B6;SJL-Tg(Tagln-tTA)1Mrab Tg(tetO-Mcpt1)1Mrab/J

Stock number: 008082
Strain synonyms: SM22a-tTA/TRE-RVCH-HA
Research areas: Cardiovascular Research, Research Tools

Description

These SM22a-tTA/TRE-RVCH-HA bi-transgenic mice allow targeted overexpression or Tet-Off conditional expression of vascular chymase in smooth muscle cells, and may be useful in studying the role of elevated chymase activity in systemic hypertension and cardiovascular disease.

Detailed description

Hemizygous tTA+/RVCH+ (or SM22a-tTA/TRE-RVCH-HA) mice are viable and fertile, harboring two transgenes using the Tet-Off system. The SM22a-tTA transgene has the 3 kb SM22alpha promoter directing expression of the tetracycline transactivator gene (tTA) to vascular smooth muscle cells (SMCs). The TRE-RVCH-HA transgene has the tetracycline-responsive element (TRE; also called tet-operator or tetO) controlling expression of a rat vascular chymase-hemagglutinin tag (RVCH-HA) fusion gene. In the absence of tetracycline (or its analog doxycycline (dox)), the SM22alpha promoter limits RVCH-HA fusion protein expression to vascular SMCs. This RVCH overexpression results in hypertension. Because this binary transgenic system also allows for a second level of control, i.e. addition of dox, expression of the RVCH-HA fusion protein can be completely abolished; reversing the hypertension phenotype. These SM22a-tTA/TRE-RVCH-HA bi-transgenic mice allow targeted overexpression or Tet-Off conditional expression of vascular chymase in smooth muscle cells, and may be useful in studying the role of elevated chymase activity in systemic hypertension and cardiovascular disease.

Development

These mice harbor two transgenes using the Tet-Off system; SM22a-tTA and TRE-RVCH-HA. The SM22a-tTA transgene was designed with the 3 kb SM22alpha (transgelin or Tagln) promoter fragment upstream of the tetracycline transactivator gene (tTA). This construct was used to create transgenic mice on a C57BL/6 genetic background. The TRE-RVCH-HA transgene was designed with the tetracycline-responsive element (TRE; also called tet-operator or tetO) upstream of a rat vascular chymase (RVCH or Mcpt1) gene (modified such that a human influenza hemagglutinin (HA) tag is added to the C terminus of mature RVCH protein). This construct was used to create transgenic mice on an "SJL/B6" genetic background. These mice were next backcrossed to C57BL/6 mice for two to three generations and subsequently bred with the SM22a-tTA transgenic mice to generate bi-transgenic offspring (SM22a-tTA/TRE-RVCH-HA). These SM22a-tTA/TRE-RVCH-HA mice were maintained on a mixed SJL and C57BL/6 genetic background by breeding to wild-type siblings for at least 16 generations prior to arrival at The Jackson Laboratory. Upon arrival, these mice may have been bred with B6SJLF1/J (Stock No. 100012) hybrid mice to maintain the colony.

Allele

Symbol: Tg(tetO-Mcpt1)1Mrab
Name: transgene insertion 1, Marlene Rabinovitch
MGI accession ID: MGI:3772577
Generation method: Transgenic
Attributes: Inducible; Inserted expressed sequence
Synonyms: RVCH+; TRE-RVCH-HA
Marker symbol: Tg(tetO-Mcpt1)1Mrab
Marker name: transgene insertion 1, Marlene Rabinovitch
Chromosome: UN
Strain of origin: Not Specified
Expressed genes: Mcpt1,mast cell protease 1,rat
Site of expression: As the tetracycline-responsive element (TRE; also called tet-operator or tetO) controls expression of the rat vascular chymase-hemagglutinin tag (RVCH-HA) fusion gene, RVCH-HA expression is spatially and temporally dependent upon exposure to tetracycline transactivator (tTA).
Molecular note: The transgene was designed with the tetracycline-responsive element (TRE; also called tet-operator or tetO) upstream of a rat vascular chymase (RVCH or Mcpt1) gene modified such that a human influenza hemagglutinin (HA) tag is added to the C terminus of mature RVCH protein. With the addition of dox expression of the RVCH-HA fusion protein can be completely abolished, reversing the hypertension phenotype.

Allele

Symbol: Tg(Tagln-tTA)1Mrab
Name: transgene insertion 1, Marlene Rabinovitch
MGI accession ID: MGI:2447082
Generation method: Transgenic
Attributes: Transactivator
Synonyms: SM22alpha- tTA; tTA+
Marker symbol: Tg(Tagln-tTA)1Mrab
Marker name: transgene insertion 1, Marlene Rabinovitch
Chromosome: UN
Strain of origin: C57BL/6
Expressed genes: tTA,tetracycline-controlled transactivator,E. coli
Site of expression: vascular smooth muscle cells (SMCs)
Molecular note: Sequence encoding a tetracycline transactivator was adjoined to the smooth muscle cell specific transgelin promoter. The promoter was reported to drive expression in the aorta, but not in the heart, lung, kidney, bladder, intestine, or stomach.