Figure 1From: Genome degeneration affects both extracellular and intracellular bacterial endosymbiontsThe diverse locations of endosymbionts in insects. The locations of the endosymbionts are shown in these schematic diagrams by red dots. (a) 1, The bee-wolf Philanthus triangulum harbors endosymbionts within the antennal segments [5]. 2, Bacteriocytes carrying primary endosymbionts can be localized within the midgut epithelium (carpenter ants) or in an organ-like structure called the bacteriome, which comprises a collection of bacteriocytes, located adjacent to the midgut (for example, in weevils, aphids and whiteflies) [6,7]. 3, Primary endosymbionts may also be present in the ovaries to ensure vertical transmission [6,7]. 4, Cockroaches and the termite Mastotermes darwiniensis harbor endosymbionts in a bacteriome within the fat body [13]. (b) Acanthosomatid stinkbugs harbor extracellular endosymbionts in crypts in a specialized part of the midgut (m4). The midgut is differentiated into four parts (m1 to m4) whereas the hindgut has a simple structure [4]. (c) Termites harbor a complex symbiotic community in their hindgut lumen [2]. In contrast to stinkbugs, the hindgut but not the midgut is differentiated into several parts with differing chemical milieux. MT, malpighian tubules.Back to article page