Mouse Genome Informatics
hm1
    Dlx5/Dlx6tm1Tlu/Dlx5/Dlx6tm1Tlu
involves: Swiss Webster
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
hearing/vestibular/ear
• at E14.5 and E18.5, homozygotes display rudimentary external ear structures
• at E9.5, the mutant otocyst is reduced while the otic epithelium is thickened
• at E10.5, the otic vesicle is compressed in both the anterorposterior and dorsoventral planes
• at E10.5, the otic vesicle is abnormally closer to the second branchial arch and farther away from the dorsal neural tube, while the dorsal otic epithelium is relatively closer to the ventral otic epithelium in 95% of cases
• at E11.5, the luminal space of otic vesicles is significantly reduced and appears long and narrow along the mediolateral axis in the dorsoventral plane
• at later stages, all the dorsally-derived otic structures fail to form; only a rudimentary, ventrally-derived cochlea is observed
• at E9.5 and E10.5, BrdU staining indicates decreased cell proliferation in the medial and lateral otic epithelium, while proliferation rates in the periotic mesenchyme remain normal
• at E10.5, TUNEL staining shows increased cell death in both the ventrolateral otic epithelium and periotic mesenchyme
• mutant otic vesicles appear smaller at E9.5 and developmentally retarded at E10.5
• by E11.5, the mutant inner ear resembles an undifferentiated sphere that is half the size of wild-type inner ear
• at E16.5, mutant cochlear structures are smaller, rudimentary and completely encapsulated by cartilage
• in addition, mutant cochleas are markedly elongated, vacuolated and rotated caudally
• at E18.5, no ampullae are detected
• at E11.5, developing semicircular ducts are completely absent
• at E18.5, no utricle is recognized
• at E18.5, no saccule is recognized
• at E16.5, the entire vestibular portion of the inner ear is presumably absent
• at E10.5, the outgrowth of the endolymphatic duct fails to form
• at E11.5, the endolymphatic duct is completely absent
• at E16.5 and E18.5, dysmorphic cartilage capsule-like structures adjacent to the basioccipital bone but positioned away form the midline are observed
• at E18.5, cartilage structures that normally compose the vestibular portion of the otic capsule are completely absent
• any remaining cartilage structures are slightly rotated toward the midline and resemble abnormal otic capsules surrounding a presumptive cochlea
• at E16.5 and E18.5, dysmorphic cartilage capsule-like structures are smaller than normal

craniofacial
• at E14.5 and E18.5, homozygotes display rudimentary external ear structures


Mouse Genome Informatics
hm2
    Dlx5/Dlx6tm1Tlu/Dlx5/Dlx6tm1Tlu
Not Specified
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
mortality/aging
• homozygotes are viable up to E18.5

craniofacial
• at E16.5, homozygotes show complete absence of calvaria
• at E18.5, mandibular structures are dysmorphic
• at E16.5, the mandibular bone is absent
• at E18.5, maxillary structures are dysmorphic
• at E16.5, the maxillary bone is absent
• at E18.5, nasal structures are dysmorphic
• at E14.5, Meckel's cartilage is completely absent
• at E11.5, homozygotes display dysmorphic branchial arch derivatives
• at E14.5, the outgrowth of the dysmorphic nasal prominence is curved caudally (J:76480)
• the nasal cartilage is hypoplastic (J:139700)
• at E14.5, homozygotes show severe clefting of the entire nasal cavity
• at E14.5, external ear cartilage is absent

