Fig. 1: Me31B and Imp condensate into larger cytoplasmic granules in aged brains.

a–j Cell bodies of MB γ neurons imaged from 1–2 day- (a, c, e, g, i; young), or 37–38 day- (b, d, f, h, j; aged) old brains. Brains were stained with anti-Me31B (a, b) or anti-Imp (c, d) antibodies. Me31B-GFP (e, f), GFP-Imp (g, h) and mCherry-Rin (i, j) were expressed from their endogenous locus. Note that dark nuclei occupy most of the soma, and that the cytoplasmic signal is restricted to the cell periphery. Scale bar: 5 μm. k Mean granular:cytoplasmic intensity ratio (partition coefficient) in brains of 1–2 day-old flies. Each data point represents the mean value of one replicate. At least 10 fields were analyzed per replicate. Two to three independent experiments were quantified per condition. l Normalized sizes of Me31B-containing granules in neurons of 1–2 day- (young) and 37–38 day- (aged) old brains. Frequency distributions are plotted for one replicate, but three were performed (see Supplementary Fig. 1a). ***P < 0.001 (unpaired t-test on individual data points). m Normalized numbers of Me31B-containing granules (per surface area) in MB γ neurons of 1–2 day- (young) and 37–38 day- (aged) old brains. Three replicates were performed and the mean value of each is indicated as a triangle. Data points were color-coded based on the replicate they belong to. In l, m, individual data points were collected from brains immunostained with anti-Me31B antibodies and normalized to the young condition. ***P < 0.001 (unpaired, two-sided t-test on individual data points). n Intra-granule concentration of Me31B (orange) and Imp (green) in 1–2 day- (young) and 37–38 day- (aged) old brains. Concentrations were estimated by measuring the mean intensity of Me31B-GFP and GFP-Imp signals within masks of corresponding granules. Three replicates were performed and the mean value of each is indicated as a triangle. The distribution of individual granule mean intensities is shown for one replicate only. ***P < 0.001 (unpaired, two sided t-test on individual data points). o Imp mean partition coefficients upon aging. Each data point represents the average of mean values obtained from three independent replicates. Error bars correspond to s.e.m. Source data are provided as a Source Data file.