Gene expression analysis in Tibialis anterior (TA) muscle upon titration of myonuclear numbers

Skeletal muscle myofibers accrue hundreds of nuclei during post-natal development via fusion with activated satellite cells (myoblasts), which is absolutely reliant on expression of the muscle fusogen myomaker (Mymk) in the myoblasts. Using an inducible genetic approach to render myoblasts non-fusogenic (by tamoxifen-inducible Pax7-CreER mediated recombination of the Mymk gene exclusively in satellite cells), we blocked myonuclear accrual at different time-points of post-natal development and thereby titrated the number of nuclei in resultant mutant myofibers. These Microarray assays were carried out on age day 28 (P28) using total RNA isolated from control and mutant muscle to determine changes in transcriptional profiles of these muscles to (a) assess effects of myonuclear titration, and (b) identify adaptive mechanisms elicited in mutant muscles in response to myonuclear deficiency.

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Cramer AAW, Prasad V, Eftestøl E, Song T, Hansson KA, Dugdale HF, Sadayappan S, Ochala J, Gundersen K, Millay DP