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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID 		Or8a1b+
wild type
MGI:2441112
Summary 12 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
cx1
 		Ebf2tm3.1(Zfp423*)Reed/Ebf2+
Or8a1btm4Mom/Or8a1b+ 		involves: 129 * 129P2/OlaHsd * C57BL/10J MGI:5461571
cx2
 		Or8a1btm4Mom/Or8a1b+
Ttc8tm1Reed/Ttc8tm1Reed 		involves: 129 * 129P2/OlaHsd * C57BL/6 MGI:5140727
cx3
 		Ebf2tm1Reed/Ebf2+
Or8a1btm4Mom/Or8a1b+ 		involves: 129P2/OlaHsd * 129S1/Sv * 129X1/SvJ MGI:3714645
cx4
 		Adcy3tm1Drs/Adcy3tm1Drs
Or8a1btm4Mom/Or8a1b+ 		involves: 129P2/OlaHsd * 129X1/SvJ * C57BL/6 MGI:3714866
cx5
 		Or8a1tm10Mom/Or8a1+
Or8a1btm4Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6 MGI:3694133
cx6
 		Or8a1tm1Mom/Or8a1+
Or8a1btm1(Or8a1)Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6 MGI:3694128
cx7
 		Or8a1tm11(Or8a1b)Mom/Or8a1+
Or8a1btm1(Or8a1)Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6 MGI:3694125
cx8
 		Or8a1tm2Mom/Or8a1+
Or8a1btm6Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6 MGI:3694130
cx9
 		Cnga2tm1Mom/Cnga2tm1Mom
Or8a1btm5(Cnga2)Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6J MGI:3718345
cx10
 		Cnga2tm1Mom/Y
Or8a1btm5(Cnga2)Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6J MGI:3718346
cx11
 		Cnga2tm1Mom/Cnga2tm1Mom
Or8a1btm4Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6J MGI:3718347
cx12
 		Cnga2tm1Mom/Y
Or8a1btm4Mom/Or8a1b+ 		involves: 129P2/OlaHsd * C57BL/6J MGI:3718349


Genotype
MGI:5461571
cx1
Allelic
Composition		 Ebf2tm3.1(Zfp423*)Reed/Ebf2+
Or8a1btm4Mom/Or8a1b+
Genetic
Background		 involves: 129 * 129P2/OlaHsd * C57BL/10J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Ebf2tm3.1(Zfp423*)Reed mutation (0 available); any Ebf2 mutation (32 available)
Or8a1btm4Mom mutation (1 available); any Or8a1b mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory sensory neuron morphology ( J:190934 )
• decrease in the number of labeled sensory neurons in the olfactory bulb
abnormal sensory neuron innervation pattern ( J:190934 )
• some labeled axons innervate aberrant extra glomeruli in the olfactory bulb

craniofacial
abnormal olfactory sensory neuron morphology ( J:190934 )
• decrease in the number of labeled sensory neurons in the olfactory bulb

respiratory system
abnormal olfactory sensory neuron morphology ( J:190934 )
• decrease in the number of labeled sensory neurons in the olfactory bulb

taste/olfaction
abnormal olfactory sensory neuron morphology ( J:190934 )
• decrease in the number of labeled sensory neurons in the olfactory bulb

growth/size/body
abnormal olfactory sensory neuron morphology ( J:190934 )
• decrease in the number of labeled sensory neurons in the olfactory bulb




Genotype
MGI:5140727
cx2
Allelic
Composition		 Or8a1btm4Mom/Or8a1b+
Ttc8tm1Reed/Ttc8tm1Reed
Genetic
Background		 involves: 129 * 129P2/OlaHsd * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Or8a1btm4Mom mutation (1 available); any Or8a1b mutation (35 available)
Ttc8tm1Reed mutation (0 available); any Ttc8 mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype

