Fig. 1.

PBs, SGs and related RNA granules in trypanosomes, flies and mammals. A and B, PBs are heterogeneous. A. Immunofluorescence for DCP1a; Ge-1/Hedls and Pacman/XRN1 in Drosophila Schneider S2R+ cells. Double-stained foci are frequent in the case of DCP1a and Ge-1, and infrequent for DCP1a and Pacman. In all cases, single-stained foci are highly frequent. Bars: 1 μm. B. The P-body components DCP1a and rck/p54 form separate foci in hippocampal neurons, and a fraction of them partially overlap. The dendritic cytoskeleton is stained in blue (kindly provided by Luciana Luchelli, Instituto Leloir, see also [56]). Bars: 1 μm. C. ER-stress induces the transient formation of SGs (red) in mammalian cells. In a fraction of cells SGs last longer than 8 h and fuse with PBs (green) (see also [16]). Bars: 5 μm. D. Polyadenylated RNA granules are induced in T. cruzi cells exposed to nutritional stress. Left, polyA granules contain the exoribonuclease XRNa (kindly provided by Alejandro Casola and Carlos Frasch, Universidad Nacional de San Martín, Argentina). Right, polyA granules are distinct from tRNA granules, which contain 5′ halves of tRNA molecules cleaved upon stress (kindly provided by A. Cayota, Institut Pasteur de Montevideo, Montevideo, Uruguay). Bars: 1 μm.