Generation and characterization of a Tet-On (rtTA-M2) transgenic rat.
BACKGROUND
The tetracycline-inducible gene regulation system is a powerful tool that allows temporal and dose-dependent regulation of target transgene expression in vitro and in vivo. Several tetracycline-inducible transgenic mouse models have been described with ubiquitous or tissue-specific expression of tetracycline-transactivator (tTA), reverse tetracycline-transactivator (rtTA) or Tet repressor (TetR). Here we describe a Tet-On transgenic rat that ubiquitously expresses rtTA-M2 driven by the murine ROSA 26 promoter.


RESULTS
The homozygous rat line (ROSA-rtTA-M2) generated by lentiviral vector injection, has a single integration site and was derived from the offspring of a genetic mosaic founder with multiple transgene integrations. The rtTA-M2 transgene integrated into an intron of a putative gene on chromosome 2 and does not appear to affect the tissue-specificity or expression of that gene. Fibroblasts from the ROSA-rtTA-M2 rats were transduced with a TetO7/CMV-EGFP lentivirus and exhibited doxycycline dose-dependent expression of the EGFP reporter transgene, in vitro. In addition, doxycycline-inducible EGFP expression was observed, in vivo, when the TetO7/CMV-EGFP lentivirus was injected into testis, kidney and muscle tissues of ROSA-rtTA-M2 rats.


CONCLUSIONS
This conditional expression rat model may have application for transgenic overexpression or knockdown studies of gene function in development, disease and gene therapy.
Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
Yi
Y
Sheng
Chih-Cheng
CC
Lin
Junming
J
Yue
Meena
M
Sukhwani
Jennifer J
JJ
Shuttleworth
Tianjiao
T
Chu
Kyle E
KE
Orwig
D000818:Animals; D002460:Cell Line; D005347:Fibroblasts; D005821:Genetic Techniques; D051379:Mice; D011401:Promoter Regions, Genetic; D051381:Rats / Q000235:genetics*; D055647:Rats, Transgenic; D013752:Tetracycline; D015534:Trans-Activators / Q000235:genetics
D015534:Trans-Activators; D013752:Tetracycline