抄録
Oligonucleotide-probed in situ hybridization targeted to bacterial rRNAs was attempted to detect, visualize and characterize the intracellular symbiotic bacteria of aphids. Using the EUB338 probe that hybridizes universally with 16S rRNA of eubacteria, the primary and secondary intracellular symbionts of various aphids were successfully stained on tissue thin sections. When in situ hybridization was conducted with GAM42A and BET42A probes that are targeted to 23S rRNA of γ- and β-subdivision of the Proteobacteria, respectively, it was shown that the secondary symbionts of Cinara pini and Nippolachnus piri belong to the γ-subdivision of the Proteobacteria whereas that of Tetraneura radicicola is a member of the β-subdivision of the Proteobacteria. This is the first report on the phylogenetic affinity of the secondary intracellular symbionts of aphids. Because insect tissues have strong autofluorescence in general, non-fluorescent in situ hybridization using biotin- and digoxigenin-labelled probes was more suitable for detecting symbiotic bacteria in aphid tissue sections.
