Extrinsic Repair of Injured Dendrites as a Paradigm for Regeneration by Fusion in Caenorhabditis elegans - PubMed

AFF-1::GFP protein dynamics during PVD dendrite regeneration. (A) Superresolution structured illumination microscopy image of aligned AFF-1::GFP (green) vesicles in the seam cells (left, white arrows) and AFF-1::GFP extracellular vesicles derived from the seam cells (right, white arrowheads) in intact wild-type animals. c, cell body. PVD is labeled in red. (B) Spinning disk confocal images of AFF-1::GFP expression inside and outside the seam cells (Se), and in the vulva (V) of an intact L4 animal (left). AFF-1::GFP (cyan) expression in the seam cells and in vesicles near the seam cells is shown in a two channels merged image (right, PVD in magenta;

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). Inset shows magnification of a single AFF-1::GFP vesicle near the seam cells (left, black arrowhead, numbered 1;

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). (C) AFF-1::GFP expression inside and outside the seam cells (Se), in the anchor cell (AC), and in the vulva (V) of a reconnected PVD L4 animal (left) is shown 2-hr postdendrotomy in a spinning disk confocal image. AFF-1::GFP is expressed in vesicles inside and outside of the seam cells, in the anchor cell (AC) and in VulA ring (see

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; right, blue arrowhead, site of reconnection). Inset shows magnification of area with multiple vesicles, two are labeled (2 and 3) and shown in (D and E). (D) Two AFF-1::GFP vesicles, numbered 2 and 3, are moving near the seam cells in a PVD dendrotomized animal. Four time points are shown (0, 20, 60, and 80 sec;

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). (E) Vesicle dynamics (1, 2, and 3) is demonstrated in a color-coded graph during 340 sec for vesicles 2 and 3 and 620 sec for vesicle number 1. The plot illustrates vast differences between AFF-1::GFP vesicle movements in animals with an intact PVD vs. AFF-1::GFP vesicles in PVD dendrotomized animals (

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and

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). (F) Dot plot of the number of AFF-1::GFP vesicles outside aff-1-expressing cells in animals with intact PVD vs. in animals with dendrotomized PVD. The graph demonstrates statistical significant difference between the mean number of aff-1::GFP vesicles outside aff-1-expressing organs such as seam cells, vulva, anchor cells, and the uterus. ***P = 0.001, statistics were calculated using the nonparametric Mann–Whitney test.