Fig. 6. Immunocytochemical localization of NO synthase in land crab Y-organs. Sections of Y-organ were incubated with either a universal anti-NOS rabbit antibody (A, C and D; 1:2000 dilution) or a non-immune rabbit antibody (B; 1:2000 dilution); detection used BCIP/NBT (see Materials and methods). (A) NOS localization in the cytoplasm and nuclei of Y-organ (YO) cells and nuclei in some cells in the adjacent hemolymph space (HS) and connective tissue (CT). (B) Control serial section adjacent to A showing no specific antibody binding in Y-organ tissue. (C) NOS localization in the nuclei of some connective tissue cells. (D) NOS localization in the tendinous cells (TC), which anchor connective tissue to the cuticle (C). BC, branchial chamber. Scale bars, 200 µm.