Mouse Genome Informatics
hm1
    Six1tm1Mair/Six1tm1Mair
either: (involves: 129/Sv) or (involves: 129/Sv * C57BL/6)
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
mortality/aging

muscle
• homozygotes display impaired primary myogenesis of most body muscles
• at E13.5, all body muscles are either absent or severely disorganized, except some deep back and head muscles
• at E13.5, at the trunk level, the external myogenic layer (cutaneus maximus) is absent while the internal myogenic layer is reduced and disorganized
• most muscles at the shoulder level are absent, the latissimus dorsi is disorganized, and the abdominal and thoracic muscles are severly reduced
• at E13.5, homozygotes display a severe reduction and disorganisation of primary myofibers in most body muscles
• although hypaxial progenitors are correctly specified in somites, migrate normally into the limb buds and do not undergo apoptosis, they fail to activate MyoD and myogenin at E11.5
• at E18.5, the diaphragm is devoid of skeletal muscle fibers and appears as a thin layer of connective tissue
• at E18.5, back intercostal muscles are present but slightly reduced
• at E18.5, homozygotes display reduced muscle mass, especially in distal territories
• at E18.5, homozygotes show extensive muscle hypoplasia affecting most of epaxial and hypaxial body muscles, esp. in certain hypaxial muscle groups
• at the distal forelimb level, dorsal muscles are absent and ventral muscles are strongly reduced
• at the distal hindlimb level, most ventral and intermediate muscles are absent, whereas dorsal muscles are only slightly reduced
• some superficial back muscles e.g. the trapezius, the latissimus dorsi and the serratus dorsalis are severely reduced or even absent
• at the head level, only the tongue and related muscles e.g. the genioglossus are markedly reduced
• back intercostal muscles are only slightly reduced
• reduced muscle size is due to a reduced number of myofibers; however, the decrease in the number of myofibers is quite variable in different muscles, ranging from a ~10% reduction in dorsal intercostal muscles to 50% in ventral intercostal muscles, 33% in tibialis anterior and 100% in soleus, plantaris and medial gastrocnemius
• notably, remaining myofibers are properly differentiated into fast and slow types
• in contrast to muscles, the tendons and connective tissue appear to be properly developed

skeleton
• at E18.5, homozygotes display truncated distal ribs not attached to the sternum
• only 2 of 5 homozygotes show one or two ribs left attached to the sternum
• at E18.5, homozygotes show disorganized sternum ossification
• at E18.5, all homozygotes display variable and asymmetric rib defects, with the right side more strongly affected
• at E18.5, homozygotes display rib bifurcations
• at E18.5, homozygotes display fusion of cartilage segments from adjacent ribs

craniofacial
• at E18.5, the tongue and related muscles such as the genioglossus are markedly reduced
• other head muscles e.g the masseter appear correctly developed

digestive/alimentary system
• at E18.5, the tongue and related muscles such as the genioglossus are markedly reduced
• other head muscles e.g the masseter appear correctly developed

growth/size/body
• at E18.5, the tongue and related muscles such as the genioglossus are markedly reduced
• other head muscles e.g the masseter appear correctly developed


Mouse Genome Informatics
hm2
    Six1tm1Mair/Six1tm1Mair
involves: 129 * C57BL/6 * CD-1 * SJL
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
cardiovascular system
• less than 5% of embryos show cardiovascular defects at E17.5


Mouse Genome Informatics
hm3
    Six1tm1Mair/Six1tm1Mair
involves: 129S1/Sv * 129X1/SvJ * C57BL/6
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
cardiovascular system
• 5% of embryos display duplicated left common carotid artery
• 5% of mutants have great vessel defects

craniofacial
• dysmorphogenesis of the midface and deformation of nasal structures are observed in some embryos

