Fig. 6. mRNA localization and compaction within germ granules depend on their translation.

a, b STED imaging of immuno-smFISH of wild-type (top) and png¹⁰⁵⁸ (bottom) embryos with anti-Osk antibody (magenta) as a marker of germ granule and smFISH probes (green) against nos (a) and gcl (b) mRNAs. c, d Percentage of localization of nos (c) and gcl (d) mRNA foci in wild-type and png¹⁰⁵⁸ mutant embryos, in the core (black), in and at the surface of the shell (grey), and at the immediate periphery (white) of germ granules from images as in (a, b). **p < 0.01, ****p < 0.0001 using the χ² test. p = 0.0031 in (c) and 1.75 × 10⁻²² in (d). e STED images of smFISH against nos 5′end (5′-nos, magenta) and 3′end (3′-nos, green) in wild-type and png¹⁰⁵⁸ mutant embryos. f STED images of smFISH against nos 5′end (5′-nos, magenta) and 3′end (3′-nos, green) in wild-type stage 14 oocytes. g Violin plots showing distance distribution of colocalizing foci (5′-nos to 5′-nos and 3′-nos to 3′-nos) and 5′end to 3′end distances for nos mRNAs at germ granules in wild-type and png¹⁰⁵⁸ mutant embryos, from STED images as in (e). Dashed lines inside the violin plots show first quartile, median, and third quartile. Median distances are indicated on the right. ns: non-significant, ****p < 0.0001 using unpaired two-tailed Student’s t-test. p = 0.2 between 5′-nos/5′-nos and 3′-nos/3′-nos, p = 3.5 × 10⁻¹⁹¹ between 5′-nos/5′-nos and 5′-nos/3′-nos in wt, p = 1.3 × 10⁻²¹⁸ between 3′-nos/3′-nos and 5′-nos/3′-nos in wt and p = 4.5 × 10⁻⁵⁸ between 5′-nos/3′-nos in wt and png^−/−. The number of measured distances is indicated (n). h Measurement of the distance between nos 5′end foci and the edge of nos 3′end foci in wild-type embryos, png¹⁰⁵⁸ embryos, and wild-type stage 14 oocytes (st14), from images as in (e, f). The histogram shows the percentage of nos 5′end foci in each distance class. i Percentage of nos 5′end foci overlaps with nos 3′end foci in wild-type embryos, png¹⁰⁵⁸ embryos and wild-type stage 14 oocytes (st14). ns: non-significant, ****p < 0.0001 using the χ² test. p = 2.64 × 10⁻¹²⁹ between wt and png^−/−, p = 1.79 × 10⁻¹⁶⁷ between wt embryos and stage 14 oocytes, and p = 0.15 between png^−/− embryos and stage 14 oocytes. Scale bars: 1 µm. Source data are provided as a Source Data file.