (an olfactory placode derivative) is small and lacks thickening of the medial epithelium

small vomeronasal organ ( J:81736 )

• at E12.5 or later, the vomeronasal organ is greatly reduced in size

abnormal olfactory epithelium morphology ( J:81736 )

• as early as E10.5, homozygotes display reduced olfactory neuroepithelial structures

• at E12.5, the olfactory epithelium (OE) is hypoplastic and fails to form normal axonal connections with the olfactory bulb

• by E18.5, the OE is significantly reduced in size, with only a few, if any, foramina in the cribiform plate

absent olfactory epithelium ( J:81736 )

• at E14.5, 25% of homozygotes lack an OE altogether

craniofacial

abnormal craniofacial development ( J:81736 )

abnormal frontonasal prominence morphology ( J:81736 )

• in addition, the size of the lateral frontonasal process and medial frontonasal process are reduced

abnormal nasal pit morphology ( J:81736 )

• at E10.5, the olfactory pit (an olfactory placode derivative) is small and lacks thickening of the medial epithelium

small vomeronasal organ ( J:81736 )

• at E12.5 or later, the vomeronasal organ is greatly reduced in size

abnormal olfactory epithelium morphology ( J:81736 )

• as early as E10.5, homozygotes display reduced olfactory neuroepithelial structures

• at E12.5, the olfactory epithelium (OE) is hypoplastic and fails to form normal axonal connections with the olfactory bulb

• by E18.5, the OE is significantly reduced in size, with only a few, if any, foramina in the cribiform plate

absent olfactory epithelium ( J:81736 )

• at E14.5, 25% of homozygotes lack an OE altogether

growth/size/body

small vomeronasal organ ( J:81736 )

• at E12.5 or later, the vomeronasal organ is greatly reduced in size

abnormal olfactory epithelium morphology ( J:81736 )

• as early as E10.5, homozygotes display reduced olfactory neuroepithelial structures

• at E12.5, the olfactory epithelium (OE) is hypoplastic and fails to form normal axonal connections with the olfactory bulb

• by E18.5, the OE is significantly reduced in size, with only a few, if any, foramina in the cribiform plate

absent olfactory epithelium ( J:81736 )

• at E14.5, 25% of homozygotes lack an OE altogether

Genotype
MGI:2169722

hm2

• Allelic Composition: Dlx5^tm1Jlr/Dlx5^tm1Jlr
• Genetic Background: involves: 129X1/SvJ * C57BL/6J

mortality/aging

perinatal lethality, complete penetrance ( J:56559 )

• all homozygotes die shortly after birth

prenatal lethality, incomplete penetrance ( J:56559 )

• at birth, homozygotes are obtained at non-Mendelian ratios, suggesting embryonic lethality

behavior/neurological

absent gastric milk in neonates ( J:56559 )

• newborn homozygotes lack milk in their stomachs

growth/size/body

abnormal incisor morphology ( J:56559 )

• extensive chondroid bone develops along the incisive alveolar bone at the tips of the dentary

• the incisivium is broader and shorter than normal

• both sets of incisors are shorter and malformed

short lower incisors ( J:56559 )

short upper incisors ( J:56559 )

abnormal molar morphology ( J:56559 )

• the molar alveolae are shorter, broader and deeper

• the alveolar openings are constricted distally and broadened proximally

• the buccal molar walls are weaker and ventrally reflected

abnormal molar crown morphology ( J:56559 )

• the mandicular and maxillary molars display malformed and poorly mineralized crowns

abnormal tooth mineralization ( J:56559 )

• the mandicular and maxillary molars display malformed and poorly mineralized crowns

abnormal nasal bone morphology ( J:56559 )

• in most cases, nasal bones are dysmorphic

small nasal bone ( J:56559 )

• in most cases

turbinate hypoplasia ( J:56559 )

• in most cases, the tectum nasi, solum and paries nasi prominences and associated turbinates are hypoplastic

abnormal nasal capsule morphology ( J:56559 )

• newborns display reduced nasal capsular breadth, with chondrocranial and dermatocranial defects in and around the nasal capsule and mesethmoid

• in severe cases, newborns show a symmetric near aplasia of the capsule and mesethmoid

