Extended Data Fig. 9: Inheritance of injected labelled amyloids and detection of amyloid species across broad tissues.

(a) Isolated WT amyloids were labelled with an Alexa Fluor 647-NHS Ester, covalently marking amines (that is, proteins), and were then injected into gonads of WT worms where they are deposited into oocytes. Dashed line, germline. Bar, 20 µm. (b) Labelled amyloids are passed on through fertilization and detectable in fertilized oocytes. Dashed line, germline. Bar, 20 µm. (c) Labelled amyloids are stable in offspring where they can be detected in various tissues including in germlines, the intestine and head during L1 and L2 stages. Dashed lines: left, whole L1 stage worm; centre two, L2 germline; right, L2 head. Bars, 20 µm. (d) The labelled amyloids are stable into L3 germlines, the stage at which germ cell begin meiosis and differentiate to gametes. They are also still stable in the head, intestine, and body wall. Dashed line, germline. Bars, 20 µm. (e) Range of vulval phenotypes observed in F2 WT worms shifted to 20 °C after >30 generations of maintenance at 25 °C. n = 1724 worms observed over three separate experiments. Bar, 100 µm. (f) Substantial presence of punctate green autofluorescence and similar appearing Thioflavin T-stained bodies can be detected throughout development of wild type worms. Bars, 20 µm. (g) MSTR-1 is broadly expressed throughout development and displays modest nuclear localization within cells. Bar, 100 µm. (h) Green autofluorescent bodies in a fixed adult worm are costained by Amytracker 680, consistent with broader physiological prevalence of amyloid-like bodies in WT C. elegans. Specifically, gut granules, structures in the coelom, body wall and head, as well as punctate structures in embryos are strongly stained by Amytracker. However, significant permeability of Amytracker into the germline required extrusion and permeabilization of gonads, as displayed in Extended Data Fig. 6. Bars, 20 µm.