Overview

These Slc12a2 (or Nkcc1) knockout mice exhibit growth retardation with a 30% incidence of death by the time of weaning. They are deaf, have less body fat, reduced mean arterial blood pressure, exhibit reduced cAMP-induced short circuit currents in jejunum, cecum, and trachea, unusual head postures, and engage in circling behaviors and rapid spinning, but have difficulty maintaining their balance. These mice may be useful for studying the regulation of cell volume, and the control of Cl- and K+ secretion in the maintenance of hearing and blood pressure.

Donating Investigator

Gary E Shull, University of Cincinnati

Genetic overview

Genetic Background	Generation

Slc12a2^tm1Ges

Allele Type	Gene Symbol	Gene Name
Targeted (Null/Knockout)	Slc12a2	solute carrier family 12, member 2

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Research Applications

Mouse/Human Gene Homologs
Developmental Biology Research
Cell Biology Research
Neurobiology Research
Sensorineural Research

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Details

Detailed Description

Homozygotes: A targeting vector was designed to insert a neomycin resistance (neo) cassette into exon 6 of the solute carrier family 12, member 2 (Slc12a2 or Nkcc1) gene, abolishing gene function. Homozygous mice are viable, fertile, and exhibit growth retardation with a 30% incidence of death by the time of weaning. Nkcc1 regulates cell volume and is expressed in vascular endothelial cells where it is required for controlling cytosolic concentrations of Cl^- and K⁺, and in the basolateral membranes of epithelial cells where it provides an entry pathway for ions that are secreted across the apical membrane. These Nkcc1^-/- mice are significantly smaller than their wildtype littermates by 1 week of age, and remain 80% smaller as adults. They are deaf, have less body fat, reduced mean arterial blood pressure, and exhibit reduced cAMP-induced short circuit currents in jejunum, cecum, and trachea. These mutant mice also demonstrate unusual head postures, and engage in circling behaviors and rapid spinning, but have difficulty maintaining their balance. The lumen of the cochlear duct of these mice is collapsed, and Reissner's membrane lies against the interdental cells of the spiral limbus, the tectorial membrane, and the stria vascularis. These mice may be useful for studying the regulation of cell volume, and the control of Cl^- and K⁺ secretion in the maintainance of hearing and blood pressure.

Heterozygote: Heterozygous mice are viable, fertile, and normal in size. They exhibit normal growth, and are phenotypically similar to wildtype mice with the exception of slightly reduced blood pressure.

Development

A targeting vector was designed to insert a neomycin resistance (neo) cassette into exon 6 of the solute carrier family 12, member 2 (Slc12a2 or Nkcc1) gene. The construct was electroporated into 129-derived embryonic stem (ES) cells and correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric males were bred to Black Swiss females, and these mice were subsequently backcrossed to FVB/N mice for at least 10 generations. Upon arrival at The Jackson Laboratory, mice were bred to FVB/NJ inbred mice for at least one generation to establish the colony.

Control Suggestions

Wild-type from the colony

Approximate Controls

001800 FVB/NJ

Additional Information

Considerations for Choosing Controls

Selected References

Flagella M; Clarke LL; Miller ML; Erway LC; Giannella RA; Andringa A; Gawenis LR; Kramer J; Duffy JJ; Doetschman T; Lorenz JN; Yamoah EN; Cardell EL; Shull GE. 1999. Mice lacking the basolateral Na-K-2Cl cotransporter have impaired epithelial chloride secretion and are profoundly deaf. J Biol Chem 274(38):26946-55PubMed: 10480906 MGI: J:57651

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Genetics

Slc12a2^tm1Ges

Allele Symbol: Slc12a2^tm1Ges

Allele Name	targeted mutation 1, Gary E Shull
Allele Type	Targeted (Null/Knockout)
Allele Synonym(s)	Nkcc1^-
Gene Symbol and Name	Slc12a2, solute carrier family 12, member 2
Gene Synonym(s)
Strain of Origin	129
Chromosome	18
Molecular Note	Insertion of a neomycin gene into exon 6. Northern blot analysis of brain, heart, skeletal muscle, lung, kidney, stomach, small intestine and colon failed to detect any mRNA in homozygous mutants.
Mutations Made By	Gary Shull, University of Cincinnati

Disease/Phenotype

Disease Terms

Research Areas By Phenotype

This mouse can be used to support research in many areas including:

Mouse/Human Gene Homologs
- deafness
Developmental Biology Research
- Growth Defects
  - Growth Defects (homozygous)
Cell Biology Research
- Channel and Transporter Defects
  - chloride
  - potassium
Neurobiology Research
- Channel and Transporter Defects
  - potassium
Sensorineural Research
- Hearing Defects

Mammalian Phenotype Terms by Genotype

The following phenotype information is associated with a similar, but not exact match to this JAX^® Mice strain

