129S6.Cg-Tg(Gfap-TK)7.1Mvs/RhnJ

Stock number: 017523
Product name: Gfap-HSV-Tk , GFAP-TK
Research areas: Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools

Description

Expression of glial fibrillary acidic protein (Gfap) can be totally ablated from the jejunum and ileum in these transgenic mice by treatment with ganciclovir, making these mice useful in studies of inflammatory bowel disease and neurogenesis.

Detailed description

Mice hemizygous for the transgenic insert are viable, normal in size, and do not display any behavioral abnormalities. Transgenic males are infertile. Proliferating cells that express the herpes simplex virus thymidine kinase (HSV-TK) transgene will metabolize ganciclovir (GCV) to toxic nucleotide analogues and undergo cell death. Transgene-derived HSV-TK is present exclusively in cells expressing endogenous Gfap. This coexpression occurs in brain astrocytes and adult neural stem cells, enteric glia, hepatic stellate cells, and unknown cells in heart, lung, kidney, adrenal, and spleen. Chronic GCV treatment for 21 days depletes GFAP-positive adult neural stem cells from forebrain proliferative zones. GCV treatment eliminated growth of primary multipotent neurospheres cultured from the germinal zones of postnatal and adult, but not early embryonic, transgenic mice. Notably, the same treatment prevented growth of secondary multipotent neurospheres from all three developmental stages. Stab or spinal cord injury with high dose GCV treatment for 7 days induces reactive astroctye cell death leading to altered leukocyte trafficking and impaired injury healing. High dose GCV treatment for 14 days ablates GFAP-positive glia from the jejunum and ileum leading to fulminant and fatal jejuno-ileitis. This mutant can be used instudies of adult neurogenesis, nervous system injury/repair mechanisms, and inflammatory bowel disease.

Development

A herpes simplex virus thymidine kinase (HSV-TK) construct was inserted into the first exon of a mouse glial fibrillary acidic protein (GFAP) promoter cassette (clone 445). This cassette contains all the introns, promoter regulatory elements, exons, and 2.5 kb of 5' and 2 kb of 3' flanking regions of Gfap. Transgenic Gfap expression is prevented because a small segment of exon 1 has been removed in the clone. The Gfap-HSV-Tk fusion gene was injected into the male pronucleus of fertilized eggs from superovulated female C57BL/10 x CBA mated with CFLP outbred Swiss albino males. Two-cell stage eggs were implanted into pseudopregnant foster mothers. Founder line 7.1 was obtained and backcrossed to 129S6/SvEvTac mice by the donating investigator for more than 13 generations prior to sending females and males to The Jackson Laboratory Repository.

Allele

Symbol: Tg(Gfap-TK)7.1Mvs
Name: transgene insertion 7.1, Michael V Sofroniew
MGI accession ID: MGI:3664567
Generation method: Transgenic
Attributes: Inserted expressed sequence
Marker symbol: Tg(Gfap-TK)7.1Mvs
Marker name: transgene insertion 7.1, Michael V Sofroniew
Chromosome: UN
Strain of origin: (C57BL/10 x CBA)F1 X CFLP
Expressed genes: HSV-TK,herpes simplex virus thymidine kinase,
Molecular note: The Herpes simplex virus thymidine kinase gene, including the polyadenylation signal, was ligated into the first exon of a mouse glial fibrillary acidic protein promoter cassette that contains all the exons, introns and promoter regulatory elements and includes 2.5 kb of 5' and 2 kb of 3' flanking genomic DNA. The GFAP protein is not expressed from the transgene because a small segment of exon one has been deleted. RT-PCR analysis showed co-expression of HSV-Tk and of Gfap mRNA (from the endogenous gene) in heart, lung, liver, spleen, adrenal, kidney and GI tract, as well as in brain and trigeminal ganglion; in neural tissues the co-expressing cells have the appearance of astroglia.
General note: Line 7.1, estimated to carry >50 copies of the transgene, was selected from three original lines (the others unnamed) for further analysis because mice of this line exhibited the greatest HSV thymidine kinase expression in the brain.

Ganciclovir is metabolized to toxic nucleotide analogs in cells expressing HSV-TK. Subcutaneous or intraperitoneal administration of ganciclovir (GCV) or elaidic acid ganciclovir (eGCV) to transgenic mice results in specific ablation of proliferating cells that express GFAP.