FISH detection of Wolbachia in circulating haemocytes and haematopoietic organs.

In infected animals, Wolbachia (in red) colonized many haemocytes (A, B) and the central area (*) as well as the cortex (**) of the haematopoietic organ (C), although groups of cells remained uncolonized (Arrowheads, D–F). The control uninfected animals presented only rare Wolbachia-like artefacts (haemocytes, G–H, haematopoietic organ, I). A–C, G–H: red: Wolbachia, green: Actin; blue: Nuclei. A, B, G, H: average intensity Z-projections. B and H: Close-ups. D–F: 3D analysis (ImageJ 3D viewer) of image C. D: tilted volume rendering of Wolbachia (red) and the nuclei (turquoise) in the central area extracted from the Z-stack. E and F: volume rendering of Wolbachia (grey-scale) from the whole haematopoietic organ. E: front view corresponding to image C, F: tilted view (180°).