Phenotypes Associated with This Genotype

Genotype
MGI:3695936

• Allelic Composition: Gata3^tm2Gsv/Gata3^tm2Gsv
• Genetic Background: either: (involves: 129P2/OlaHsd * C57BL/6) or (involves: 129S7/SvEvBrd * C57BL/6)

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

mortality/aging

embryonic lethality during organogenesis, complete penetrance ( J:66227 )

• homozygotes occasionally survive to E10.5, with a few surviving up to E13.5

hearing/vestibular/ear

abnormal otic vesicle development ( J:66227 )

• at E13.5, homozygotes exhibit a variable degree of otocyst formation, with 2 of 4 mutants found arrested at an earlier otocyst stage (E10.5)

• however, all sensory epithelia can be tentatively identified in remaining two (least severe) cases

small otic vesicle ( J:66227 )

• at E11.5, homozygotes display a much smaller invaginating otocyst relative to heterozygotes; however, the ectodermal patch of tissue anterior to the otocyst appears larger

abnormal inner ear morphology ( J:66227 )

• inner ear morphogenesis and growth is severely inhibited after initial otic vesicle formation

inner ear cyst ( J:66227 )

• at E13.5, the entire inner ear appears as an elongated cyst, with a single extension of the endolymphatic duct observed in more developmentally advanced mutants

delayed inner ear development ( J:66227 )

abnormal cochlear sensory epithelium morphology ( J:66227 )

• homozygotes display a severe reduction of cochlear sensory neuron formation

decreased cochlea coiling ( J:66227 )

• at E13.5, developmentally advanced homozygotes display a cochlea with a single ventral extension rather than one turn, suggesting reduced cochlear outgrowth

absent common crus ( J:66227 )

• at E13.5, the common crus of the anterior and posterior canal is absent

absent semicircular canals ( J:66227 )

• at E13.5, the three semicircular canals are absent

absent utricle ( J:66227 )

• at E13.5, no utricular recess is formed

absent vestibular saccule ( J:66227 )

• at E13.5, no saccular recess is formed

abnormal endolymphatic duct morphology ( J:66227 )

• at E13.5, less severely affected homozygotes display a single recess coming out of the otocyst, which is interpreted as the endolymphatic duct

nervous system

abnormal axon guidance ( J:66227 )

• homozygotes exhibit abnormal axonal navigation of the inner ear efferent neurons

abnormal sensory neuron innervation pattern ( J:66227 )

• homozygotes display aberrant inner ear efferent axonal projections, such as projections of fibers through the facial branchial motor nerve root, and caudal extension of efferent axons along the floor plate midline into r5 and occasionally into r6, not seen in wild-type littermates

cellular

abnormal axon guidance ( J:66227 )

• homozygotes exhibit abnormal axonal navigation of the inner ear efferent neurons

growth/size/body

inner ear cyst ( J:66227 )

• at E13.5, the entire inner ear appears as an elongated cyst, with a single extension of the endolymphatic duct observed in more developmentally advanced mutants