muscle
• embryos have severely hypolplastic branchiomeric muscles

skeleton


Mouse Genome Informatics
hm4
    Six1tm1Mair/Six1tm1Mair
involves: 129S2/SvPas
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
craniofacial
• at E18.5, homozygotes display severe craniofacial bone abnormalities
• at E18.5, frontal and nasal bones form an obtuse angle and are not properly aligned
• at E18.5
• at E18.5, the styloid process is rudimentary
• at E18.5, the greater horns of the hyoid bone are rudimentary
• at E18.5
• at E18.5
• at E18.5, frontal and nasal bones form an obtuse angle and are not properly aligned
• at E18.5
• at E18.5, Meckel's cartilage is rudimentary
• at E18.5, homozygotes show a characteristic angle at the nose level between the frontal bone and nasal bone
• at E18.5, the nasal cavity is not reticulated, indicating that chonchae fail to form
• newborns display extensive disorganization of the nasal cavity; no lateral reticulation is observed
• in contrast, the teeth primordium and the vibrissae follicules are correctly developed
• at E18.5, the deep layer of the olfactory epithelium is missing
• in contrast, the surrounding mesenchyme and cartilage appear correctly developed

endocrine/exocrine glands
• at E18.5, parotid glands are absent, even though the parotid ducts seem correctly elongated
• at E18.5, submandibular glands are reduced
• however, submandibular gland acini appear histologically normal
• at E18.5, lacrimal glands are severely disorganized and reduced, and abnormally localized close to the eye, as if the lacrimal ducts fail to elongate posteriorly
• in newborns, the thymus is absent

hearing/vestibular/ear
• at E13.5, BrdU/eosin staining indicates absence of the epithelium in the otic vesicle
• newborns display extensive disorganization of the inner ear
• in contrast, the external and middle ears are correctly shaped
• at E18.5, the cochlear duct is unrecognizable; only a residual duct is present
• at E18.5, the semicircular ducts are unrecognizable
• at E13.5, the otic capsule is strikingly reduced, whereas Rathke's pouch and the trigeminal ganglia (V) and the otic ganglia (IX) are still present
• however, development of the otic vesicle is correctly initiated at E11.5

muscle
• at E18.5, epaxial muscles are slightly reduced
• at E18.5, hypaxial muscles are severely reduced
• at E18.5, the diaphragm muscle is absent

skeleton
• at E18.5, homozygotes display severe craniofacial bone abnormalities
• at E18.5, frontal and nasal bones form an obtuse angle and are not properly aligned
• at E18.5
• at E18.5, the styloid process is rudimentary
• at E18.5, the greater horns of the hyoid bone are rudimentary
• at E18.5
• at E18.5
• at E18.5, frontal and nasal bones form an obtuse angle and are not properly aligned
• at E18.5, the nasal cavity is not reticulated, indicating that chonchae fail to form
• at E18.5
• at E18.5, Meckel's cartilage is rudimentary
• at E18.5, the atlas and axis are fused

vision/eye
• at E18.5, lacrimal glands are severely disorganized and reduced, and abnormally localized close to the eye, as if the lacrimal ducts fail to elongate posteriorly

digestive/alimentary system
• at E18.5, parotid glands are absent, even though the parotid ducts seem correctly elongated
• at E18.5, submandibular glands are reduced
• however, submandibular gland acini appear histologically normal

embryogenesis
• homozygotes show abnormal neural crest development, as shown by defects in formation of Meckel's cartilage, styloid process, and the greater horns of the hyoid bone

nervous system
• homozygotes show abnormal neural crest development, as shown by defects in formation of Meckel's cartilage, styloid process, and the greater horns of the hyoid bone

renal/urinary system
• at E13.5, the metanephros fails to develop whereas the mesonephric duct and the gonads develop correctly
• at E13.5, homozygotes display renal agenesis, probably due to defects in metanephric blastema differentiation

respiratory system
• at E18.5, homozygotes show a characteristic angle at the nose level between the frontal bone and nasal bone
• at E18.5, the nasal cavity is not reticulated, indicating that chonchae fail to form
• newborns display extensive disorganization of the nasal cavity; no lateral reticulation is observed
• in contrast, the teeth primordium and the vibrissae follicules are correctly developed
• at E18.5, the deep layer of the olfactory epithelium is missing
• in contrast, the surrounding mesenchyme and cartilage appear correctly developed

taste/olfaction
• at E18.5, histology of the olfactory system is altered
• the olfactive cavity is severely disorganized
• at E18.5, the deep layer of the olfactory epithelium is missing
• in contrast, the surrounding mesenchyme and cartilage appear correctly developed

cellular
• at E13.5, BrdU/eosin staining indicates absence of the epithelium in the otic vesicle

hematopoietic system
• in newborns, the thymus is absent

immune system
• in newborns, the thymus is absent

mortality/aging
• homozygotes die at birth due to absence of the diaphragm muscle and thoracic skeletal defects that could prevent proper breathing

growth/size/body
• at E18.5, homozygotes show a characteristic angle at the nose level between the frontal bone and nasal bone
• at E18.5, the nasal cavity is not reticulated, indicating that chonchae fail to form
• newborns display extensive disorganization of the nasal cavity; no lateral reticulation is observed
• in contrast, the teeth primordium and the vibrissae follicules are correctly developed
• at E18.5, the deep layer of the olfactory epithelium is missing
• in contrast, the surrounding mesenchyme and cartilage appear correctly developed


