Fig. 4.

Loss of muscle spindles in Bicd2^−/− mice at 21 days of age. (a) shows example images of a cross section through a muscle spindle in Bicd2^+/+ and Bicd2^−/− mice stained for nuclei (DAPI, blue), the neuronal marker SV2/2H3 (green) and laminin (muscle membrane, red). Scale bars = 10 μm. The concentric SV2/SH3 staining around laminin positive muscle fibres indicates a muscle spindle (b) shows the total number of muscle spindles in the soleus muscle of Bicd2^+/+ and Bicd2^−/− mice, **p = 0.0065 (unpaired t-test, n = 4–5). (c) shows full innervation patterns in the muscle spindles of Bicd2^+/+ and Bicd2^−/− mice. Error bars = SEM. The loss of muscle spindles correlates with the loss of presumed gamma motor neurons in Bicd2^−/− compared to Bicd2^+/+ mice