Fig. 1.

Expression of CXCL11 during myogenesis. a Western blot analysis demonstrated that CXCL11 levels gradually increase in C2C12 cells following the switch to differentiation conditions (DMEM + 1% FCS). a′ Relative levels of CXCL11 (mean ± SD, n = 3) as determined by densitometric analysis of immunoreactive protein bands in C2C12 cells maintained under differentiation conditions for the indicated times. CXCL11 levels present prior to the switch to differentiation conditions (day 0) were set to 1. *p < 0.05, **p < 0.005, respective time point vs. day 0. b CXCL11 expression is readily detectable by Western blot analysis in the rat quadriceps muscle at E18 with a clear decline into adulthood. b′ relative levels of CXCL11 (mean ± SD) as determined by densitometry of immunoreactive protein bands from 3 independent experiments. ***p < 0.001, respective time point vs. E18. Note in a and b that ß-actin as well as GAPDH, which are routinely used as loading controls for Western blotting, are developmentally regulated in muscle cells/fibres. Due to this fact, all samples were carefully adjusted to identical protein levels prior to analysis