Mouse Genome Informatics
ht5
    Six1tm1Mair/Six1+
either: (involves: 129/Sv) or (involves: 129/Sv * C57BL/6J)
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
hearing/vestibular/ear
• at E16.5, 4 of 22 heterozygous ears (in 3 of 11 embryos) display slightly shortened cochlea by latex paintfilling
• the middle ear space is small and partially filled with loose connective tissue, probably due to secondary inflammation
• although the footplates of the stapes are seated in the oval window, the stapes has a small lumen
• stapedial arteries are absent in 4 cases from 3 heterozygous animals
• on a 129/Sv background, 8 of 13 heterozygotes show severe bilateral hearing loss (threshold shifted by 50 dB between 15 and 32 kHz), 2 of 13 mice show mild bilateral hearing loss (threshold shifted by 20 dB), whereas the remaining 3 mice have normal hearing in the right ears and >70 dB loss in the left ears
• most heterozygotes exhibit some degree of conductive hearing loss; variable among mice and ears
• all affected heterozygotes show a failure of the middle ear ossicles to complete a sound transmission path from the tympanum to the oval window
• on a 129/Sv background, 3 of 13 heterozygotes display normal hearing in the right ears and >70 dB loss in the left ears

nervous system
• in heterozygotes, the VIIth nerve passes abnormally close to the oval window and the stapes or fills up the middle ear space near the oval window

cardiovascular system
• stapedial arteries are absent in 4 cases from 3 heterozygous animals

craniofacial
• although the footplates of the stapes are seated in the oval window, the stapes has a small lumen
• stapedial arteries are absent in 4 cases from 3 heterozygous animals

skeleton
• although the footplates of the stapes are seated in the oval window, the stapes has a small lumen
• stapedial arteries are absent in 4 cases from 3 heterozygous animals


Mouse Genome Informatics
ht6
    Six1tm1Mair/Six1+
involves: 129 * C57BL/6J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
hearing/vestibular/ear
• at E17.5, 6 of 20 heterozygous mutant cochleae (4 of 10 embryos) coil between 1.5 and 1.75 turns
• at E17.5, only 1 of 20 heterozygous mutant sacculae (1 of 10 embryos) is malformed
• at E17.5, 2 of 20 heterozygous mutant inner ears (2 of 10 embryos) display a truncated endolymphatic duct/sac


Mouse Genome Informatics
cx7
    Six1tm1Mair/Six1tm1Mair
Six4tm1Mair/Six4tm1Mair

either: 129/Sv-Six1tm1Mair Six4tm1Mair or B6N.129-Six1tm1Mair Six4tm1Mair
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
mortality/aging
• double homozygotes die at birth

skeleton
• the temporal bone is reduced
• the orbits are small
• the mandible is extremely short
• the palatal process is absent
• absent nasal bone
• no ribs attach to the sternum
• distal ribs are reduced to small protrusions

muscle
• muscle progenitor cells fail to migrate into the limbs
• most ventral muscles are missing
• back muscles at the forelimb level and more rostrally are abnormally shaped, while those at the interlimb and hindlimb level are not as severely affected
• the genioglassal muscle in the head is absent
• the intrinsic tongue muscle is reduced at E18.5
• all muscles of the distal forelimb and hindlimb are absent
• all muscles of the proximal limbs are absent
• hypaxial muscle at the trunk level is severely diminished
• severe muscle hypoplasia is evident at E13.5 in the forelimbs with a total absence of myogenic cells in the limbs
• at E13.5, myogenic cell are absent from the abdominal region
• at E13.5, most muscles are lacking at the eye level and in the tongue; however, most head muscles are present at E18.5

hearing/vestibular/ear
• mutants are earless
• inner ear cartilage is absent
• the ectotympanic bone is missing

