B6.Cg-Tg(S100A8-cre,-EGFP)1Ilw/J

Stock number: 021614
Product name: MRP8-Cre-ires/GFP
Strain synonyms: Mrp8cre^Tg
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

These MRP8-Cre-ires/GFP transgenic mice may be useful in studies utilizing "Cre-lox" technology or fluorescent protein expression in granulocytes and granulocyte/macrophage progenitors (GMPs).

Detailed description

MRP8-Cre-ires/GFP transgenic mice have the human S100 calcium binding protein A8 (calgranulin A) (MRP8 or S100A8) promoter directing bicistronic Cre and EGFP protein expression to granulocytes and granulocyte/macrophage progenitors (GMPs). EGFP fluorescence and cre expression is evident in hemizygotes in 20% of granulocyte/macrophage progenitors (GMPs) and 100% of granulocytes during myeloid differentiation. When bred with mice containing a loxP-flanked sequence of interest, the resulting offspring can have Cre-mediated recombination of the flanked sequence in these cells.

Mice hemizygous for the are viable and fertile, yet no homozygous mice are produced from hemizygous matings.



In February 2021, The Jackson Laboratory examined a cohort of MRP8-Cre-ires/GFP hemizygous mice peripheral blood for flow cytometry analysis of GFP and the CD11b Ly6G markers. This confirmed GFP expression in MRP8-Cre-ires/GFP peripheral blood CD11b+ Ly6G+ population [neutrophils; view data].



Recently, it was determined that a single copy of the MRP8-Cre-ires/GFP transgene integrated at a single site on chromosome 5 (137,042,580-137,086,690; mouse mm10). This insertion leads to a 44 kb deletion of the host genome, resulting in complete deletion of the serine (or cysteine) peptidase inhibitor, clade E, member 1 (Serpine1) gene and partial deletion of the adaptor protein complex AP-1, sigma 1 (Ap1s1) gene [Wang et al. 2022 Front. Immunol.]. The lethality seen in homozoygous mice is most likely due to prenatal lethality resulting from disrupted Ap1s1 gene expression.

Development

The MRP8-Cre-ires/GFP transgene was designed to place a Cre recombinase gene, internal ribosomal entry site (IRES), and an enhanced green fluorescent protein (EGFP) gene all downstream of the human S100 calcium binding protein A8 (calgranulin A) (MRP8 or S100A8) promoter. This transgene was microinjected into the pronucleus of (C57BL/6 x C3H)F1 fertilized oocytes. Resulting transgenic mice were bred to C57BL/6J mice for at least 9 generations. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J (Stock No. 000664) for at least one generation to establish the colony.

Recently, it was determined that a single copy of the MRP8-Cre-ires/GFP transgene integrated at a single site on chromosome 5 (137,042,580-137,086,690; mouse mm10). This insertion leads to a 44 kb deletion of the host genome, resulting in complete deletion of the serine (or cysteine) peptidase inhibitor, clade E, member 1 (Serpine1) gene and partial deletion of the adaptor protein complex AP-1, sigma 1 (Ap1s1) gene. [Wang et al. 2022 Front. Immunol.]

Allele

Symbol: Tg(S100A8-cre,-EGFP)1Ilw
Name: transgene insertion 1, Irving L Weissman
MGI accession ID: MGI:4415239
Generation method: Transgenic
Attributes: Recombinase-expressing
Synonyms: Mrp8cre^Tg; MRP8-Cre-ires/GFP; Tg(S100A8-cre,-GFP)1Empa; Tg(S100A8-cre,-GFP)1Ilw
Marker symbol: Tg(S100A8-cre,-EGFP)1Ilw
Marker name: transgene insertion 1, Irving L Weissman
Marker synonyms: Tg(S100A8-cre,-GFP)1Empa
Chromosome: 5
Strain of origin: (C57BL/6 x C3H)F1
Expressed genes: GFP,Green Fluorescent Protein,; cre,cre recombinase,bacteriophage P1
Site of expression: EGFP fluorescence and cre expression is evident in hemizygotes in 20% of granulocyte/macrophage progenitors and 100% of granulocytes during myeloid differentiation.
Molecular note: The human promoter drives expression of cre followed by an IRES sequence and EGFP in granulocytes and a fraction of myelomonocytic progenitors. Two founders were generated (no line information given). a A single copy of the transgene integrated at a single site on chromosome 5 (137,042,580-137,086,690; mouse mm10). This insertion leads to a 44 kb deletion of the host genome, resulting in complete deletion of the Serpine1 gene and partial deletion of the Ap1s1 gene.