Figure 7. Exogenously expressed SUN1 mutants impair pericentrin recruitment to the nuclear envelope.

(A) Differentiated C2C12 myotubes transfected with wild-type (WT) SUN1, or the indicated mutants, were labelled with anti-myc (red) and anti-pericentrin antibodies (green). Desmin antibody (violet) was used as a muscle differentiation marker. Nuclei were counterstained using DAPI. Samples were observed using a Nikon laser confocal microscope. Bar, 10 µm. (B–C) Transfected myotubes prepared as in A were quantified for the absence of pericentrin staining at the nuclear envelope (B) and myonuclear clustering (C). Thirty myotubes per sample were counted in two independent experiments. Differences for all mutants were statistically significant with respect to wild-type-transfected myotubes (P<0.01).