Figure 6.

The phagocyte subpopulation of coelomocytes expresses the SpTransformer (SpTrf) proteins. (A) The standard SpTrf protein structure has an N-terminal leader (red), a glycine-rich region (orange), a histidine-rich region (blue), and a C-terminal region (gray). This figure is reprinted from Ref. (1). (B) A small phagocyte has SpTrf proteins within the cell and on the cell surface. (C) A large polygonal phagocyte has SpTrf proteins in small vesicles surrounding the nucleus. (D) A few discoidal phagocytes have a few, perinuclear vesicles containing SpTrf proteins. (E) Red spherule cells and (F) vibratile cells do not express SpTrf proteins. (G) A cross section of gut shows SpTrf⁺ cells within the columnar epithelium that are likely coelomocytes. The gut lumen is at the top of the image and the coelomic cavity is toward the bottom. (H) Numerous SpTrf⁺ cells are present within the axial organ, and are likely coelomocytes. Fluorescence microscopy was used to generate images (B,D–G), and confocal microscopy was used for (C,H). Images (B,C) were contributed by A. J. Majeske. (D–F) were reproduced from Ref. (41) with permission. Copyright 2014. The American Association of Immunologists, Inc. (F,G) were reprinted from Ref. (42). Scale bars are 10 µm for (B–F) and are 100 µm for (G,H).