• small, cartilaginous spicules are the only remnants of the side walls of the nasal capsule

• in less severe cases, cartilages in the floor of the nasal capsule are hypoplastic and often associated with a rudimentary vomeronasal organ

abnormal pterygoid muscle morphology ( J:56559 )

• the medial pterygoid is hypertrophic; its insertion groove is occluded by a broad origin for an abnormal mylohyoid

cleft primary palate ( J:56559 )

• 88% of newborns exhibit primary and secondary palates with variable degrees of clefting

cleft secondary palate ( J:56559 )

• 88% of newborns exhibit primary and secondary palates with variable degrees of clefting

abnormal tongue muscle morphology ( J:56559 )

• the right side of the rostral tongue is hypertrophied ventrally

abnormal intrinsic tongue muscle morphology ( J:56559 )

• the course of the lingual duct and the fascicle pattern of the intrinsic tongue musculature is variably affected

abnormal nasal mucosa morphology ( J:56559 )

• in severe cases, the posterior nasal capsule and mesethmoid are reduced, with no evidence of a developing nasal epithelium, true tectum or solum

• in less severe cases, rudimentary branches of the nasal epithelium are present

absent vomeronasal organ ( J:56559 )

• in severe cases, paraseptal cartilages and the vomeronasal organ fail to deveop

deviated nasal septum ( J:56559 )

• in most cases (intermediate severity), the trabecular plate-nasal septum deviates to the right; no foramina cribrosa are found on the right and very few on the left

short nasal septum ( J:56559 )

• in severe cases, a dorsoventrally expanded nasal septum fails to develop (i.e. shortened dorsoventrally)

abnormal outer ear morphology ( J:56559 )

• newborns exhibit malformed auditory pinnae

abnormal external auditory canal morphology ( J:56559 )

• the external acoustic meatus is shorter and the tubal cartilage develops in nodules

abnormal outer ear cartilage morphology ( J:56559 )

• tubal cartilage develops in nodules

decreased body size ( J:56559 )

• newborn homozygotes are slightly smaller than wild-type littermates

craniofacial

abnormal cranium morphology ( J:56559 )

• newborns exhibit variable abnormalities in all cranial bones

• only a few abnormalities are detected in post-cranial axial and appendicular skeleton

abnormal Meckel's cartilage morphology ( J:56559 )

• at E13.5 and E15.5, Meckel's cartilage is shorter and its proximal shaft is severely dysmorphic; the MC orientation deviates twice

short Meckel's cartilage ( J:56559 )

• at E13.5 and E15.5, Meckel's cartilage is shorter than normal

abnormal neurocranium morphology ( J:56559 )

• all non-exencephalic newborns have calvarial roofs (calottes) with small, hypomineralized parietal and interparietal bones

• in contrast, frontals appear to exhibit normal mineralization

small interparietal bone ( J:56559 )

• all non-exencephalic newborns display small, hypomineralized interparietal bones

abnormal occipital bone morphology ( J:56559 )

• all non-exencephalic newborns display thicker occipital arch cartilages that expand rostrocaudally

small supraoccipital bone ( J:56559 )

• all non-exencephalic newborns display small supraoccipital bones with a reduced degree of hypomineralization

small parietal bone ( J:56559 )

• all non-exencephalic newborns display small, hypomineralized parietal bones

abnormal alisphenoid bone morphology ( J:56559 )

• alisphenoid bones are slightly dysmorphic

abnormal pterygoid bone morphology ( J:56559 )

• the pterygoids have an abnormal amount of chondroid bone and secondary cartilage

abnormal temporal bone squamous part morphology ( J:56559 )

• squamosal bones are slightly dysmorphic

abnormal incisor morphology ( J:56559 )

• extensive chondroid bone develops along the incisive alveolar bone at the tips of the dentary

• the incisivium is broader and shorter than normal

• both sets of incisors are shorter and malformed

short lower incisors ( J:56559 )

short upper incisors ( J:56559 )

abnormal molar morphology ( J:56559 )

• the molar alveolae are shorter, broader and deeper

• the alveolar openings are constricted distally and broadened proximally

• the buccal molar walls are weaker and ventrally reflected

abnormal molar crown morphology ( J:56559 )