Olfactory sensory neurons axon targeting is perturbed in Ttc8tm1Reed/Ttc8tm1Reed Or8a1btm4Mom/Or8a1b+ mice

nervous system
abnormal axon fasciculation ( J:173465 )
• impaired fasiculation of olfactory sensory neuron axons
abnormal axon guidance ( J:173465 )
• unlike in controls where all labeled axons converge to a single, posterior glomerulus, multiple glomeruli are innervated by olfactory sensory neuron axons and individual "wandering" fibers are observed

cellular
abnormal axon fasciculation ( J:173465 )
• impaired fasiculation of olfactory sensory neuron axons
abnormal axon guidance ( J:173465 )
• unlike in controls where all labeled axons converge to a single, posterior glomerulus, multiple glomeruli are innervated by olfactory sensory neuron axons and individual "wandering" fibers are observed




Genotype
MGI:3714645
cx3
Allelic
Composition		 Ebf2tm1Reed/Ebf2+
Or8a1btm4Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * 129S1/Sv * 129X1/SvJ
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Ebf2tm1Reed mutation (0 available); any Ebf2 mutation (32 available)
Or8a1btm4Mom mutation (1 available); any Or8a1b mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory sensory neuron morphology ( J:122275 )
• most olfactory receptor neurons project to multiple more ventral glomeruli
• P2 olfactory receptor neurons extend much shorter axons and project into the ventral region of the bulb

craniofacial
abnormal olfactory sensory neuron morphology ( J:122275 )
• most olfactory receptor neurons project to multiple more ventral glomeruli
• P2 olfactory receptor neurons extend much shorter axons and project into the ventral region of the bulb

respiratory system
abnormal olfactory sensory neuron morphology ( J:122275 )
• most olfactory receptor neurons project to multiple more ventral glomeruli
• P2 olfactory receptor neurons extend much shorter axons and project into the ventral region of the bulb

taste/olfaction
abnormal olfactory sensory neuron morphology ( J:122275 )
• most olfactory receptor neurons project to multiple more ventral glomeruli
• P2 olfactory receptor neurons extend much shorter axons and project into the ventral region of the bulb

growth/size/body
abnormal olfactory sensory neuron morphology ( J:122275 )
• most olfactory receptor neurons project to multiple more ventral glomeruli
• P2 olfactory receptor neurons extend much shorter axons and project into the ventral region of the bulb




Genotype
MGI:3714866
cx4
Allelic
Composition		 Adcy3tm1Drs/Adcy3tm1Drs
Or8a1btm4Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * 129X1/SvJ * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Adcy3tm1Drs mutation (0 available); any Adcy3 mutation (45 available)
Or8a1btm4Mom mutation (1 available); any Or8a1b mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory bulb morphology ( J:122528 )
• glomeruli structure is irregular
abnormal olfactory nerve morphology ( J:122528 )
• on the median and lateral sides of the bulb, fewer Olfr160+ neurons form large glomeruli as in wild-type mice
• fewer Olfr160+ neurons are present (197+/-40 compared to 213+/-51 in wild-type mice)




Genotype
MGI:3694133
cx5
Allelic
Composition		 Or8a1tm10Mom/Or8a1+
Or8a1btm4Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Or8a1btm4Mom mutation (1 available); any Or8a1b mutation (35 available)
Or8a1tm10Mom mutation (1 available); any Or8a1 mutation (69 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory bulb morphology ( J:90716 )
• Hyb J axons form distinct glomeruli that are not Olfr151 or Olfr160 in character
abnormal olfactory neuron innervation pattern ( J:90716 )
• Hyb J axons form distinct glomeruli that are not Olfr151 or Olfr160 in character




Genotype
MGI:3694128
cx6
Allelic
Composition		 Or8a1tm1Mom/Or8a1+
Or8a1btm1(Or8a1)Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Or8a1btm1(Or8a1)Mom mutation (3 available); any Or8a1b mutation (35 available)
Or8a1tm1Mom mutation (1 available); any Or8a1 mutation (69 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory bulb morphology ( J:90716 )
• Hyb A axons co-converge with Olfr160tm6Mom axons onto the same glomeruli, but axons segregate into separate compartments within the glomeruli




