Fig. 6.

MyD88 mediates myoblast fusion during skeletal muscle regeneration. a TA muscle of 12-week-old MyD88^f/f and MyD88^myoKO mice was injured by intramuscular injection of 100 µl of 1.2% BaCl₂ solution. After 5 days, the TA muscle was isolated and immunostained for eMyHC (green) and laminin (red) proteins. Nuclei were counterstained using DAPI (blue). Representative images are presented here. Arrows point to eMyHC⁻/laminin⁺ fibers. Scale bar: 50 µm. b Quantification of percentage of eMyHC⁺ myofibers within laminin staining, and c average CSA of eMyHC⁺ myofiber in TA muscle of MyD88^f/f and MyD88^myoKO mice. N = 3 in each group. *p < 0.05 from MyD88^f/f mice by unpaired t-test. In another experiment, TA muscle of MyD88^f/f and MyD88^myoKO mice was injured by intramuscular injection of 100 µl of 1.2% BaCl₂ solution. After 2 days, the mice were given an intraperitoneal injection of EdU and 11 days later TA muscles were collected and muscle sections prepared were stained to detect EdU, laminin, and nuclei. d Representative photomicrographs after EdU, laminin, and DAPI staining are presented here. Scale bar: 50 µm. e Quantification of the percentage of EdU⁺ nuclei per muscle fiber. N = 5 in each group. Error bars represent s.d. *p < 0.01 from MyD88^f/f mice by unpaired t-test