Figure 1. Skeletal muscle atrophy and apoptosis in SMA mice.

H&E staining was performed on transverse sections of the lower hindlimb at P5 (A), and whole body at P4 (B – lumbar spinal cord and back muscles, C – masseter, D – forelimb muscles, E – lumbar back muscles). Representative skeletal muscle images from control (left column) and SMA mice (right column) are shown at the same scale. Arrows and insets indicate apoptotic profiles (condensed, fragmented nuclei). Dotted lines in A delineate areas quantified. Some muscle groups were not quantified in their entirety because they were not intact or were not identifiable on all sections. TA – tibialis anterior muscle, Fdl/Edl – flexor/extensor digitorum longus muscle, Sol – soleus muscle, LG – gastrocnemius lateralis muscle, MG – gastrocnemius medialis muscle.