Figure 4. Prmt5 KO diminishes LD abundance and oxidative respiration of SCs, disrupting their cell fate homeostasis.

(A) Oil red O staining (left) and quantification (right) of LD content in control (MeOH) and Prmt5 KO (4-OH) myoblasts. Scale bar, 50 μm.

(B) Pax7 and Bodipy immunofluorescence (left) and quantification of Bodipy intensity (right) in control (MeOH) and Prmt5 KO (4-OH) myoblasts. Scale bar, 10 mm.

(C) Pax7 and Bodipy immunofluorescence (left) and quantification of Bodipy intensity (right) in SCs after proliferating for 72 h on cultured single myofibers isolated from WT and Prmt5^MKO mice. Scale bar, 10 μm.

(D) qPCR analysis of lipogenic marker (Pnpla2) and adipogenesis markers (Dgat1, Fabp4) in control (MeOH) and Prmt5 KO (4-OH) myoblasts (n = 4).

(E–G) Pax7 and MyoD fluorescence to distinguish cell fate status in WT and Prmt5^MKO SCs (E), quantification of SCs per cluster (F), and proportions of self-renewing (Pax7⁺MyoD⁻), proliferating (Pax7⁺MyoD⁺), and differentiating (Pax7⁻MyoD⁺) cells (G) after culturing on single myofibers for 72 h (n = 3). Scale bar, 10 μm.

(H) Seahorse measurement of oxygen consumption rate (OCR) in control (MeOH) and Prmt5 KO (4-OH) myoblasts in response to sequential addition of oligomycin, carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP), and rotenone/antimycin A (n = 3).

(I) Average OCR for basal respiration (BR), proton leak (PL), ATP respiration (ATP R), maximal respiration (Max R), spare capacity, and non-mitochondrial respiration (NR) based on H (n = 3). SC, spare capacity.

Values are expressed as mean ± SEM. *p < 0.05, **p < 0.01, ****p < 0.0001 by t test. See also Figure S4.