B6.Cg-Tg(A930038C07Rik-cre)1Aibs/J

Stock number: 017346
Product name: A930038C07Rik-Tg1-Cre
Research areas: Neurobiology Research, Research Tools

Description

These A930038C07Rik-Tg1-Cre mice express Cre recombinase under the control of the A930038C07Rik (RIKEN cDNA A930038C07 gene [also called epidermacan]) promoter/enhancer regions within the BAC transgene. These mice may be useful for generating conditional mutations for studying gain or loss of function and/or fate mapping in subgroups of brain tissues; specifically in neocortical deep layer 5 (Layer 5B) cells/thick-tufted pyramidal neurons of adult mice.

Detailed description

Hemizygous A930038C07Rik-Tg1-Cre mice are viable and fertile, with Cre recombinase expression directed by the epidermacan (A930038C07Rik) promoter/enhancer regions within the BAC transgene. When A930038C07Rik-Tg1-Cre mice are bred with mice containing loxP-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the epidermacan-expressing cells of the double mutant offspring. Specifically, the donating investigator reports Cre recombinase activity/cre expression (via in situ hybridization to Cre recombinase) in adult mice as specific and unique to deep layer 5 (Layer 5B) cortical cells corresponding to thick-tufted pyramidal neurons. When crossing to a Cre-reporter line, reporter gene expression appears to be much more widespread (presumably due to more widespread cre expression during development). These other regions include scattered cells in main olfactory bulb, anterior olfactory nucleus, taenia tecta, piriform areas, lateral septal nuclei, and inferior olivary nucleus. The donating investigators may not have assessed expression in tissues other than brain. The phenotype of homozygous mice has not yet been characterized (October 2011).

Of note, these mice from founder line 1 (A930038C07Rik-Tg1-Cre; Stock No. 017346) have a much more specific expression pattern compared to mice from founder line 4 (A930038C07Rik-Tg4-Cre; see Stock No. 009616).

For characterization information of founder line 1, see images at the Allen Institute for Brain Science website (A930038C07Rik-Tg1-Cre images).

Development

The 196 kb C57BL/6J mouse bacterial artificial chromosome (BAC) RP23-476E22, containing the entire A930038C07Rik locus (and other genes), was modified by targeting a Cre recombinase coding sequence (the CreERT2 sequence modified back to encode the normal Cre recombinase gene), SV40 polyA signal, and frt-flanked neomycin cassette to the ATG start site of the A930038C07Rik locus. The targeted BAC sequences were further modified using FLP recombination to remove the selection cassette and linearized to remove its original vector backbone. The resulting modified BAC was microinjected into embryos from B6C3 mice ((C57BL/6 x C3H)F1 x C57BL/6). Mice from founder line A930038C07Rik-Tg1-Cre were bred to C57BL/6J mice to generate the colony. Mice were subsequently backcrossed to C57BL/6J mice for eight additional generation prior to sending to The Jackson Laboratory Repository. Upon arrival, A930038C07Rik-Tg1-Cre mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Tg(A930038C07Rik-cre)1Aibs
Name: transgene insertion 1, Allen Institute for Brain Science
MGI accession ID: MGI:5292251
Generation method: Transgenic
Attributes: Recombinase-expressing
Synonyms: A930038C07Rik-Tg1-Cre
Marker symbol: Tg(A930038C07Rik-cre)1Aibs
Marker name: transgene insertion 1, Allen Institute for Brain Science
Chromosome: UN
Strain of origin: (C57BL/6 x C3H)F1 x C57BL/6
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: Cre recombinase activity/cre expression (via in situ hybridization to Cre recombinase) in adult mice is observed as specific and unique to deep layer 5 (Layer 5B) cortical cells corresponding to thick-tufted pyramidal neurons. When crossing to a Cre-reporter line, reporter gene expression appears to be much more widespread (presumably due to more widespread cre expression during development). These other regions include scattered cells in main olfactory bulb, anterior olfactory nucleus, taenia tecta, piriform areas, lateral septal nuclei, and inferior olivary nucleus.
Molecular note: The 196 kb C57BL/6J mouse bacterial artificial chromosome (BAC) RP23-476E22, containing the entire A930038C07Rik locus (and other genes), was modified by targeting a Cre recombinase coding sequence, SV40 polyA signal, and frt-flanked neomycin cassette to the ATG start site of the A930038C07Rik locus. The targeted BAC sequences were further modified using FLP recombination to remove the selection cassette and linearized to remove its original vector backbone. The resulting modified BAC was microinjected into embryos from B6C3 mice ((C57BL/6 x C3H)F1 X C57BL/6). Mice from founder line A930038C07Rik-Tg1-Cre were bred to C57BL/6J mice to generate the colony. Detection of cre mRNA by in situ hybridization in adult mice is reported to be specific to layer 5 (Layer 5B) cortical cells corresponding to thick-tufted pyramidal neurons. Reporter activity in crosses to cre reporter mice is more widespread, presumably due to cre activity during development. This line demonstrates a much more specific expression pattern compared to mice from founder line 4 (Tg(A930038C07Rik-cre)1Aibs).