| Küchler, S; Dettner, K; Kehl, S: Characterization of an obligate intracellular bacterium in midgut epithelium of bulrush bug Chilacis typhae (Heteroptera, Lygaeidae, Artheneinae), Applied and Environmental Microbiology, 270(9), 2869-2876 (2011) | |
| Abstract: Many members of the suborder Heteroptera have symbiotic bacteria, which are usually found extracellularly in specific sacs or tubular outgrowths of the midgut or intracellularly in mycetomes. In this study, we describe the second molecular characterization of a symbiotic bacterium in a monophagous, seed sucking stinkbug of the family Lygaeidae (sensu stricto). Chilacis typhae possess at the end of the 1st section of the midgut a structure, which is composed of circularly arranged, strongly enlarged midgut epithelial cells. It is filled with an intracellular endosymbiont. This "mycetocytic belt" might represent an evolutionary intermediate stage of the usual symbiotic structures found in stinkbugs. Phylogenetic analysis, based on the 16S rRNA and the groEL gene, show that the bacterium belong to the {gamma}-subdivision of the Proteobacteria and it revealed a phylogenetic relationship with a secondary bacterial endosymbiont of Cimex lectularius and free-living plant-pathogens such as Pectobacterium and Dickeya. The distribution and ultrastructure of the rod-shaped Chilacis endosymbiont were studied in adults and nymph stages using FISH and electron microscopy. The detection of symbionts at the anterior poles of developing eggs indicates that endosymbionts are transmitted vertically. A new genus and species name, Candidatus Rohrkolberia cinguli is proposed for this newly characterized clade of symbiotic bacteria. |