skeleton
• at E14.5, all combinations of the central digits are absent, with missing cartilage including phalanges, metatarsals, and tarsals
• at E16.5, the axial skeleton, including vertebral bodies shows little or no ossification
• at E16.5, homozygotes show complete absence of calvaria
• at E18.5, mandibular structures are dysmorphic
• at E16.5, the mandibular bone is absent
• at E18.5, maxillary structures are dysmorphic
• at E16.5, the maxillary bone is absent
• at E18.5, nasal structures are dysmorphic
• at E16.5 and E18.5, the ribs are malformed, esp. in the region proximal to the vertebral column
• at E16.5, accumulation of mature osteoblasts is severely retarded or absent in mutant scapulas
• at E14.5, cartilage giving rise to the cranial floor (basioccipital, basisphenoid, and sphenoid) and frontonasal prominence are present, but show severe patterning defects
• at E14.5, cartilage from the exoccipital and ventral temporal bone primordia extending to the distal nasal capsule appear condensed and fused
• at E16.5, the dysmorphic cranial cartilage structure remains unossified
• at E14.5, Meckel's cartilage is completely absent
• at E14.5, the outgrowth of the dysmorphic nasal prominence is curved caudally (J:76480)
• the nasal cartilage is hypoplastic (J:139700)
• at E14.5, Alcian blue staining indicates absence of cartilage in frontonasal, supraoccipital, and rostral temporal areas, nasal prominence and central digits
• at E14.5, external ear cartilage is absent
• at E16.5, homozygotes display either delayed or no ossification in the forelimbs
• at E16.5, the dysmorphic cranial cartilage structure remains unossified
• at E16.5, the axial skeleton, including vertebral bodies shows little or no ossification
• delay in ossification becomes less severe in the axial and appendicular skeleton by E18.5
• at E16.5, endochondral ossification is either absent or delayed in all bones of the appendicular and axial skeleton
• at E18.5, transition from a cartilaginous to ossified skeleton remains severely retarded

limbs/digits/tail
• at E11.5, the medial portion at the hindlimb AER is thinner and the distal edge of the hindlimb is flattened
• at E10.5 and E11.5, BrdU incorporation indicates decreased cellular proliferation in the medial AER with subsequent loss of limb structures (medial digits), while proliferation in the underlying mesenchyme is unaffected
• at E16.5 and E18.5, forelimb and hindlimb digits are absent and/or fused
• at E14.5, the central digit is most commonly lost
• by E14.5, one to three of the central hindlimb digits are absent in all homozygotes
• at E14.5, the central hindlimb digit is absent while the remaining adjacent digits tend to be either misshapen or fused at phalanges or metatarsals
• similar defects are occasionally observed in the forelimbs
• at E16.5, forelimbs display either delayed or no ossification
• at E18.5, the ratio of forelimb ossification to cartilage remains retarded
• at E18.5, forelimbs display clefting due to missing and/or fused digits
• at E18.5, homozygotes display split hindlimbs with complete penetrance
• at E11.5, the distal edge of hindlimbs is flattened
• at E16.5, hindlimbs display clefting due to missing and/or fused digits
• at E14.5, all combinations of the central digits are absent, with missing cartilage including phalanges, metatarsals, and tarsals
• at E11.5, mutant embryos exhibit kinked tail vertebrae

nervous system
• at E9.5, the anterior neuropore fails to close
• at E18.5, homozygotes display exencephaly, leading to cerebral trauma during fetal delivery and massive postnatal blood loss

hearing/vestibular/ear
• at E14.5, external ear cartilage is absent
• at E11.5, homozygotes show absence of inner ear structures
• at E14.5, the inner ear capsule and middle ear cartilages are fused and highly dysmorphic (J:76480)
• mice are dorsally deficient in the otic capsule (J:139700)
• at E14.5, the inner ear capsule and middle ear cartilages are fused and highly dysmorphic

vision/eye
• at E11.5, homozygotes show absence of developing eyes
• at E18.5, homozygotes display reduced eye size

respiratory system
• at E14.5, the outgrowth of the dysmorphic nasal prominence is curved caudally (J:76480)
• the nasal cartilage is hypoplastic (J:139700)
• at E14.5, homozygotes show severe clefting of the entire nasal cavity

growth/size
• at E18.5, homozygotes display an overall reduced size relative to wild-type fetuses

embryogenesis
• at E11.5, homozygotes display dysmorphic branchial arch derivatives
• at E11.5, the medial portion at the hindlimb AER is thinner and the distal edge of the hindlimb is flattened
• at E10.5 and E11.5, BrdU incorporation indicates decreased cellular proliferation in the medial AER with subsequent loss of limb structures (medial digits), while proliferation in the underlying mesenchyme is unaffected
• at E9.5, the anterior neuropore fails to close

Mouse Models of Human Disease
OMIM IDRef(s)
Split-Hand/Foot Malformation 1; SHFM1 183600 J:76480