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Fig. 1. HuD protein colocalizes with tau mRNA in RNP granules. (A) Confocal image
analysis of HuD protein localization in differentiated P19 cells. (a) Phase
image of a differentiated P19 cell. (b) Expression of GFP-tau protein. (c)
Staining with HuD antibodies. (d) In situ hybridization analysis with the GFP
probe (which detects the transfected tau mRNA). (e) Merged confocal image of
b, c and d (x2500 magnification). The solid arrowheads denote axons;
empty arrowheads denote dendrites; and small solid curved arrowheads denote
neuronal cell bodies. Bar, 10 µm. (B) Confocal merged image of a growth
cone. An enlarged merged image from the growth cone of the cell shown in A.
The merged staining includes the GFP-tau fluorescence (green), HuD
immunostaining (cyan) and GFP in situ hybridization (red) to yield a white
area of colocalization. Aggregation of tau granules is marked by a solid white
arrowhead; free HuD protein (cyan) is marked by an asterisk. Bar, 1 µm
(x20000 magnification).