• the mandicular and maxillary molars display malformed and poorly mineralized crowns

abnormal tooth mineralization ( J:56559 )

• the mandicular and maxillary molars display malformed and poorly mineralized crowns

abnormal mandible morphology ( J:56559 )

• a short and abnormal dentary develops around Meckel's cartilage

abnormal mandibular angle morphology ( J:56559 )

• the condylar and angular processes are shorterned, malformed and juxtaposed

abnormal mandibular condyloid process morphology ( J:56559 )

• the condylar and angular processes are shorterned, malformed and juxtaposed

abnormal mandibular coronoid process morphology ( J:56559 )

• the proximal lamina of the coronoid is absent

abnormal maxilla morphology ( J:56559 )

• in most cases, the maxillae are dysmorphic

abnormal premaxilla morphology ( J:56559 )

• in most cases, the premaxillae are dysmorphic

short premaxilla ( J:56559 )

• in most cases

small maxilla ( J:56559 )

• in most cases

micrognathia ( J:56559 )

• newborns exhibit micrognathia

abnormal lacrimal bone morphology ( J:56559 )

• in most cases, lacrimal bones are small and dysmorphic

small lacrimal bone ( J:56559 )

• in most cases

abnormal nasal bone morphology ( J:56559 )

• in most cases, nasal bones are dysmorphic

small nasal bone ( J:56559 )

• in most cases

turbinate hypoplasia ( J:56559 )

• in most cases, the tectum nasi, solum and paries nasi prominences and associated turbinates are hypoplastic

abnormal vomer bone morphology ( J:56559 )

• in most cases, the vomer bones are small and dysmorphic

small vomer bone ( J:56559 )

ectopic cranial bone ( J:56559 )

• in 88% of homozygotes, ectopic membrane bones (parapalatines) develop caudal to the palatine shelves and rostral to the dysmorphic pterygoids

abnormal malleus morphology ( J:56559 )

• the malleus is caudally extended and thickened at the level of the manumbrium

small malleus processus brevis ( J:56559 )

• the malleus has a smaller than normal processus brevis

frontonasal prominence hypoplasia ( J:56559 )

• at E10.5, frontonasal prominences are hypoplastic

abnormal lateral nasal prominence morphology ( J:56559 )

• at E12.5, the lateral frontonasal prominence is severely reduced

abnormal nasal capsule morphology ( J:56559 )

• newborns display reduced nasal capsular breadth, with chondrocranial and dermatocranial defects in and around the nasal capsule and mesethmoid

• in severe cases, newborns show a symmetric near aplasia of the capsule and mesethmoid

• small, cartilaginous spicules are the only remnants of the side walls of the nasal capsule

• in less severe cases, cartilages in the floor of the nasal capsule are hypoplastic and often associated with a rudimentary vomeronasal organ

abnormal pterygoid muscle morphology ( J:56559 )

• the medial pterygoid is hypertrophic; its insertion groove is occluded by a broad origin for an abnormal mylohyoid

cleft primary palate ( J:56559 )

• 88% of newborns exhibit primary and secondary palates with variable degrees of clefting

cleft secondary palate ( J:56559 )

• 88% of newborns exhibit primary and secondary palates with variable degrees of clefting

abnormal tongue muscle morphology ( J:56559 )

• the right side of the rostral tongue is hypertrophied ventrally

abnormal intrinsic tongue muscle morphology ( J:56559 )

• the course of the lingual duct and the fascicle pattern of the intrinsic tongue musculature is variably affected

abnormal nasal mucosa morphology ( J:56559 )

• in severe cases, the posterior nasal capsule and mesethmoid are reduced, with no evidence of a developing nasal epithelium, true tectum or solum

• in less severe cases, rudimentary branches of the nasal epithelium are present

absent vomeronasal organ ( J:56559 )

• in severe cases, paraseptal cartilages and the vomeronasal organ fail to deveop

deviated nasal septum ( J:56559 )

• in most cases (intermediate severity), the trabecular plate-nasal septum deviates to the right; no foramina cribrosa are found on the right and very few on the left

short nasal septum ( J:56559 )

• in severe cases, a dorsoventrally expanded nasal septum fails to develop (i.e. shortened dorsoventrally)

abnormal outer ear morphology ( J:56559 )

