1. Influence of symbionts on the development and physiology of the light organ.
Influence of symbionts on the development and physiology of the light organ. (A to C) Scanning electron microscopy (SEM) images of the superficial ciliated field close to the pore in 4-week-old aposymbiotic (A), Δlux mutant-colonized (B), and WT-colonized (C) squid (to locate the light organ, see the bottom right image in Fig. 1A and the orange circle). The red outline marks the surface covered by cilia (c); yellow arrowheads indicate the locations of pores. The scale bar in panel A is suitable for all images in panels A to C and F to H. (D and E) Statistics on surface structures of the light organ at 4 weeks, namely, the number of visible pores on each side of the light organ (D) and the cilium index, which takes into account the area covered by cilia and the density of long cilia, averaged per light organ (mean ± SE, n = 4 or 5; *, P < 0.05, Kruskal-Wallis test with Dunn’s multiple-comparison test) (E). (F to H) Images of histological sections through the host crypts of 4-week-old Apo (F), Δlux mutant-colonized (G), and WT-colonized (H) squid. The collapse of the empty crypt lumen (G) is a technical artifact that is independent of the infection status. cl, crypt lumen; n, nucleus; r, reflector; Vf, Vibrio fischeri cells. Green arrows mark the representative distances between nuclei under different conditions of colonization. (I to J) Statistics on cellular features of the light organ crypts, namely, the central core width normalized by lens width (mean ± SE, n = 3; *, P < 0.05, Kruskal-Wallis test with Dunn’s multiple-comparison test) (I) and the distance between nuclei in epithelial cells surrounding the crypt lumen (mean ± SE, n = 21; ***, P < 0.001 by one-way ANOVA with Tukey’s HSD multiple-comparison test) (J).
Natacha Kremer et al. mSystems 2018; doi: /mSystems