STOCK Tg(tetO-SMN2,-luc)#bAhmb/J

Stock number: 017600
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

These Luci-TRE-SMN transgenic mice harbor the "new" pBI-L-SMN(B) transgene designed to express both luciferase and a full-length human SMN gene under the control of a bi-directional tet-responsive promoter. These "new" Luci-TRE-SMN(B) mice allow high levels of both luciferase and full-length human SMN expression to be regulated by the addition/removal of dox, and offer a means to generate mutant mice for Tet-Off/Tet-On and/or fluorescent protein studies of Spinal Muscular Atrophy (SMA).

Detailed description

Mice hemizygous for the "new" pBI-L-SMN(B) transgene ("new" Luci-TRE-SMN(B) transgene mice) are viable and fertile, with no reported phenotypic abnormalities. These Luci-TRE-SMN transgenic mice express luciferase and a full-length (exons 1-8) human SMN gene under the control of a bi-directional tet-responsive promoter (TRE or tetO). When bred with another mouse expressing tetracycline-controlled transactivator protein (tTA) or reverse tetracycline-controlled transactivator protein (rtTA), simultaneous luciferase and SMN expression can be regulated with the tetracycline analog doxycycline (dox) in the resulting double mutant offspring. These Luci-TRE-SMN transgenic mice are useful to generate mutant mice for Tet-Off/Tet-On and/or fluorescent protein studies of Spinal Muscular Atrophy.

Development

The Luci-TRE-SMN transgene was created by Dr. Arthur HM Burghes (The Ohio State University). The Luci-TRE-SMN transgenic construct used here ["new" pBI-L-SMN(B)] was designed with a luciferase sequence on one side, and a full-length human SMN2 cDNA sequence (encoding exons 1-8) on the other side of the P_bi-1 bi-directional tetracycline-responsive promoter. The 1.37 kb human SMN2 cDNA sequence was derived via RT-PCR performed on total RNA isolated from SMA type 1-derived patient fibroblast cells (Coriell Institute GM 3813; shown to express both full-length and truncated SMN2 transcripts). Compared to the "old" pBI-L-SMN construct, the "new" pBI-L-SMN(B) construct used here has a 31 bp sequence (including a hemagglutinin epitope tag sequence) deleted between the P_bi-1 promoter and 5' end of SMN2 cDNA, as well as additional SMN2 exon 8 UTR sequence downstream of the SMN2 cDNA. The P_bi-1 promoter contains the Tet-responsive element (TRE; seven copies of the 42-bp tet operator sequence [tetO]) placed between two minimal CMV enhancer-less promoters. The "new" Luci-TRE-SMN(B) transgene was microinjected into the male pronucleus of FVB/N embryos. Founder mice were bred with Camk2a-tTA mice (FVB background; see Stock No. 003010) to determine which lines had high dox-inducible levels of luciferase and SMN in brain. The high-expressing "new" Luci-TRE-SMN(B) founder line was identified and used to create the Tg(SMN2)89; Smn1^+/-; Tg(SMNΔ7)4299; ROSA26^rtTA; "new" Luci-TRE-SMN(B) mice (on a mixed FVB/N and C57BL/6 genetic background) that was sent to The Jackson Laboratory Repository as Stock No. 017597). Upon arrival, some mice were bred with FVB/NJ inbred mice (Stock No. 001800) for several generations to remove the other transgenes/mutations. The resulting mice harboring only the "new" Luci-TRE-SMN(B) transgene were assigned Stock No. 017600.

Allele

Symbol: Tg(tetO-SMN2,-luc)#bAhmb
Name: transgene insertion, Arthur H M Burghes
MGI accession ID: MGI:5318802
Generation method: Transgenic
Attributes: Reporter; Inducible; Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(tetO-SMN2,-luc)#bAhmb
Marker name: transgene insertion, Arthur H M Burghes
Chromosome: UN
Strain of origin: FVB/N
Expressed genes: SMN2,survival of motor neuron 2, centromeric,human; luc,luciferase,firefly
Site of expression: When bred to mice expressing a tetracycline transactivator (tTA) or reverse transactivator (rtTA), doxycycline induction results in the expression of luciferase and SMN expression in transactivator expressing tissues of the offspring.
Molecular note: The tetracycline response element with two minimal CMV promoters drives inducible expression of human SMN (exons 1 through 8) and a luciferase gene.