B6;129-Gabra1^tm4Geh/J

Stock number: 010948
Research areas: Neurobiology Research

Description

This targeted mutation of gamma-aminobutyric acid (GABA) A receptor, subunit alpha 1 (Gabra1), gene displays hyperactivity and may be useful in the study of alcohol and general anesthetic action in the nervous system.

Detailed description

Mice that are homozygous for the targeted mutation are viable, fertile and normal in size. In contrast to the single S270H knockin, which exhibits increased GABA sensitivity and multiple behavioral and neurological phenotypes, the double S270H L277A mutation restores GABA sensitivity.

Western blot analysis indicates an increase in the amount of GABAR subunits alpha3, beta2 , gamma3 and a decrease in alpha1 and beta3. Homozygous mice exhibit an increase in motor activity, but no other overt phenotype. Mutant mice show alterations in some, but not all, behavioral responses to alcohol and general anesthetics.

Development

The targeting vector was designed (by site-directed mutagenesis) to substitute a serine to histidine at amino acid position 270 and leucine to alanine at amino acid position 277 of exon 9. An FRT-flanked neomycin cassette was inserted upstream of exon 9. The construct was electroporated into 129X1/SvJ-derived Go Germline (Genome Systems) embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were crossed to C57BL/6J and the F1 progeny crossed to B6.Cg-Tg(ACTFLPe)9205Dym/J (actin-FLPe) to remove the neo cassette and leave a single FRT site upstream of exon 9. The transgene subsequently was bred out. Heterozygotes were intercrossed to maintain the colony. Upon arrival, mice were bred to C57BL/6J for at least 1 generation to establish the colony.

Allele

Symbol: Gabra1^tm4Geh
Name: targeted mutation 4, Gregg E Homanics
MGI accession ID: MGI:4361392
Generation method: Targeted
Marker symbol: Gabra1
Marker name: gamma-aminobutyric acid (GABA) A receptor, subunit alpha 1
Chromosome: 11
Strain of origin: 129X1/SvJ
Molecular note: The targeting vector was designed (by site-directed mutagenesis) to substitute a serine to histidine at amino acid position 270 and leucine to alanine at amino acid position 277 of exon 9. An FRT-flanked neomycin cassette was inserted upstream of exon 9. Chimeric animals were crossed to C57BL/6J and the F1 progeny crossed to B6.Cg-Tg(ACTFLPe)9205Dym/J (actin-FLPe) to remove the neo cassette and leave a single FRT site upstream of exon 9.