202515.fig.003a
(a)
202515.fig.003b
(b)
202515.fig.003c
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202515.fig.003d
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202515.fig.003e
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202515.fig.003f
(f)
Figure 3: Alcian blue (pH 2.5)/PAS staining of longitudinal sections cut through the body wall showing segmental muscle blocks (mus) with detail of adjacent mucus channels. (a) Low magnification of a histological section through the worm showing latero-lateral orientation of mucus channels (thin arrows). Note also the strong Alcian blue (pH 2.5) reaction in the cuticle (arrowhead) (Scale bar = 5 μm). (b) Low magnification of a histological section through the worm showing anterior/posterior orientation of channels perpendicular to laterals. Note presence of collection sinuses at channel intersections (thin arrows). The cuticle again stained strongly with Alcian blue (arrowhead) (Scale bar = 5 μm). (c) High magnification of lateral mucus channel showing intense staining of secretion with Alcian blue (pH 2.5)/PAS (large arrow). Note lightly stained secretory cells with basal nuclei lining the channel (arrowhead) (Scale bar = 1 μm). (d) High magnification of lateral mucus channel opening toward the integumental surface. Note secretory cells with basal nuclei (small arrow) and deeply stained mucoid secretion (large arrow). The cuticle is indicated by the arrowhead (Scale bar = 1 μm). (e) High magnification of outer cuticle adjacent to a muscle block (Mus) showing strong Alcian blue reactivity in the region (Scale bar = 1 μm). (f) Detail of glandular structure showing secretory cells exhibiting basal nucleus and granular apical cytoplasm (large arrow). Note viscous secretion associated with the luminal surface (arrowhead). (Scale bar = 1 μm).