growth/size/body
• the palatal process is absent
• the intrinsic tongue muscle is reduced at E18.5
• mutants are earless

limbs/digits/tail
• abnormally bent forelimbs
• abnormally bent hindlimbs

behavior/neurological

vision/eye
• the orbits are small

craniofacial
• the temporal bone is reduced
• the orbits are small
• the mandible is extremely short
• the palatal process is absent
• absent nasal bone
• the intrinsic tongue muscle is reduced at E18.5
• mutants are earless

embryogenesis

digestive/alimentary system
• the palatal process is absent
• the intrinsic tongue muscle is reduced at E18.5

cellular
• muscle progenitor cells fail to migrate into the limbs


Mouse Genome Informatics
cx8
    Six1tm1Mair/Six1tm1Mair
Tbx1tm1Bem/Tbx1tm1Bem

involves: 129 * C57BL/6 * CD-1 * SJL
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
cardiovascular system
• about 63% of embryos show cardiovascular defects at E17.5


Mouse Genome Informatics
cx9
    Eya1tm1Rilm/Eya1+
Six1tm1Mair/Six1+

involves: 129/Sv * 129S1/Sv * 129X1/SvJ
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
renal/urinary system
• unilateral (6/21) or bilateral (9/21) kidney hypoplasia was seen on a 129 background
• Background Sensitivity: hypoplasia is more severe on a 129 background than on a C57BL/6 background
• bilateral (5/21) kidney agenesis was seen on a 129 background
• unilateral (1/21) kidney agenesis was seen on a 129 background
• the number of ureteric bud branches are decreased at E13.5


Mouse Genome Informatics
cx10
    Eya1tm1Rilm/Eya1+
Six1tm1Mair/Six1+

involves: 129/Sv * 129S1/Sv * 129X1/SvJ * C57BL/6
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
renal/urinary system
• unilateral (6/14) or bilateral (4/14) kidney hypoplasia was seen on a C57BL/6 background
• Background Sensitivity: hypoplasia is more severe on a 129 background than on a C57BL/6 background
• unilateral (4/10) kidney agenesis was seen on a C57BL/6 background
• the number of ureteric bud branches is decreased at E13.5


Mouse Genome Informatics
cx11
    Eya1tm1Rilm/Eya1+
Six1tm1Mair/Six1+

involves: 129/Sv * 129S1/Sv * 129X1/SvJ * C57BL/6J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
hearing/vestibular/ear
• at E17.5, double heterozygotes display an enhanced inner ear phenotype relative to each single heterozygous mutant animal
• at E17.5, 4 of 20 double heterozygous mutant inner ears (4 of 10 embryos) display a malformed cochlea
• at E17.5, 6 of 20 double heterozygous mutant cochleae (4 of 10 embryos) coil between 1.5 to 1.75 turns, 4 of 20 cochleae (3 of 10 embryos) coil between 1.25 and 1.5 turns, 5 of 20 cochlea (4 of 10 embryos) coil between 1.0 and 1.25 turns, and 4 of 20 cochleae (3 of 10 embryos) coil less than 1.0 turn
• at E17.5, 2 of 20 double heterozygous mutant inner ears (1 of 10 embryos) display a small lateral semicircular canal
• at E17.5, 2 of 20 double heterozygous mutant inner ears (1 of 10 embryos) display a truncated posterior semicircular canal
• at E17.5, 9 of 20 double heterozygous mutant inner ears (5 of 10 embryos) display significantly smaller posterior ampullae while 2 of 20 (1 of 10 embryos) lack posterior ampullae
• at E17.5, 11 of 20 double heterozygous mutant inner ears (6 of 10 embryos) display significantly smaller anterior ampullae
• at E17.5, 11 of 20 double heterozygous mutant inner ears (6 of 10 embryos) display significantly smaller lateral ampullae
• at E17.5, 2 of 20 double heterozygous mutant inner ears (1 of 10 embryos) display a small anterior semicircular canal
• at E17.5, 2 of 20 double heterozygous mutant inner ears (1 of 10 embryos) display smaller or malshaped sacculae
• at E17.5, 3 of 20 double heterozygous mutant inner ears (2 of 10 embryos) display a truncated endolymphatic duct/sac


