B6.Cg-Tg(Gad1-EGFP)3Gfng/J

Stock number: 007673
Research areas: Neurobiology Research, Research Tools

Description

These GAD67-GFP (line 3) mice may be useful for fluorescent labeling of neurons and studying the development, maturation, regulation, and functional integration of newborn neurons in adult hippocampus.

Detailed description

Mice hemizygous for this GAD67-GFP transgene are viable and fertile. In the hippocampus, GAD67-GFP (line 3) mice selectively express enhanced green fluorescent protein (EGFP) in newborn dentate granule cells. At two weeks of age, EGFP is expressed in large numbers of dentate granule cells, and the number of EGFP-positive cells diminishes with age in a pattern consistent with the postnatal development of dentate granule cells/age-related reduction in adult neurogenesis in the dentate gyrus. The EGFP expression in newborn dentate granule cells begins within the first week of cell division and disappears as newborn neurons mature (about 4 weeks postmitotic), and EGFP positive dentate granule cells also express the newborn neuron markers PSA-NCAM and doublecortin. The bright labeling of newborn neurons with EGFP makes it possible to visualize the details of dendrites, which reach the outer edge of the molecular layer, and their axon terminals (mossy fiber boutons) in the CA3 region. In addition, EGFP is expressed in GABAergic neurons in many regions of the brain including the Purkinje cells of the cerebellum, periglomerular neurons of the olfactory bulb, and interneurons of the superior colliculus and brainstem. In some regions of the brain (thalamus, hypothalamus, cortex and striatum) sparse EGFP labeling is seen, with all EGFP positive cells also GAD67 positive in these regions. EGFP expression is not reported in hippocampal interneurons, including those in the hilus. Because the transgene contains loxP sites surrounding the GAD67-GFP sequences, crossing to a cre expressing strain will result in offspring bearing a deletion of the GAD67-GFP transgene. These GAD67-GFP (line 3) mice may be useful for fluorescent labeling of neurons and studying the development, maturation, regulation, and functional integration of newborn neurons in adult hippocampus.

Of note, this GAD67-GFP strain is one of many fluorescent GABAergic neuron strains, each with unique labeling characteristics (see Stock No. 003718, Stock No. 006334, Stock No. 006340, and Stock No. 007677).

Development

The bacterial artificial chromosome (BAC) clone RP23-118N13 containing the mouse GAD67 gene (and 120 kb of upstream and 46 kb downstream sequence) was modified by insertion of an Enhanced Green Fluorescent Protein (EGFP) cDNA and polyadenylation sequence at the translation initiation site of the GAD67 gene. This GAD67-GFP BAC, flanked by loxP sites as a result of insertion into the vector, was microinjected into fertilized (C57BL/6J x SJL)F1 oocytes. Transgenic offspring were bred to C57BL/6J mice. The donating investigator reported that founders with appropriate GFP expression levels and patterns (founder line 3) were established and bred to C57BL/6 for at least six generations (see SNP note below) prior to arrival at The Jackson Laboratory.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, at least 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Tg(Gad1-EGFP)3Gfng
Name: transgene insertion 3, Guoping Feng
MGI accession ID: MGI:3721803
Generation method: Transgenic
Attributes: Reporter
Marker symbol: Tg(Gad1-EGFP)3Gfng
Marker name: transgene insertion 3, Guoping Feng
Chromosome: UN
Strain of origin: (C57BL/6J x SJL)F1
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: In newborn dentate granule cells in the hippocampus during development and in the adult.
Molecular note: The bacterial artificial chromosome (BAC) clone RP23-118N13 containing the mouse GAD67 gene (and 120 kb of upstream and 46 kb downstream sequence) was modified by insertion of an Enhanced Green Fluorescent Protein (EGFP) cDNA and polyadenylation sequence at the translation initiation site of the GAD67 gene. This GAD67-GFP BAC was microinjected into fertilized (C57BL/6J x SJL)F1 oocytes. Founder line 3 was established. Selective transgene expression is observed in newborn dentate granule cells of the adult hippocampus (subgranular zone of the dentate gyrus). EGFP is strongly expressed in the Purkinje cells of the cerebellum, periglomerular neurons of the olfactory bulb, and interneurons of the superior colliculus and brainstem with fluorescence observed in neurons (including axon terminals, dendrites and dendritic spines). Sparse EGFP labeling is reported in the thalamus, hypothalamus, cortex and striatum.