Tetracycline-controlled transgene activation using the ROSA26-iM2-GFP knock-in mouse strain permits GFP monitoring of DOX-regulated transgene-expression.
BACKGROUND
Conditional gene activation is an efficient strategy for studying gene function in genetically modified animals. Among the presently available gene switches, the tetracycline-regulated system has attracted considerable interest because of its unique potential for reversible and adjustable gene regulation.


RESULTS
To investigate whether the ubiquitously expressed Gt(ROSA)26Sor locus enables uniform DOX-controlled gene expression, we inserted the improved tetracycline-regulated transcription activator iM2 together with an iM2 dependent GFP gene into the Gt(ROSA)26Sor locus, using gene targeting to generate ROSA26-iM2-GFP (R26t1Δ) mice. Despite the presence of ROSA26 promoter driven iM2, R26t1Δ mice showed very sparse DOX-activated expression of different iM2-responsive reporter genes in the brain, mosaic expression in peripheral tissues and more prominent expression in erythroid, myeloid and lymphoid lineages, in hematopoietic stem and progenitor cells and in olfactory neurons.


CONCLUSIONS
The finding that gene regulation by the DOX-activated transcriptional factor iM2 in the Gt(ROSA)26Sor locus has its limitations is of importance for future experimental strategies involving transgene activation from the endogenous ROSA26 promoter. Furthermore, our ROSA26-iM2 knock-in mouse model (R26t1Δ) represents a useful tool for implementing gene function in vivo especially under circumstances requiring the side-by-side comparison of gene manipulated and wild type cells. Since the ROSA26-iM2 mouse allows mosaic gene activation in peripheral tissues and haematopoietic cells, this model will be very useful for uncovering previously unknown or unsuspected phenotypes.
Wörtge
Simone
S
Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany.
Eshkind
Leonid
L
Cabezas-Wallscheid
Nina
N
Lakaye
Bernard
B
Kim
Jinhyun
J
Heck
Rosario
R
Abassi
Yasmin
Y
Diken
Mustafa
M
Sprengel
Rolf
R
Bockamp
Ernesto
E
D000818:Animals; D004318:Doxycycline; D055879:Gene Knock-In Techniques / Q000379:methods*; D005821:Genetic Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D013752:Tetracycline; D019076:Transgenes
D049452:Green Fluorescent Proteins; D013752:Tetracycline; D004318:Doxycycline
Genesis. 2008 Apr;46(4):193-9
18395834
Proc Natl Acad Sci U S A. 1984 Jun;81(12):3655-9
6587381
Handb Exp Pharmacol. 2007;(178):49-72
17203651
J Neurosci Methods. 2009 Jan 15;176(1):16-23
18801387
Nucleic Acids Res. 1995 Dec 25;23(24):5080-1
8559668
PLoS One. 2007 Jun 20;2(6):e533
17579707
Proc Natl Acad Sci U S A. 1997 Apr 15;94(8):3789-94
9108056
Genes Dev. 2003 Feb 15;17(4):488-501
12600942
FEBS Lett. 2002 Jun 5;520(1-3):47-52
12044868
Nat Genet. 1999 Jan;21(1):70-1
9916792
Physiol Genomics. 2002 Dec 3;11(3):115-32
12464688
Nucleic Acids Res. 2003 Feb 15;31(4):e12
12582257
Brain Res Mol Brain Res. 2001 Oct 19;94(1-2):96-104
11597769
Nucleic Acids Res. 2005 Sep 07;33(16):e137
16147984
Curr Opin Biotechnol. 1998 Oct;9(5):451-6
9821271
Eur J Immunol. 2007 Jan;37(1):43-53
17171761
Nucleic Acids Res. 2001 Apr 1;29(7):E39
11266574
Genesis. 2009 Jan;47(1):7-13
18942097
Science. 2000 Sep 15;289(5486):1942-6
10988076
J Virol. 1996 Jul;70(7):4646-54
8676491
BMC Dev Biol. 2007 Sep 27;7:108
17900353
J Neurosci. 2004 Nov 17;24(46):10568-78
15548671
Cell. 2005 May 6;121(3):465-77
15882627
Proc Natl Acad Sci U S A. 1993 Sep 15;90(18):8424-8
8378314
Mol Cell Biol. 1986 Jul;6(7):2593-601
3023940
Regen Med. 2008 Mar;3(2):217-35
18307405
Blood. 2006 Sep 1;108(5):1533-41
16675709
Science. 2001 Jun 29;292(5526):2501-4
11431570
Physiol Genomics. 2007 Sep 19;31(1):32-41
17456738
Nucleic Acids Res. 1996 Nov 15;24(22):4594-6
8948655
Annu Rev Biomed Eng. 2002;4:235-60
12117758
Nature. 1986 Aug 7-13;322(6079):562-5
3736674
Genes Dev. 1991 Sep;5(9):1513-23
1653172
BMC Dev Biol. 2001;1:4
11299042
Proc Natl Acad Sci U S A. 2000 Jul 5;97(14):7963-8
10859354
Science. 1996 Dec 6;274(5293):1678-83
8939850
J Gene Med. 1999 Jan-Feb;1(1):4-12
10738580
Blood. 2001 Jan 1;97(1):324-6
11133778
PLoS One. 2006 Dec 20;1:e4
17183668
J Neurosci. 1999 Mar 15;19(6):2037-50
10066257
Genesis. 2008 Apr;46(4):200-4
18395835