About   Help   FAQ
Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Fosbtm1Meg
targeted mutation 1, Michael E Greenburg
MGI:1857395
Summary 4 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Fosbtm1Meg/Fosbtm1Meg either: (involves: 129S4/SvJae * 129X1/SvJ) or (involves: 129S4/SvJae * 129X1/SvJ * BALB/c) MGI:3653349
hm2
Fosbtm1Meg/Fosbtm1Meg involves: 129S4/SvJae * 129X1/SvJ MGI:3653339
hm3
Fosbtm1Meg/Fosbtm1Meg involves: 129S4/SvJae * 129X1/SvJ * BALB/c MGI:3653352
ht4
Fosbtm1Meg/Fosb+ involves: 129S4/SvJae * 129X1/SvJ * BALB/c MGI:3653353


Genotype
MGI:3653349
hm1
Allelic
Composition
Fosbtm1Meg/Fosbtm1Meg
Genetic
Background
either: (involves: 129S4/SvJae * 129X1/SvJ) or (involves: 129S4/SvJae * 129X1/SvJ * BALB/c)
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fosbtm1Meg mutation (1 available); any Fosb mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• young homozygous males display defective nurturing behavior illustrated by impaired pup retrieval compared to wild-type males
• majority of pups die within 1 to 2 days of birth regardless of their genotype
• homozygous pups will survive if fostered by wild-type or heterozygous females
• Background Sensitivity: if homozygous females are mated to homozygous, heterozygous or wild-type males on a 129 background, 0-1 pups on average survive to weaning regardless of pup genotype; if homozygous males are mated to heterozygous or wild-type females, 3-5 pups survive to weaning regardless of pup genotype
• Background Sensitivity: if homozygous females are mated to homozygous, heterozygous or wild-type males on 129/B6 background, only 1-2 pups survive to weaning regardless of pup genotype; if homozygous males are mated to heterozygous or wild-type females, 7-9 pups survive to weaning regardless of genotype
• homozygous females do not nurse their pups
• if 3 pups are removed from the cage then replaced shortly after, homozygous females take 50 times longer to retrieve the first pup compared to wild-type or heterozygotes and only 50% retrieve even one pup

growth/size/body
• homozygotes are about ~10% smaller than wild-type




Genotype
MGI:3653339
hm2
Allelic
Composition
Fosbtm1Meg/Fosbtm1Meg
Genetic
Background
involves: 129S4/SvJae * 129X1/SvJ
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fosbtm1Meg mutation (1 available); any Fosb mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• 2-3 month old mutant mice show a significant delay in development of tolerance to motor seizures compared to wild-type mice; repeated ECS treatment does eventually result in a significant reduction in seizure duration, to wild-type levels by day 6 of treatment

nervous system
• 2-3 month old mutant mice show a significant delay in development of tolerance to motor seizures compared to wild-type mice; repeated ECS treatment does eventually result in a significant reduction in seizure duration, to wild-type levels by day 6 of treatment
• in layer II/III pyramidal cells, repeated ECS treatments does not alter 25 um NMDA-induced inward current but currents in wild-type cells are significantly enhanced in brain slices from 2-3 month old mutants




Genotype
MGI:3653352
hm3
Allelic
Composition
Fosbtm1Meg/Fosbtm1Meg
Genetic
Background
involves: 129S4/SvJae * 129X1/SvJ * BALB/c
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fosbtm1Meg mutation (1 available); any Fosb mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• mutants display a significant decrease (41.5%) in REM sleep during lights-on periods; there is a significant decrease (31.5%) in REM sleep during the lights-out period compared to wild-type




Genotype
MGI:3653353
ht4
Allelic
Composition
Fosbtm1Meg/Fosb+
Genetic
Background
involves: 129S4/SvJae * 129X1/SvJ * BALB/c
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Fosbtm1Meg mutation (1 available); any Fosb mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• mice show fewer numbers of REM sleep bouts than wild-type





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)
Citing These Resources
Funding Information
Warranty Disclaimer, Privacy Notice, Licensing, & Copyright
Send questions and comments to User Support.
last database update
10/29/2024
MGI 6.24
The Jackson Laboratory