About   Help   FAQ
Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Chrnb4tm1Mdb
targeted mutation 1, Mariella De Biasi
MGI:2158716
Summary 4 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Chrnb4tm1Mdb/Chrnb4tm1Mdb B6.129-Chrnb4tm1Mdb MGI:3042857
hm2
Chrnb4tm1Mdb/Chrnb4tm1Mdb involves: 129S7/SvEvBrd * C57BL/6J MGI:2663178
cx3
Chrna5tm1Mdb/Chrna5tm1Mdb
Chrnb4tm1Mdb/Chrnb4tm1Mdb
B6.129-Chrnb4tm1Mdb Chrna5tm1Mdb MGI:3042858
cx4
Chrnb2tm1Mdb/Chrnb2tm1Mdb
Chrnb4tm1Mdb/Chrnb4tm1Mdb
involves: 129S7/SvEvBrd * C57BL/6J MGI:2663179


Genotype
MGI:3042857
hm1
Allelic
Composition
Chrnb4tm1Mdb/Chrnb4tm1Mdb
Genetic
Background
B6.129-Chrnb4tm1Mdb
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Chrnb4tm1Mdb mutation (2 available); any Chrnb4 mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• less sensitivity to nicotine-induced seizures than wild-type controls or Chrna5tm1Mdb/tm1Mdb mice

nervous system
• less sensitivity to nicotine-induced seizures than wild-type controls or Chrna5tm1Mdb/tm1Mdb mice




Genotype
MGI:2663178
hm2
Allelic
Composition
Chrnb4tm1Mdb/Chrnb4tm1Mdb
Genetic
Background
involves: 129S7/SvEvBrd * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Chrnb4tm1Mdb mutation (2 available); any Chrnb4 mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
renal/urinary system
• focal hyperplasia or dysplasia is noted in 3 of 4 animals and mitotic activity in 2 of 4 animals
• in response to nicotine, contraction in bladder strips was greatly reduced whereas contraction was easily induced in controls (J:73590)
• contractile responses to nicotine in bladder strips from 2- to 5-day-old mutant mice are severely attenuated, despite the absence of bladder distension and urine retention phenotype seen in Chrna3 mutant mice (J:102601)




Genotype
MGI:3042858
cx3
Allelic
Composition
Chrna5tm1Mdb/Chrna5tm1Mdb
Chrnb4tm1Mdb/Chrnb4tm1Mdb
Genetic
Background
B6.129-Chrnb4tm1Mdb Chrna5tm1Mdb
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Chrna5tm1Mdb mutation (2 available); any Chrna5 mutation (38 available)
Chrnb4tm1Mdb mutation (2 available); any Chrnb4 mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
behavior/neurological
• less sensitive to nicotine-induced seizures than wild-type controls or single homozygous mutant mice
• latency time to seizure is significantly shorter than in wild-type

nervous system
• less sensitive to nicotine-induced seizures than wild-type controls or single homozygous mutant mice
• latency time to seizure is significantly shorter than in wild-type




Genotype
MGI:2663179
cx4
Allelic
Composition
Chrnb2tm1Mdb/Chrnb2tm1Mdb
Chrnb4tm1Mdb/Chrnb4tm1Mdb
Genetic
Background
involves: 129S7/SvEvBrd * C57BL/6J
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Chrnb2tm1Mdb mutation (1 available); any Chrnb2 mutation (32 available)
Chrnb4tm1Mdb mutation (2 available); any Chrnb4 mutation (22 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• most homozygous animals die within 10 days of birth and the remainder die by 3 weeks of age

growth/size/body
• delayed opening and flattening of the ears after birth
• growth is significantly impaired compared to controls

homeostasis/metabolism
N
• blood chemistry measurments for glucose, electrolytes, phosphate, calcium, magnesium, urea nitrogen, creatinine, alanine aminotransferase, aspartate aminotransferase, and bilirubin are similar to controls
• urine chemistry measurments for glucose, electrolytes, phosphate, calcium, magnesium, and creatinine are similar to controls

immune system
• inflamed urinary bladder
• urine is sometimes cloudy with a dense accumulation of bacteria and white blood cells

behavior/neurological
• no contraction in response to light

muscle
N
• smooth muscle contraction in the urinary bladder can be induced with the muscarinic agonist CCH suggesting normal muscle function
• reduced intestinal motility

nervous system
• profiles of current recordings from nicotine-elicited superior cervial ganglion neurons show no that nicotine does not elicit inward currents at any concentration tested, wheras robust inward currents are seen in controls
• profiles of current recordings from nicotine-elicited superior cervial ganglion neurons show no that nicotine does not elicit inward currents at any concentration tested, wheras robust inward currents are seen in controls

renal/urinary system
• necrotic mucosa observed in 3 of 4 mice examined
• bladder mucosa was dysplastic with malignant characteristics in 2 of 4 mice examined
• in older animals, the bladder often contains numerous urinary stones
• distended bladders are seen in 3 of 7 mice
• nicotine failed to elicit contraction in bladder strips whereas contraction was easily induced in controls (J:73590)
• contractile responses to nicotine in bladder strips from 2- to 5-day-old mutant mice are severely attenuated (J:102601)
• inflamed urinary bladder
• wetness of the genital area is noted; chronic urinary dribbling is observed throughout life

vision/eye
• no contraction in response to light
• widely dilated ocular pupils
• small palpebral fissures
• eyes remain closed after postnatal day 15

craniofacial
• delayed opening and flattening of the ears after birth

hearing/vestibular/ear
• delayed opening and flattening of the ears after birth

digestive/alimentary system
• reduced intestinal motility

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)
Citing These Resources
Funding Information
Warranty Disclaimer, Privacy Notice, Licensing, & Copyright
Send questions and comments to User Support.
last database update
04/30/2024
MGI 6.23
The Jackson Laboratory