• newborns exhibit malformed auditory pinnae

abnormal external auditory canal morphology ( J:56559 )

• the external acoustic meatus is shorter and the tubal cartilage develops in nodules

abnormal outer ear cartilage morphology ( J:56559 )

• tubal cartilage develops in nodules

hearing/vestibular/ear

abnormal outer ear morphology ( J:56559 )

• newborns exhibit malformed auditory pinnae

abnormal external auditory canal morphology ( J:56559 )

• the external acoustic meatus is shorter and the tubal cartilage develops in nodules

abnormal outer ear cartilage morphology ( J:56559 )

• tubal cartilage develops in nodules

abnormal cochlea morphology ( J:56559 )

• the cochlea is reduced and the cochlea fenestra is abnormal in size and orientation

abnormal scala vestibuli morphology ( J:56559 )

• at E16.5, the perilyphatic spaces have expanded and spiral laminae are abnormal

• a cartilaginous shelf separates the cochlea from the scala vestibuli

decreased cochlea coiling ( J:56559 )

• the cochlea completes roughly only one coil instead of one and a half

decreased lateral semicircular canal size ( J:56559 )

• at E16.5, the lateral SCC has a complete but shorter cartilaginous canal

absent posterior semicircular canal ( J:56559 )

• at E16.5 and P0

absent superior semicircular canal ( J:56559 )

• at E16.5 and P0

absent endolymphatic duct ( J:56559 )

otic capsule hypoplasia ( J:56559 )

• at E16.5, the pars canicularis is malformed and hypoplastic, as the anterior and posterior SCCs do not form, while the pars cochlearis is smaller

abnormal middle ear morphology ( J:56559 )

abnormal stapedial artery morphology ( J:56559 )

• the course of stapedial artery is variably affected

abnormal malleus morphology ( J:56559 )

• the malleus is caudally extended and thickened at the level of the manumbrium

small malleus processus brevis ( J:56559 )

• the malleus has a smaller than normal processus brevis

abnormal epitympanic recess morphology ( J:56559 )

• at P0, the epitympanic recess is expanded

abnormal tegmen tympani morphology ( J:56559 )

• at P0, the tegmen tympani (TT) is hypertrophic

• the TT maintains a prolonged synovial contact with the malleus and incus, and it shares origins for the tensor tympani with a novel structure ("os paradoxicum") and the gonial

• notably, the stapes, styloid process and incus are all present

decreased tympanic ring size ( J:56559 )

• the tympanic is slightly smaller and thicker

nervous system

abnormal axon extension ( J:56559 )

• at E10.5, axonal defects are noted in the trigeminall ganglion, the processes of the hypoglossal nerve, the autonomic ganglion chain, and the dorsal root ganglion

• at later stages, trigeminal nerve axons extend further into the branchial arches, albeit with abnormal orientations

absent vomeronasal organ ( J:56559 )

• in severe cases, paraseptal cartilages and the vomeronasal organ fail to deveop

open neural tube ( J:56559 )

• at E9.0-E13.5, homozygotes display an open neural tube; the defect is generally centered around the midbrain but can extend rostrally and caudally in severe cases

exencephaly ( J:56559 )

• 28% of newborns display exencephaly

small trigeminal ganglion ( J:56559 )

• at E10.5, the trigeminal ganglion is smaller than normal, its root is malformed, and it has reduced axonal projections into the mesenchyme

respiratory system

abnormal nasal bone morphology ( J:56559 )

• in most cases, nasal bones are dysmorphic

small nasal bone ( J:56559 )

• in most cases

turbinate hypoplasia ( J:56559 )

• in most cases, the tectum nasi, solum and paries nasi prominences and associated turbinates are hypoplastic

abnormal nasal capsule morphology ( J:56559 )

• newborns display reduced nasal capsular breadth, with chondrocranial and dermatocranial defects in and around the nasal capsule and mesethmoid

• in severe cases, newborns show a symmetric near aplasia of the capsule and mesethmoid

• small, cartilaginous spicules are the only remnants of the side walls of the nasal capsule

• in less severe cases, cartilages in the floor of the nasal capsule are hypoplastic and often associated with a rudimentary vomeronasal organ

abnormal nasal mucosa morphology ( J:56559 )

