B6.Cg-Tg(Gfap-cre)77.6Mvs/J

Stock number: 012887
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

In 2014, The Jackson Laboratory Stock No. 012887 was confirmed to have the same expression pattern as GFAP-Cre line 73.12 (Stock No. 012886). Therefore, Stock No. 012887 was discontinued. To replace it, The Jackson Laboratory is offering the correctly-expressing GFAP-Cre line 77.6 mice from Dr. Michael Sofroniew to establish a new GFAP-Cre line 77.6 colony as Stock No. 024098.

Detailed description

Mice hemizygous for the Gfap-cre transgene are viable and fertile, with a mouse glial fibrillary acidic protein (mGfap) promoter sequence directing expression of Cre recombinase. Specifically, Cre recombinase activity (as defined by expression of a floxed-STOP reporter gene) is targeted to most astrocytes throughout healthy brain and spinal cord tissues, and to essentially all astrocytes following central nervous system (CNS) injury.

These GFAP-Cre line 77.6 mice (Stock No. 012887) also have Cre recombinase activity in a subpopulation of adult neural stem cells in the subventricular zone. In contrast to GFAP-Cre line 73.12 (Stock No. 012886), GFAP-Cre line 77.6 mice are reported to have no Cre recombinase activity in postnatal or adult neural stem cells (or their progeny) from the hippocampus or other brain regions. As such, GFAP-Cre line 77.6 mice are particularly useful for selective targeting of astrocytes.

When these transgenic mice are bred with mice containing a loxP-flanked sequence, Cre-mediated recombination is expected to result in deletion of the floxed sequences in the Cre recombinase-expressing tissues of the offspring. These mice may be useful for studying astrocytes in the brain and spinal cord.

Development

The mGFAP-Cre transgene was designed with the entire mouse glial fibrillary acidic protein gene (Gfap) sequences directing expression of Cre recombinase. The construct has a small fragment of the Gfap first exon removed to prevent GFAP expression from the transgene. The transgene was microinjected into fertilized (BALB/c x C57BL/6NHsd)F1 oocytes. Transgenic founders were bred to C57BL/6 mice, and founder line 77.6 was identified. The GFAP-Cre line 77.6 colony was backcrossed to C57BL/6 animals (see SNP note below) for at least 14 generations, and then sent to The Jackson Laboratory Repository in 2010 as Stock No. 012887. Upon arrival, males were used to cryopreserve sperm. To establish the living mouse colony, an aliquot of the frozen sperm was used to fertilize oocytes from C57BL/6J inbred mice (Stock No. 000664).

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, 4 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 C57BL/6N genetic background.

Allele

Symbol: Tg(Gfap-cre)77.6Mvs
Name: transgene insertion 77.6, Michael V Sofroniew
MGI accession ID: MGI:3838840
Generation method: Transgenic
Attributes: Recombinase-expressing
Marker symbol: Tg(Gfap-cre)77.6Mvs
Marker name: transgene insertion 77.6, Michael V Sofroniew
Chromosome: UN
Strain of origin: (BALB/c x C57BL/6NHsd)F1
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: Cre recombinase activity is is observed in most astrocytes throughout the healthy brain and spinal cord and to essentially all astrocytes after Central Nervous System (CNS) injury. Cre recombinase activity is also observed in a subpopulation of the adult stems in the subventricular zone. In contrast to Tg(Gfap-cre)73.12Mvs, there is no targeting of postnatal or adult neural stem cells or their progeny in the hippocampus or other brain regions in Tg(Gfap-cre)77.6Mvs.
Molecular note: The bacterial Cre recombinase gene was inserted into the first exon of an expression cassette (clone 445) that contains all the introns, promoter regulatory elements, exons, and 2.5 kb of 5' and 2 kb of 3' flanking DNA of the astroglia-specific mouse glial fibrillary acidic protein gene. GFAP is not expressed from the transgene due to deletion of part of exon 1. Cre expression was detected in a small population of cells within the subependymal zone in the adult brain. No Cre expression or activity was detected during embryonic development or in the hippocampus.