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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID 		Tubb4bem1(IMPC)J
endonuclease-mediated mutation 1, Jackson
MGI:6120520
Summary 3 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
 		Tubb4bem1(IMPC)J/Tubb4bem1(IMPC)J C57BL/6NJ-Tubb4bem1(IMPC)J/Mmjax MGI:6394409
hm2
 		Tubb4bem1(IMPC)J/Tubb4bem1(IMPC)J involves: 129S/SvEv * C57BL/6NJ MGI:8319153
ht3
 		Tubb4bem1(IMPC)J/Tubb4b+ C57BL/6NJ-Tubb4bem1(IMPC)J/Mmjax MGI:6288806


Genotype
MGI:6394409
hm1
Allelic
Composition		 Tubb4bem1(IMPC)J/Tubb4bem1(IMPC)J
Genetic
Background		 C57BL/6NJ-Tubb4bem1(IMPC)J/Mmjax
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tubb4bem1(IMPC)J mutation (2 available); any Tubb4b mutation (15 available)
Data Sources
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
mortality/aging




Genotype
MGI:8319153
hm2
Allelic
Composition		 Tubb4bem1(IMPC)J/Tubb4bem1(IMPC)J
Genetic
Background		 involves: 129S/SvEv * C57BL/6NJ
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tubb4bem1(IMPC)J mutation (2 available); any Tubb4b mutation (15 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
hearing/vestibular/ear
hearing/vestibular/ear phenotype ( J:354347 )
N
• normal hair cell and organ of Corti morphology
• normal kinocilia morphology
• normal stereocilia bundle morphology
abnormal Deiters cell morphology ( J:354347 )
• narrow phalangeal processes and microtubule stalk
• normal cup diameter
abnormal pillar cell morphology ( J:354347 )
• reduced head length

cellular
abnormal motile cilium morphology ( J:354347 )
• shorter and fewer motile cilia in middle ear near Eustachian tube and in dorsal region at age P10 and in adults
azoospermia ( J:354352 )
• no sperm cells in testes and cauda epididymis
abnormal spermatocyte morphology ( J:354352 )
• no meiotic cells in seminiferous tubules at age P15
• apoptotic cells in seminiferous tubules at age P15

immune system

endocrine/exocrine glands
seminiferous tubule degeneration ( J:354352 )
• at age P15
• normal at age P6
decreased testis weight ( J:354352 )
• at age P10
• normal at age P6

reproductive system
azoospermia ( J:354352 )
• no sperm cells in testes and cauda epididymis
abnormal spermatocyte morphology ( J:354352 )
• no meiotic cells in seminiferous tubules at age P15
• apoptotic cells in seminiferous tubules at age P15
seminiferous tubule degeneration ( J:354352 )
• at age P15
• normal at age P6
decreased testis weight ( J:354352 )
• at age P10
• normal at age P6

nervous system
nervous system phenotype ( J:354347 )
N
• normal ribbon synapse morphology
• normal spiral ganglion morphology

vision/eye
vision/eye phenotype ( J:354347 )
N
• normal ERG responses




Genotype
MGI:6288806
ht3
Allelic
Composition		 Tubb4bem1(IMPC)J/Tubb4b+
Genetic
Background		 C57BL/6NJ-Tubb4bem1(IMPC)J/Mmjax
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Tubb4bem1(IMPC)J mutation (2 available); any Tubb4b mutation (15 available)
Data Sources
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
integument




Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
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Send questions and comments to User Support. 		last database update
04/14/2026
MGI 6.24 		The Jackson Laboratory