Figure 1
(a) Light microscopic micrograph at low magnification of a longitudinal section of the mealybug T. mannipara. The bacteriome (outlined in white) occupies a considerable part of the insect abdomen. (b) Light microscopic micrograph at higher magnification of the bacteriome. One of the bacteriocytes is outlined in white. The bacteriocytes present central nuclei with large nucleoli, indicating high cellular activity. Individual bacteriocytes contain up to seven enlarged bacterial symbionts (Tremblaya) in highly amorphous shapes, which themselves harbor several polymorphic bacteria (Trabutinella). (c) Transmission electron microscopic observation of a single host bacterium (Tremblaya) containing several bacteria (Trabutinella) within its cytoplasm. (d) Localization of ‘Candidatus Trabutinella endobia’ within ‘Ca. T. phenacola’ cells as seen with fluorescence in situ hybridization. A general bacterial probe (in green), a gammaproteobacterial probe (in red) and a Trabutinella-specific probe (in blue) were used; cells of Trabutinella appear white–purple, Tremblaya green.