Genotype: Slc12a2^tm1Ges/Slc12a2^tm1Ges
Not Specified

adipose tissue phenotype

decreased total body fat amount

digestive/alimentary phenotype

abnormal intestine morphology
- in young mice; decreasing severity with age

remittent intestinal hemorrhage
- incomplete penetrance

decreased salivation

coiled cecum
- worm-like appearance

small intestinal prolapse

abnormal colon morphology
- frequent fecal blockage

endocrine/exocrine gland phenotype

decreased salivation

growth/size/body region phenotype

postnatal growth retardation
- incidence at 1-3 weeks; decreasing severity with age

decreased body size
- although mutants gain weight after weaning, they remain smaller as adults than wild-type

hearing/vestibular/ear phenotype

abnormal auditory brainstem response
- The ABR wave form is not observed in mutants, even at 99 db

abnormal membranous labyrinth morphology
- in the ampullae of the semicircular ducts, the membranous labyrinth is collapsed upon the cupula
- the membranous labyrinth in both the saccule and utricle is irregular and generally collapsed

abnormal strial marginal cell morphology
- marginal cells lack the numerous basal processes seen in wild-type and are separated from basal and intermediate cells by intercellular spaces that are wider than in wild-type

decreased cochlear outer hair cell number
- outer hair cells are identified only infrequently

decreased cochlear inner hair cell number
- inner hair cells are identified only infrequently

deafness

absent tunnel of Corti
- the tunnel of Corti is often absent in mutants

abnormal ear physiology

abnormal stria vascularis morphology
- the intercellular spaces between the marginal cell layer and deeper layers of the stria vascularis are wider than in wild-type

collapsed Reissner membrane

abnormal tectorial membrane morphology
- accumulation of calcified crystalline material at the tectorial membrane

abnormal scala media morphology
- the lumen of the cochlear duct is collapsed
- some mutants exhibit a wide scala media lumen

homeostasis/metabolism phenotype

decreased salivation

mortality/aging

postnatal lethality, incomplete penetrance
- incomplete penetrance; 30% dead by 3 weeks of age

nervous system phenotype

abnormal cranial ganglia morphology
- reduced numbers of neuronal cell bodies in the spiral ganglion

decreased cochlear outer hair cell number
- outer hair cells are identified only infrequently

decreased cochlear inner hair cell number
- inner hair cells are identified only infrequently

behavior/neurological phenotype

circling

spinning

absent pinna reflex

abnormal motor coordination/balance

head bobbing

head tilt
- head is tilted to one side or tilted upward and backward with the nose held high

cardiovascular system phenotype

remittent intestinal hemorrhage
- incomplete penetrance

decreased systemic arterial blood pressure

References

Flagella M; Clarke LL; Miller ML; Erway LC; Giannella RA; Andringa A; Gawenis LR; Kramer J; Duffy JJ; Doetschman T; Lorenz JN; Yamoah EN; Cardell EL; Shull GE. 1999. Mice lacking the basolateral Na-K-2Cl cotransporter have impaired epithelial chloride secretion and are profoundly deaf. J Biol Chem 274(38):26946-55PubMed: 10480906 MGI: J:57651

Additional - Slc12a2^tm1Ges related

Technical Support

CONTACT TECHNICAL SUPPORT

Genotyping Protocols
- Separated PCR:Slc12a2
- Separated MCA:Slc12a2MCA
- Genotyping resources and troubleshooting
Breeding Considerations

When maintaining a live colony, heterozygous mice may be bred to wildtype mice from the colony or to FVB/NJ inbred mice. Homozygous mice are runted and engage in circling behavior and rapid spinning. The donating investigator confirms that 30% of homozygotes die by 4 weeks of age.
- Additional Breeding and Husbandry Support
Citation
When using the FVB.Cg-Slc12a2^tm1Ges/Mmjax mouse strain in a publication, please cite the originating article(s) and include MMRRC stock #34262 in your Materials and Methods section.

Animal Health Reports

Facility Barrier Level Descriptions

Production of mice from cryopreserved embryos or sperm occurs in a maximum barrier room, G200

The Jackson Laboratory's Genotype Promise

The Jackson Laboratory has rigorous genetic quality control and mutant gene genotyping programs to ensure the genetic background of JAX® Mice strains as well as the genotypes of strains with identified molecular mutations. JAX® Mice strains are only made available to researchers after meeting our standards. However, the phenotype of each strain may not be fully characterized and/or captured in the strain data sheets. Therefore, we cannot guarantee a strain's phenotype will meet all expectations. To ensure that JAX® Mice will meet the needs of individual research projects or when requesting a strain that is new to your research, we suggest ordering and performing tests on a small number of mice to determine suitability for your particular project. We do not guarantee breeding performance and therefore suggest that investigators order more than one breeding pair to avoid delays in their research.

Terms Of Use

General Terms and Conditions

See MMRRC for Additional Conditions of Distribution

Questions about Terms of Use

Licensing Information

Phone: 207-288-6470

Email: TechTran@jax.org

Donating Investigator

Genetic overview

Research Applications

Detailed Description

Development

Control Suggestions

Approximate Controls

Additional Information

Selected References

Slc12a2tm1Ges

Allele Symbol: Slc12a2tm1Ges

Disease Terms

Research Areas By Phenotype

This mouse can be used to support research in many areas including:

Mammalian Phenotype Terms by Genotype

Genotype: Slc12a2tm1Ges/Slc12a2tm1GesNot Specified

adipose tissue phenotype

digestive/alimentary phenotype

endocrine/exocrine gland phenotype

growth/size/body region phenotype

hearing/vestibular/ear phenotype

homeostasis/metabolism phenotype

mortality/aging

nervous system phenotype

behavior/neurological phenotype

cardiovascular system phenotype

References

Additional - Slc12a2tm1Ges related

Genotyping Protocols

Breeding Considerations

Citation

Animal Health Reports

Production of mice from cryopreserved embryos or sperm occurs in a maximum barrier room, G200

The Jackson Laboratory's Genotype Promise

Terms Of Use

Licensing Information

Slc12a2^tm1Ges

Allele Symbol: Slc12a2^tm1Ges

Genotype: Slc12a2^tm1Ges/Slc12a2^tm1Ges
Not Specified

Additional - Slc12a2^tm1Ges related