STOCK Tg(Pax4-cre)1Dam/J

Stock number: 014158
Research areas: Endocrine Deficiency Research, Research Tools

Description

Pax4-cre transgenic mice have the mouse paired box gene 4 (Pax4) promoter directing expression of an enhanced green fluorescent protein fused to a Tet-off cassette (EGFP/tTA). The transgene also contains a tetracycline-responsive element with a CMV minimal promoter (tetO-CMVmin) driving expression of a Cre-recombinase. The Pax4 promoter drives expression of Cre in pancreatic progenitor cells. The donating investigator confirms the absence of GFP expression, tTA activity, and tetracycline-dependant inhibition of Cre recombinase in this transgenic strain. While not useful as a Tet-Off tool, these mice may be useful as for studying pancreatic islet development and beta cell differentiation.

Detailed description

Pax4-cre transgenic mice have the mouse paired box gene 4 (Pax4) promoter directing expression of an enhanced green fluorescent protein fused to a Tet-off cassette (EGFP/tTA). The transgene also contains a tetracycline-responsive element with a CMV minimal promoter (tetO-CMVmin) driving expression of a Cre-recombinase gene. In the absence of tetracycline/doxycycline, Cre recombinase expression is observed in Pax4-expressing cells (pancreatic progenitor cells). While designed to concomitantly allow tetracycline/doxycycline-dependant inhibition of Cre recombinase expression, the donating investigator confirms no such inhibition is observed. Also, no GFP expression is observed with or without tetracycline/doxycycline administration. Therefore, Pax4-cre transgenic mice function only for Cre recombinase expression in Pax4-expressing cells. When bred with mice containing a loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in the Pax4-expressing cells of the offspring. While not useful as a Tet-Off tool, these mice may be useful as for studying pancreatic islet development and beta cell differentiation.

For example, when bred to STOCK Gt(ROSA)26Sor^{tm1(Notch1)Dam}/J mice (Stock No. 008159), Notch activation inhibits the differentiation of pancreatic progenitor cells into α and β endocrine cells and shunts them instead toward a duct fate.

Development

The Pax4-cre transgene was designed with the mouse paired box gene 4 (Pax4) promoter directing expression of an enhanced green fluorescent protein fused to a Tet-off cassette (EGFP/tTA). The transgene also contained a tetracycline-responsive element with a CMV minimal promoter (tetO-CMVmin) driving expression of a Cre-recombinase. Of note, these Pax4-cre transgenic mice function only for Cre recombinase expression in Pax4-expressing cells (no Tet-Off or fluorescent function is reported: see strain phenotype description for more details). The transgene was microinjected into fertilized (C57BL/6 X CBA) F1 oocytes, and founder mice were bred to ICR outbred mice to establish a colony. Upon arrival at The Jackson Laboratory, transgenic mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Tg(Pax4-cre)1Dam
Name: transgene insertion 1, Douglas A Melton
MGI accession ID: MGI:4868408
Generation method: Transgenic
Attributes: Recombinase-expressing
Marker symbol: Tg(Pax4-cre)1Dam
Marker name: transgene insertion 1, Douglas A Melton
Chromosome: UN
Strain of origin: (C57BL/6 x CBA)F1
Expressed genes: cre,cre recombinase,bacteriophage P1
Molecular note: The Pax4-cre transgene was designed with the mouse paired box gene 4 (Pax4) promoter directing expression of an enhanced green fluorescent protein fused to a tet-off cassette (EGFP/tTA). The transgene also contained a tetracycline-responsive element witha CMV minimal promoter (tetO-CMVmin) driving expression of a cre-recombinase.
General note: These Pax4-cre transgenic mice function only for cre recombinase expression in Pax4-expressing cells (no tet-Off or fluorescence function is reported). The transgene was microinjected into fertilized (C57BL/6 X CBA)F1 oocytes, and founder mice were bred to ICR outbred mice to establish a colony.