title: Bacterial symbionts of the leafhopper Evacanthus interruptus (Linnaeus, 1758) (Insecta, Hemiptera, Cicadellidae: Evacanthinae).
abstract: Plant sap-feeding hemipterans harbor obligate symbiotic microorganisms which are responsible for the synthesis of amino acids missing in their diet. In this study, we characterized the obligate symbionts hosted in the body of the xylem-feeding leafhopper Evacanthus interruptus (Cicadellidae: Evacanthinae: Evacanthini) by means of histological, ultrastructural and molecular methods. We observed that E. interruptus is associated with two types of symbiotic microorganisms: bacterium 'Candidatus Sulcia muelleri' (Bacteroidetes) and betaproteobacterium that is closely related to symbionts which reside in two other Cicadellidae representatives: Pagaronia tredecimpunctata (Evacanthinae: Pagaronini) and Hylaius oregonensis (Bathysmatophorinae: Bathysmatophorini). Both symbionts are harbored in their own bacteriocytes which are localized between the body wall and ovaries. In E. interruptus, both Sulcia and betaproteobacterial symbionts are transovarially transmitted from one generation to the next. In the mature female, symbionts leave the bacteriocytes and gather around the posterior pole of the terminal oocytes. Then, they gradually pass through the cytoplasm of follicular cells surrounding the posterior pole of the oocyte and enter the space between them and the oocyte. The bacteria accumulate in the deep depression of the oolemma and form a characteristic 'symbiont ball'. In the light of the results obtained, the phylogenetic relationships within modern Cicadomorpha and some Cicadellidae subfamilies are discussed.
authors.affiliation: Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland. teresa.szklarzewicz@uj.edu.pl.
authors.forename: Teresa
authors.initials: T
authors.lastname: Szklarzewicz
authors.affiliation: Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31-016, Kraków, Poland. grzywacz@isez.pan.krakow.pl.
authors.forename: Beata
authors.initials: B
authors.lastname: Grzywacz
authors.affiliation: Department of Invertebrate Zoology and Parasitology, Faculty of Biology, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland. jacek.szwedo@biol.ug.edu.pl.
authors.forename: Jacek
authors.initials: J
authors.lastname: Szwedo
authors.affiliation: Department of Developmental Biology and Morphology of Invertebrates, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387, Kraków, Poland. a.michalik@uj.edu.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Michalik
mesh_terms: D000818:Animals; D041963:Bacteroidetes / Q000502:physiology*; D020562:Betaproteobacteria / Q000502:physiology*; D005260:Female; D005798:Genes, Bacterial; D006430:Hemiptera / Q000382:microbiology* / Q000648:ultrastructure; D058889:Molecular Typing; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013559:Symbiosis
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Bacteriocytes; Cicadellidae; Sulcia; Symbiotic microorganisms; Transovarial transmission of symbionts