Background: The tetracycline-responsive system (Tet-ON/OFF) has proven to be a valuable tool for manipulating gene expression in an inducible, temporal, and tissue-specific manner. The purpose of this study was to create and characterize a new transgenic mouse strain utilizing the human skeletal muscle α-actin (HSA) promoter to drive skeletal muscle-specific expression of the reverse tetracycline transactivator (rtTA) gene which we have designated as the HSA-rtTA mouse.
Methods: To confirm the HSA-rtTA mouse was capable of driving skeletal muscle-specific expression, we crossed the HSA-rtTA mouse with the tetracycline-responsive histone H2B-green fluorescent protein (H2B-GFP) transgenic mouse in order to label myonuclei.
Results: Reverse transcription-PCR confirmed skeletal muscle-specific expression of rtTA mRNA, while single-fiber analysis showed highly effective GFP labeling of myonuclei in both fast- and slow-twitch skeletal muscles. Pax7 immunohistochemistry of skeletal muscle cross-sections revealed no appreciable GFP expression in satellite cells.
Conclusions: The HSA-rtTA transgenic mouse allows for robust, specific, and inducible gene expression across muscles of different fiber types. The HSA-rtTA mouse provides a powerful tool to manipulate gene expression in skeletal muscle.
Digital Object Identifier (DOI)
This work was supported by NIH grants AG049806 and AR060701 to JJM and CAP and AR071753 to KAM.
The datasets used and/or analyzed during the current study are available from the corresponding author on request. The HSA-rtTA mouse is available upon request.
Iwata, Masahiro; Englund, Davis A.; Wen, Yuan; Dungan, Cory M.; Murach, Kevin A.; Vechetti, Ivan J. Jr.; Mobley, Christopher B.; Peterson, Charlotte A.; and McCarthy, John J., "A Novel Tetracycline-Responsive Transgenic Mouse Strain for Skeletal Muscle-Specific Gene Expression" (2018). Center for Muscle Biology Faculty Publications. 7.