Fig. 1.

Ectopic accumulation of phosphorylated NFs does not occur in affected tissues of SMAΔ7 mice. Lumbar (a) spinal cord sections were immunostained with an antibody that recognizes dephosphorylated NFs (SMI-32) to identify motor neuron cell bodies. Ectopically phosphorylated NFs were identified with an antibody that recognizes NFs in a phosphorylated-dependent manner (SMI-31). NF localization was analyzed at both P11 and P16. Accumulation of ectopically phosphorylated NFs (red) was not observed in lumbar (a) motor neuron cell bodies, marked by nuclear DAPI staining (blue), at either time point. Scale bar 50 μm. NF phosphorylation and expression was not altered in SMAΔ7 (S) (N = 3) when compared with wild type (w) (N = 3) animals (b) shown by ROD analysis (c). Spinal cord lysates were separated on a 7.5% SDS polyacrylamide gels from wild type and SMAΔ7 mice at three different disease stages. Lysates were immunoblotted with antibodies recognizing phosphorylated NFs (SMI-31), unphosphorylated NFs (SMI-32) and a NF-L control (DA2). Statistical significance was determined by a Student’s t test