Distribution of TDP-43 and phosphorylated TDP-43 (pTDP-43) aggregates in TDP-43
mice. Immunostaining in spinal cord sections of a 1-month old TDP-43M337V from (A) line 4, (B) line 6 and (C) NT mice shows hTDP-43 in nuclei, with occasional cytoplasmic staining (arrowhead); hTDP-43 was not observed in NT mice. (D-F) Immunostaining of spinal cord sections for total TDP-43 shows that TDP-43 immunoreactivity in both nuclei and cytoplasm in TDP-43M337V mice (arrowhead) (D-E), but only in nuclei in NT mice (F). Immunostaining of spinal cord (G-I) or cortical (J-L) neurons for phosphorylated (p403/404) TDP-43. (G-H) Nuclear bodies (arrowheads) within spinal motor neurons of TDP-43M337V mice immunostained for pTDP-43. Occasionally, diffuse cytoplasmic pTDP-43 was found within the motor neurons in the anterior horn of TDP-43M337V mice (arrows). (I) NT mice lacked similar pTDP-43 staining in the spinal cord. (J-K) Cytoplasmic aggregates of pTDP-43 (arrows) were often seen in cortical neurons of TDP-43M337V mice that were absent from (L) NT mice. Scale bars: 50 μM.