Fig. 2.

Infection specificity of bacterial species in the gut symbiotic organ. (A) Infection ability of diverse bacterial species to the gut symbiotic organ. Five days after oral administration, the colonization level in M4 was evaluated by CFU counting. (B) Infection initiation process visualized by confocal microscopy. The infecting bacteria were labeled with GFP. Note that only Pandoraea (P. norimbergensis), PBE (B. fungorum), and SBE (B. insecticola) pass through the sorting organ, the constricted region. Arrows indicate an infection thread invading from M3 to M4B through the constricted region. Abbreviations: CR, constricted region; M3, midgut third section; M4B, M4 bulb.