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Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Glrbspa
spastic
MGI:1856363
Summary 6 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Glrbspa/Glrbspa B6C3Fe a/a-Glrbspa/J MGI:3581146
hm2
Glrbspa/Glrbspa involves: C3HeB/FeLe * C57BL/6 * C57BL/6J * DBA/2 MGI:5086229
hm3
Glrbspa/Glrbspa Not Specified MGI:3695037
ht4
Glrbspa/Glrb+ B6C3Fe a/a-Glrbspa/J MGI:3622189
cx5
Glrbspa/Glrbspa
Tg(Eno2-Glrb)456Wha/Tg(Eno2-Glrb)456Wha
involves: C3HeB/FeLe * C57BL/6 * C57BL/6J * DBA/2 MGI:5086227
cx6
Glrbspa/Glrbspa
Tg(Eno2-Glrb)456Wha/0
involves: C3HeB/FeLe * C57BL/6 * C57BL/6J * DBA/2 MGI:5086228


Genotype
MGI:3581146
hm1
Allelic
Composition
Glrbspa/Glrbspa
Genetic
Background
B6C3Fe a/a-Glrbspa/J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Glrbspa mutation (2 available); any Glrb mutation (25 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
reproductive system
• in mutants, the zona pellucida-initiated acrosome reaction is significantly decreased compared to wild-type
• the zona pellucida-initiated acrosome reaction is significantly decreased compared to wild-type




Genotype
MGI:5086229
hm2
Allelic
Composition
Glrbspa/Glrbspa
Genetic
Background
involves: C3HeB/FeLe * C57BL/6 * C57BL/6J * DBA/2
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Glrbspa mutation (2 available); any Glrb mutation (25 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
reproductive system

behavior/neurological
• in all mice
• at 14 to 17 days old

muscle




Genotype
MGI:3695037
hm3
Allelic
Composition
Glrbspa/Glrbspa
Genetic
Background
Not Specified
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Glrbspa mutation (2 available); any Glrb mutation (25 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• percentage of mortality is high before or around weaning, although some can live almost a normal life span

muscle
• suffer from periods of spasticity which vary in length from one to several minutes; they walk in short steps, on tip-toe and arch their backs (J:5196)
• spasticity is induced by sudden handling (J:5196)
• sudden disturbance or handling causes spasms in which the back is stiff and arched, the legs are stiff and stretched, and the toes are extended (J:13079)
• when held by their tails, backs become stiff and bodies and legs quiver with a high frequency of vibration (J:13079)
• mutants are recognizeable by 14 days of age (J:13079)

behavior/neurological
• during a spasm, have great difficulty in turning over after being laid on the table with the belly facing upward
• exhibit increased startle responses to acoustic stimuli of different intensities
• when lifted up by the tail, backs stiffen and the entire body and legs quiver violently, indicating tremor
• lack facility in swimming
• in severe cases of spasms, mutants are arch-backed and slide on the table
• walk on tip-toe during a stimulus-induced spasm
• walk in short steps during a stimulus-induced spasm
• females produce young but are poor mothers, possibly because of physical difficulties

reproductive system
• frequency of litters from abnormal males is much lower

skeleton
• vertebral column abnormalities, with the lumbar region most severely affected, that include intervertebral enchondrosis, hyperplasia of fibrocartilage, and intervertebral arthrosis, probably resulting from disc herniations and ossification
• as early as 24 days of age, exhibit formation of leptomeningeal cysts in the vertebral column, usually located medial to spinal nerve roots
• cysts are lined with a single or multiple layer of cuboidal epithelium and filled with a mucoid fluid and cellular debris and are located between the dura and the spinal cord
• the dorsal longitudinal ligament is thinner dorsally than medially
• in older mutants, the mucoid material ossifies and adheres to the spinal meninges
• acute or subacute disc herniations; rupture of the annulus fibrosus leading to extrusion of the nucleus pulposus
• herniations of the nucleus pulposus are always dorsal or dorsolateral rather than medially
• skeleton becomes brittle with increasing age

nervous system
• occasionally Purkinje cells are lost
• as cysts become distended with fluid, the dura is displaced laterally against the wall of the vertebral canal
• necrobiotic changes involve the neurons of the spinal ganglia with certain of these calcifying and many have eccentric nuclei
• compression of the spinal roots by leptomeningeal cysts, leading to impingment of spinal root axons
• nerve fiber myelin and axonal changes occur in spinal roots, spinal nerves, cauda equina, and sciatic nerves
• disc protrusions indent the ventral aspects of the spinal cord; indentations are often deep enough to alter the normal shape and symmetry of the spinal cord both in the white and grey matter
• white matter atrophies at the sites of compression
• ventral horn neurons become flattened or stretched due to the compression of the spinal cord and undergo degenerative changes, such as shrinkage, vacuolation, and necrobiosis

cardiovascular system
• disk herniations cause hemorrhage

endocrine/exocrine glands
• adrenal corticism is more evident in older mutants, beginning at about 2 months of age
• enlarged due to cortical hypertrophy and hyperplasia

growth/size/body

homeostasis/metabolism
• disc herniations cause edema

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
hyperekplexia 2 DOID:0060697 OMIM:614619
J:33924




Genotype
MGI:3622189
ht4
Allelic
Composition
Glrbspa/Glrb+
Genetic
Background
B6C3Fe a/a-Glrbspa/J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Glrbspa mutation (2 available); any Glrb mutation (25 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
reproductive system
• in mutants, the zona pellucida-initiated acrosome reaction is significantly decreased compared to wild-type
• the zona pellucida-initiated acrosome reaction is significantly decreased compared to wild-type




Genotype
MGI:5086227
cx5
Allelic
Composition
Glrbspa/Glrbspa
Tg(Eno2-Glrb)456Wha/Tg(Eno2-Glrb)456Wha
Genetic
Background
involves: C3HeB/FeLe * C57BL/6 * C57BL/6J * DBA/2
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Glrbspa mutation (2 available); any Glrb mutation (25 available)
Tg(Eno2-Glrb)456Wha mutation (0 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
reproductive system
N
• male mice exhibit normal fertility unlike Glrbspa homozygotes

behavior/neurological
• in 14% of mice compared with 100% of Glrbspa homozygotes
• in 32% of mice compared with 100% of Glrbspa homozygotes
• between 2 and 10 days, mice exhibit transient handling-induced tremors
• after 20 to 35 days, mice exhibit tremors that are less strong than in Glrbspa homozygotes




Genotype
MGI:5086228
cx6
Allelic
Composition
Glrbspa/Glrbspa
Tg(Eno2-Glrb)456Wha/0
Genetic
Background
involves: C3HeB/FeLe * C57BL/6 * C57BL/6J * DBA/2
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Glrbspa mutation (2 available); any Glrb mutation (25 available)
Tg(Eno2-Glrb)456Wha mutation (0 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
reproductive system
• not as severe as in Glrbspa homozygotes

behavior/neurological
• in 52% of mice compared with 100% of Glrbspa homozygotes
• in 71% of mice compared with 100% of Glrbspa homozygotes
• at 14 to 17 days old

muscle
• mice exhibit a less severe spastic phenotype compared with Glrbspa homozygotes





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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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last database update
06/28/2022
MGI 6.20
The Jackson Laboratory