• in severe cases, the posterior nasal capsule and mesethmoid are reduced, with no evidence of a developing nasal epithelium, true tectum or solum

• in less severe cases, rudimentary branches of the nasal epithelium are present

absent vomeronasal organ ( J:56559 )

• in severe cases, paraseptal cartilages and the vomeronasal organ fail to deveop

deviated nasal septum ( J:56559 )

• in most cases (intermediate severity), the trabecular plate-nasal septum deviates to the right; no foramina cribrosa are found on the right and very few on the left

short nasal septum ( J:56559 )

• in severe cases, a dorsoventrally expanded nasal septum fails to develop (i.e. shortened dorsoventrally)

abnormal mylohyoid muscle morphology ( J:56559 )

abnormal larynx morphology ( J:56559 )

• the larynx is displaced caudally, well back from the pterygoids and tympanic cavity

abnormal superior horn of thyroid cartilage morphology ( J:56559 )

• the superior cornu of the thyroid cartilage (derived from the fourth branchial arch) fails to form

skeleton

abnormal cranium morphology ( J:56559 )

• newborns exhibit variable abnormalities in all cranial bones

• only a few abnormalities are detected in post-cranial axial and appendicular skeleton

abnormal Meckel's cartilage morphology ( J:56559 )

• at E13.5 and E15.5, Meckel's cartilage is shorter and its proximal shaft is severely dysmorphic; the MC orientation deviates twice

short Meckel's cartilage ( J:56559 )

• at E13.5 and E15.5, Meckel's cartilage is shorter than normal

abnormal neurocranium morphology ( J:56559 )

• all non-exencephalic newborns have calvarial roofs (calottes) with small, hypomineralized parietal and interparietal bones

• in contrast, frontals appear to exhibit normal mineralization

small interparietal bone ( J:56559 )

• all non-exencephalic newborns display small, hypomineralized interparietal bones

abnormal occipital bone morphology ( J:56559 )

• all non-exencephalic newborns display thicker occipital arch cartilages that expand rostrocaudally

small supraoccipital bone ( J:56559 )

• all non-exencephalic newborns display small supraoccipital bones with a reduced degree of hypomineralization

small parietal bone ( J:56559 )

• all non-exencephalic newborns display small, hypomineralized parietal bones

abnormal alisphenoid bone morphology ( J:56559 )

• alisphenoid bones are slightly dysmorphic

abnormal pterygoid bone morphology ( J:56559 )

• the pterygoids have an abnormal amount of chondroid bone and secondary cartilage

abnormal temporal bone squamous part morphology ( J:56559 )

• squamosal bones are slightly dysmorphic

abnormal incisor morphology ( J:56559 )

• extensive chondroid bone develops along the incisive alveolar bone at the tips of the dentary

• the incisivium is broader and shorter than normal

• both sets of incisors are shorter and malformed

short lower incisors ( J:56559 )

short upper incisors ( J:56559 )

abnormal molar morphology ( J:56559 )

• the molar alveolae are shorter, broader and deeper

• the alveolar openings are constricted distally and broadened proximally

• the buccal molar walls are weaker and ventrally reflected

abnormal molar crown morphology ( J:56559 )

• the mandicular and maxillary molars display malformed and poorly mineralized crowns

abnormal tooth mineralization ( J:56559 )

• the mandicular and maxillary molars display malformed and poorly mineralized crowns

abnormal mandible morphology ( J:56559 )

• a short and abnormal dentary develops around Meckel's cartilage

abnormal mandibular angle morphology ( J:56559 )

• the condylar and angular processes are shorterned, malformed and juxtaposed

abnormal mandibular condyloid process morphology ( J:56559 )

• the condylar and angular processes are shorterned, malformed and juxtaposed

abnormal mandibular coronoid process morphology ( J:56559 )

• the proximal lamina of the coronoid is absent

abnormal maxilla morphology ( J:56559 )

• in most cases, the maxillae are dysmorphic

abnormal premaxilla morphology ( J:56559 )

• in most cases, the premaxillae are dysmorphic

short premaxilla ( J:56559 )

• in most cases

small maxilla ( J:56559 )

• in most cases

micrognathia ( J:56559 )

