B6;129S6-Gt(ROSA)26Sor^{tm1(rtTA2S*M2)Whsu}/J

Stock number: 016999
Research areas: Neurobiology Research, Research Tools

Description

This R26STOPrtTA mutant mouse strain combines two popular conditionally-regulated expression methodologies (Tet Expression and Cre Recombinase) providing a tool for doxycycline-inducible spatiotemporal and lineage specific expression of genes.

Detailed description

These mice contain the rtTAS*M2, or rtTA2^S-M2, an optimized form of reverse tetracycline regulated transactivator, gene inserted into the Gt(ROSA)26Sor locus. Expression of the rtTAS*M2 is blocked by a loxP-flanked STOP fragment placed between the rtTAS*M2 sequence and the Gt(ROSA)26Sor promoter. When these mutant mice are bred to mice that express Cre recombinase, the resulting offspring will express rtTAS*M2, reverse tetracycline regulated transactivator, in the cre expressing cells. When bred to mice that also carry a gene of interest under the regulatory control of a tetracycline-responsive promoter element (tetO), expression of the gene of interest may be regulated by the tetracycline analog, doxycycline (dox). In the presence of dox, transcription of the target gene is induced in cells where rtTA is expressed. Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities.

Development

A targeting vector was used to insert a loxP flanked STOP sequence followed by an optimized reverse tetracycline-controlled transactivator, rtTAS*M2, or rtTA2^S-M2, into Gt(ROSA)26Sor. The construct was electroporated into 129S6/SvEvTac derived CSL3 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. The resulting chimeric animals were crossed to C57BL/6J mice for an unknown number of generations. Homozygote males were then crossed to wildtype 129S6/SvEvTac females. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

Allele

Symbol: Gt(ROSA)26Sor^{tm1(rtTA2S*M2)Whsu}
Name: targeted mutation 1, Wei Hsu
MGI accession ID: MGI:3584142
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Transactivator
Marker symbol: Gt(ROSA)26Sor
Marker name: gene trap ROSA 26, Philippe Soriano
Chromosome: 6
Strain of origin: 129S6/SvEvTac
Site of expression: When mice carrying this allele are bred to mice that express Cre recombinase, the resulting offspring will express rtTAS*M2, reverse tetracycline regulated transactivator, in the cre expressing cells. When bred to mice that also carry a gene of interest under the regulatory control of a tetracycline-responsive promoter element (tetO), expression of the gene of interest may be regulated by the tetracycline analog, doxycycline (dox). In the presence of dox, transcription of the target gene is induced in cells where rtTA is expressed.
Molecular note: A synthetic modified version of the rtTA gene preceded by a loxP flanked STOP sequence was inserted into the Gt(ROSA)26Sor locus. This version of rtTA contains 5 amino acid changes in the TetR moiety (S12G, E19G, A56P, D148E, and H179R) and a synthetic optimized transactivating domain. This rtTA has reduced basal activity and enhanced doxycycline sensitivity compared to wild-type rtTA.