B6;SJL-Tg(Slc26a4-rtTA2S*M2)1Ajg/J

Stock number: 028680
Product name: Tg[E]
Research areas: Cell Biology Research, Research Tools, Sensorineural Research

Description

Tg[E] mice are a Tet-On tool that allows conditional, doxycycline-inducible expression of the reverse tetracycline-controlled transactivator (rtTA) protein in inner ear epithelial cells.

Detailed description

Tg[E] BAC transgenic mice are viable and fertile, with a reverse tetracycline-regulated transactivator 2 (rtTA2) gene and a neo cassette, in reverse orientation, replacing the start codon of the solute carrier family 26, member 4 (Slc26a4 or Pendrin) gene on the BAC transgene. Pendrin is sodium-independent transporter of chloride and iodide expressed in inner ear, thyroid, kidney, and subset of other organs. Mutations in Pendrin have been associated with the onset of Pendred syndrome, a common form of syndromic autosomal-recessive deafness. Pendrin KO mice exhibit severe developmental abnormalities starting with enlargement of the endolymphatic sac and cochlea beginning at E14.5, cochlear endolymph acidification at E15.5, developmental retardation of the stria vascularis at P3, loss of the endocochlear potential at P10, degeneration of hair cells as early as P15, and failure to acquire hearing between P12 and P15. When mated to a second transgenic strain carrying a gene of interest under the regulatory control of a tetracycline-responsive promoter element (tetO), expression of the target gene 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. Hemizygous Tg[E] transgenic mice are viable and fertile.

When bred to a strain expressing Slc26a4 under control of the tetO promoter (Stock No. 028681), double transgenic mice on a Slc26a4-null background (Stock No. 018424) show differential effects on the severity of hearing loss by varying the temporal expression of Pendrin.

 

Development

The RP23-265L9 bacterial artificial chromosome (BAC) containing the solute carrier family 26, member 4 (Slc26a4 or Pendrin) gene was modified by replacing the Slc26a4 start codon in exon 2 with an rtTA2^S-M2 (reverse tetracycline-regulated transactivator) sequence and neomycin resistance gene in reverse orientation to the BAC. This modified 185.7 kb BAC transgene, still containing active Casitas B-lineage lymphoma-like 1 (Cbll1) and solute carrier family 26, member 3 Slc26a3 genes, was microinjected into fertilized (C57BL/6J × SJL) F2 oocytes, and mice from founder line 1 were bred to C57BL/6J mice to establish a colony of Tg[E] mice. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Tg(Slc26a4-rtTA2S*M2)1Ajg
Name: transgene insertion 1, Andrew J Griffith
MGI accession ID: MGI:5004919
Generation method: Transgenic
Attributes: Transactivator
Marker symbol: Tg(Slc26a4-rtTA2S*M2)1Ajg
Marker name: transgene insertion 1, Andrew J Griffith
Chromosome: UN
Strain of origin: (C57BL/6J x SJL)F2
Expressed genes: rtTA,reverse tetracycline-controlled transactivator,E. coli
Site of expression: Reverse tetracycline-regulated transactivator 2 is expressed in inner ear, thyroid, kidney, and subset of other organs.
Molecular note: This is a tet-on effector transgene with the rtTA-Neo cassette replacing the start codon of Slc26a4 in the mouse BAC RP23-265L9. The rtTA2S*M2 varient was used. The functionality of this transgene has been established in situ in combination with a responder transgene expressing Slc26a4 cDNA.