• newborns exhibit micrognathia

abnormal lacrimal bone morphology ( J:56559 )

• in most cases, lacrimal bones are small and dysmorphic

small lacrimal bone ( J:56559 )

• in most cases

abnormal nasal bone morphology ( J:56559 )

• in most cases, nasal bones are dysmorphic

small nasal bone ( J:56559 )

• in most cases

turbinate hypoplasia ( J:56559 )

• in most cases, the tectum nasi, solum and paries nasi prominences and associated turbinates are hypoplastic

abnormal vomer bone morphology ( J:56559 )

• in most cases, the vomer bones are small and dysmorphic

small vomer bone ( J:56559 )

ectopic cranial bone ( J:56559 )

• in 88% of homozygotes, ectopic membrane bones (parapalatines) develop caudal to the palatine shelves and rostral to the dysmorphic pterygoids

abnormal malleus morphology ( J:56559 )

• the malleus is caudally extended and thickened at the level of the manumbrium

small malleus processus brevis ( J:56559 )

• the malleus has a smaller than normal processus brevis

abnormal nasal capsule morphology ( J:56559 )

• newborns display reduced nasal capsular breadth, with chondrocranial and dermatocranial defects in and around the nasal capsule and mesethmoid

• in severe cases, newborns show a symmetric near aplasia of the capsule and mesethmoid

• small, cartilaginous spicules are the only remnants of the side walls of the nasal capsule

• in less severe cases, cartilages in the floor of the nasal capsule are hypoplastic and often associated with a rudimentary vomeronasal organ

abnormal outer ear cartilage morphology ( J:56559 )

• tubal cartilage develops in nodules

abnormal superior horn of thyroid cartilage morphology ( J:56559 )

• the superior cornu of the thyroid cartilage (derived from the fourth branchial arch) fails to form

abnormal rib morphology ( J:56559 )

• 27% of newborns display a sinusoidal rib angle

decreased bone mineralization ( J:56559 )

• all newborns display hypomineralized calottes (calvarial roofs)

muscle

abnormal pterygoid muscle morphology ( J:56559 )

• the medial pterygoid is hypertrophic; its insertion groove is occluded by a broad origin for an abnormal mylohyoid

abnormal tongue muscle morphology ( J:56559 )

• the right side of the rostral tongue is hypertrophied ventrally

abnormal intrinsic tongue muscle morphology ( J:56559 )

• the course of the lingual duct and the fascicle pattern of the intrinsic tongue musculature is variably affected

abnormal mylohyoid muscle morphology ( J:56559 )

cardiovascular system

abnormal stapedial artery morphology ( J:56559 )

• the course of stapedial artery is variably affected

digestive/alimentary system

cleft primary palate ( J:56559 )

• 88% of newborns exhibit primary and secondary palates with variable degrees of clefting

cleft secondary palate ( J:56559 )

• 88% of newborns exhibit primary and secondary palates with variable degrees of clefting

abnormal tongue muscle morphology ( J:56559 )

• the right side of the rostral tongue is hypertrophied ventrally

abnormal intrinsic tongue muscle morphology ( J:56559 )

• the course of the lingual duct and the fascicle pattern of the intrinsic tongue musculature is variably affected

embryo

open neural tube ( J:56559 )

• at E9.0-E13.5, homozygotes display an open neural tube; the defect is generally centered around the midbrain but can extend rostrally and caudally in severe cases

cellular

abnormal axon extension ( J:56559 )

• at E10.5, axonal defects are noted in the trigeminall ganglion, the processes of the hypoglossal nerve, the autonomic ganglion chain, and the dorsal root ganglion

• at later stages, trigeminal nerve axons extend further into the branchial arches, albeit with abnormal orientations

Genotype
MGI:2169723

ht3

• Allelic Composition: Dlx5^tm1Jlr/Dlx5⁺
• Genetic Background: involves: 129X1/SvJ * C57BL/6J

behavior/neurological

abnormal sexual interaction ( J:56559 )

• heterozygotes do not breed readily

nervous system

exencephaly ( J:56559 )

• ~3% of newborn heterozygotes display exencephaly

• Background Sensitivity: the frequency of exencephalic heterozygotes (~3%) is significantly reduced with further outbreeding to C57BL/6J