Genotype
MGI:3694125
cx7
Allelic
Composition		 Or8a1tm11(Or8a1b)Mom/Or8a1+
Or8a1btm1(Or8a1)Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Or8a1btm1(Or8a1)Mom mutation (3 available); any Or8a1b mutation (35 available)
Or8a1tm11(Or8a1b)Mom mutation (1 available); any Or8a1 mutation (69 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory bulb morphology ( J:90716 )
• Olfr160 (M72) glomeruli are positioned more posterior and medial to the corresponding glomeruli in control mice, while Olfr151 (M71) glomeruli are slightly more anterior and lateral to the normal location




Genotype
MGI:3694130
cx8
Allelic
Composition		 Or8a1tm2Mom/Or8a1+
Or8a1btm6Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Or8a1btm6Mom mutation (4 available); any Or8a1b mutation (35 available)
Or8a1tm2Mom mutation (1 available); any Or8a1 mutation (69 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory neuron innervation pattern ( J:90716 )
• Olfr151 and Olfr160 axons only intermingle to a small extent; atypical glomeruli are formed in which some co-mingling of Olfr151tm2Momaxons with both Olfr151 and Olfr160 axons occurs, but Olfr151tm2Momaxons are shared between glomeruli




Genotype
MGI:3718345
cx9
Allelic
Composition		 Cnga2tm1Mom/Cnga2tm1Mom
Or8a1btm5(Cnga2)Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Cnga2tm1Mom mutation (2 available); any Cnga2 mutation (14 available)
Or8a1btm5(Cnga2)Mom mutation (1 available); any Or8a1b mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
taste/olfaction
abnormal olfactory system physiology ( J:67661 )
• olfactory neurons are not responsive to forskolin

nervous system
abnormal neuron physiology ( J:67661 )
• olfactory neurons are not responsive to forskolin




Genotype
MGI:3718346
cx10
Allelic
Composition		 Cnga2tm1Mom/Y
Or8a1btm5(Cnga2)Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Cnga2tm1Mom mutation (2 available); any Cnga2 mutation (14 available)
Or8a1btm5(Cnga2)Mom mutation (1 available); any Or8a1b mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
taste/olfaction
abnormal olfactory system physiology ( J:67661 )
• olfactory neurons are not responsive to forskolin

nervous system
abnormal neuron physiology ( J:67661 )
• olfactory neurons are not responsive to forskolin




Genotype
MGI:3718347
cx11
Allelic
Composition		 Cnga2tm1Mom/Cnga2tm1Mom
Or8a1btm4Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Cnga2tm1Mom mutation (2 available); any Cnga2 mutation (14 available)
Or8a1btm4Mom mutation (1 available); any Or8a1b mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb
abnormal olfactory bulb morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• Olfr160+ glomeruli are localized more ventrally than in wild-type mice
• at day 7, extra minor glomeruli are observed
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or to continue to grow past the glomerulus layer into the deep layers of the bulb

craniofacial
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb

respiratory system
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb

taste/olfaction
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb

growth/size/body
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb




Genotype
MGI:3718349
cx12
Allelic
Composition		 Cnga2tm1Mom/Y
Or8a1btm4Mom/Or8a1b+
Genetic
Background		 involves: 129P2/OlaHsd * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Cnga2tm1Mom mutation (2 available); any Cnga2 mutation (14 available)
Or8a1btm4Mom mutation (1 available); any Or8a1b mutation (35 available)
♀ phenotype observed in females
♂ phenotype observed in males
N normal phenotype
nervous system
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb
abnormal olfactory bulb morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• Olfr160+ glomeruli are localized more ventrally than in wild-type mice
• at day 7, extra minor glomeruli are observed
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or to continue to grow past the glomerulus layer into the deep layers of the bulb

craniofacial
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb

respiratory system
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb

taste/olfaction
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb

growth/size/body
abnormal olfactory sensory neuron morphology ( J:67661 )
• mice have more and shorter olfactory neuron axonal projections per bulb (2-9 Olfr160+ glomeruli per bulb with a mean length of 41um compared to 2-4 Olfr160+ glomeruli per bulb with a mean length of 72 um in wild-type mice)
• at day 7, Olfr160+ axons are often observed to enter inappropriate glomeruli or continue to grow past the glomerulus layer into the deep layers of the bulb




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Send questions and comments to User Support. 		last database update
01/13/2026
MGI 6.24 		The Jackson Laboratory