Mouse Genome Informatics
cx12
    Eya1tm1Rilm/Eya1+
Pax2tm1Pgr/Pax2+
Six1tm1Mair/Six1+

involves: 129/Sv * 129S1/Sv * 129X1/SvJ * C57BL/6J
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
hearing/vestibular/ear
• at E17.5, 8 of 8 triple heterozygous mutant inner ears (from all 4 embryos) display a severely malformed cochlea with severely malformed distal tips
• at E17.5, 1 of 8 triple heterozygous mutant cochleae (1 of 4 embryos) coil between 1.0 and 1.25 turns, and 7 of 8 cochleae (4 of 4 embryos) coil less than 1.0 turn
• within the semicircular canals, a narrower lumen is observed in some areas
• at E17.5, 8 of 8 triple heterozygous mutant inner ears (from all 4 embryos) display a small lateral semicircular canal
• at E17.5, 4 of 8 triple heterozygous mutant inner ears (3 of 4 embryos) display a small posterior semicircular canal while 4 of 8 (3 of 4 embryos) show a truncated posterior semicircular canal
• at E17.5, 4 of 8 triple heterozygous mutant inner ears (3 of 4 embryos) display significantly smaller posterior ampullae while 4 of 8 ears (3 of 4 embryos) lack posterior ampullae
• at E17.5, 4 of 8 triple heterozygous mutant inner ears (from all 4 embryos) display significantly smaller anterior ampullae
• at E17.5, 4 of 8 triple heterozygous mutant inner ears (from all 4 embryos) display significantly smaller lateral ampullae
• at E17.5, 8 of 8 triple heterozygous mutant inner ears (from all 4 embryos) display a small anterior semicircular canal
• at E17.5, 8 of 8 triple heterozygous mutant inner ears (from all 4 embryos) display a small or malformed saccula
• at E17.5, 2 of 8 triple heterozygous mutant inner ears (1 of 4 embryos) display a truncated endolymphatic duct/sac


Mouse Genome Informatics
cx13
    Eya1tm1Rilm/Eya1tm1Rilm
Six1tm1Mair/Six1tm1Mair

involves: 129S1/Sv * 129X1/SvJ * C57BL/6
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
cardiovascular system
• 14% of embryos display right sided pulmonary artery (RPA) and right-sided aortic arch (RAA) together
• type B observed in 29% of embryos
• observed in 43% of embryos
• in 29% of embryos
• 100% of double homozygotes display outflow tract defects; most show multiple abnormalities
• about 70% of embryos have a single unseptated outflow vessel, with outflow valve containing 3 or 4 leaflets
• observed in 72% of embryos
• observed in 14% of embryos

craniofacial
• embryos display more severe craniofacial defects than single Six1- or Eya1-deficient homozygotes
• muscles of facial expression are hypoplastic
• tongue muscle is hypoplastic

muscle
• embryos have severely hypolplastic branchiomeric muscles
• tongue muscle is hypoplastic
• muscles are hypoplastic

cellular
• increased numbers of apoptotic cells are detected in the secondary heart field pharyngeal ectoderm and endoderm relative to controls
• apoptosis in pharyngeal mesenchymal cells derived from mesoderm or neural crest is significantly increased
• cell numbers in pharyngeal arches and outflow tracts are reduced relative to controls

digestive/alimentary system
• tongue muscle is hypoplastic

vision/eye
• muscles are hypoplastic

growth/size/body
• muscles of facial expression are hypoplastic
• tongue muscle is hypoplastic


Mouse Genome Informatics
cx14
    Eya1tm1Rilm/Eya1tm1Rilm
Six1tm1Mair/Six1+

involves: 129S1/Sv * 129X1/SvJ * C57BL/6
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
cardiovascular system
• observed in 44% of embryos
• observed in 56% of embryos
• observed in 11% of embryos
• 100% of compound mutants display outflow tract defects; most show multiple abnormalities
• observed in 33% of embryos


Mouse Genome Informatics
cx15
    Eya1tm1Rilm/Eya1+
Six1tm1Mair/Six1tm1Mair

involves: 129S1/Sv * 129X1/SvJ * C57BL/6
Key:
phenotype observed in females WTSI Wellcome Trust Sanger Institute
phenotype observed in males EuPh Europhenome
N normal phenotype
cardiovascular system
• observed in 20% of embryos
• type B observed in 33%
• 13% of embryos display duplicated left common carotid artery
• 87% of compound mutants display outflow tract defects
• observed in 13% of embryos