Extended Data Figure 6. Selective and inducible knockdown of Slc1a5 in SC.

a, Schematic representation of the AAV8 expression vector for in vivo targeting of SC. U6, Pol III promoter driving the expression of the gRNA targeting the Slc1a5 locus or a non-targeting control gRNA. Since the mice used in this experiment are LSL-Cas9 x PAX7:Cre-ERT mice, Cas9 is exclusively activated in Pax7⁺ cells upon tamoxifen administration and, genome editing of the Slc1a5 locus will occur selectively in SC.

b, Schematic overview of an AAV8-based CRISPR/Cas9-mediated in vivo genome editing.

c-d, Representative images (c) and quantification (d) for Pax7 and Cas9 staining on uninjured muscles before and after tamoxifen administration (n=4).

e-f, RT-qPCR for Slc1a5 in freshly isolated SC (n=4) (e) and all other mononuclear cells (non-SC) (n=3) (f) upon in vivo genome editing of the Slc1a5 locus (SLC1A5-KD) specific in SC. Non-targeting control gRNA (Ctrl gRNA) was used as a control.

g-h, Quantification (g) and representative images (h) of SLC1A5 and Pax7 stainings on freshly isolated SC, upon in vivo genome editing of the Slc1a5 locus (SLC1A5-KD) specific in SC (n=3).

All experiments show representative values of at least 2 independent experiments. Unpaired two-tailed t-test was everywhere applied; ns, not significant (P>0.05). Scale bars: 50 μm (c); 20 μm (h). Graphs show mean ± SEM.