Figure 2.

IgD production increases during proliferative kidney disease infection. (A) Immunohistochemical detection of IgD⁺ cells in the kidney of parasite-infected (swelling grades 1–4) and parasite-naïve (swelling grade 0) fish. Representative images for fish with swelling grades 0, 1–2, and 3–4 are shown at 20× magnification (left images, scale bars = 40 µm) and at 100× magnification (right images, scale bars = 10 µm). IgD production in trunk kidney samples from each fish group was analyzed by Western blot. (B) Results from two representative individuals in each group are shown. (C) Abundance of IgD was quantified by optical densitometry and normalized against α-tubulin. Mean values in arbitrary units (A.U.) + SEM are shown (n = 4). Asterisks (*) denote significant differences (P < 0.05) between values obtained in grade 1–2 or grade 3–4 and grade 0 kidneys (analyzed by a two-tailed Student’s t-test).