Figure 4. Spiroplasma is completely absent from the neural tissue but heavily concentrates in other tissues of both male and female embryos.

High levels of bacteria (red) are located in the yolky interior of the cleavage blastoderm, while few bacteria can be seen around the cells of the epithelium (top panels). During later embryonic stages, no bacteria can be seen to overlap with the cells of the ventral nerve chord (insets in the bottom panels). During this time high levels of Spiroplasma are present both inside and outside the gut (bottom panels).