Molecular characterization, ultrastructure, and transovarial transmission of Tremblaya phenacola in six mealybugs of the Phenacoccinae subfamily (Insecta, Hemiptera, Coccomorpha)

Mealybugs (Hemiptera, Coccomorpha: Pseudococcidae) are plant sap-sucking insects which require close association with nutritional microorganisms for their proper development and reproduction. Here, we present the results of histological, ultrastructural, and molecular analyses of symbiotic systems of six mealybugs belonging to the Phenacoccinae subfamily: Phenacoccus aceris, Rhodania porifera, Coccura comari, Mirococcus clarus, Peliococcus calluneti, and Ceroputo pilosellae.Molecular analyses based on bacterial 16S rRNA genes have revealed that all the investigated species of Phenacoccinae are host to only one type of symbiotic bacteria—a large pleomorphic betaproteobacteria—Tremblaya phenacola. In all the species examined, bacteria are localized in the specialized cells of the host-insect termed bacteriocytes and are transovarially transmitted between generations. The mode of transovarial transmission is similar in all of the species investigated. Infection takes place in the neck region of the ovariole, between the tropharium and vitellarium. The co-phylogeny between mealybugs and bacteria Tremblaya has been also analyzed

Fungal Associates of Soft Scale Insects (Coccomorpha: Coccidae)

Ophiocordyceps fungi are commonly known as virulent, specialized entomopathogens; however, recent studies indicate that fungi belonging to the Ophiocordycypitaceae family may also reside in symbiotic interaction with their host insect. In this paper, we demonstrate that Ophiocordyceps fungi may be obligatory symbionts of sap-sucking hemipterans. We investigated the symbiotic systems of eight Polish species of scale insects of Coccidae family: Parthenolecanium corni, Parthenolecanium fletcheri, Parthenolecanium pomeranicum, Psilococcus ruber, Sphaerolecanium prunasti, Eriopeltis festucae, Lecanopsis formicarum and Eulecanium tiliae. Our histological, ultrastructural and molecular analyses showed that all these species host fungal symbionts in the fat body cells. Analyses of ITS2 and Beta-tubulin gene sequences, as well as fluorescence in situ hybridization, confirmed that they should all be classified to the genus Ophiocordyceps. The essential role of the fungal symbionts observed in the biology of the soft scale insects examined was confirmed by their transovarial transmission between generations. In this paper, the consecutive stages of fungal symbiont transmission were analyzed under TEM for the first time

Bacterial symbionts of the leafhopper "Evacanthus interruptus" (Linnaeus, 1758) (Insecta, Hemiptera, Cicadellidae : Evacanthinae)

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

Phylogenetic relationship of Japanese Podismini species (Orthoptera: Acrididae: Melanoplinae) inferred from a partial sequence of cytochrome c oxidase subunit I gene

Members of the tribe Podismini (Orthoptera: Acrididae: Melanoplinae) are distributed mainly in Eurasia and the western and eastern regions of North America. The primary aim of this study is to explore the phylogenetic relationship of Japanese Podismini grasshoppers by comparing partial sequences of cytochrome c oxidase subunit I (COI) mitochondrial gene. Forty podismine species (including nineteen Japanese species) and thirty-seven species from other tribes of the Melanoplinae (Dactylotini, Dichroplini, Melanoplini, and Jivarini) were used in the analyses. All the Japanese Podismini, except Anapodisma, were placed in a well-supported subclade. However, our results did not correspond with the classification on the basis of morphological similarity for the status of Tonkinacridina. This group of Japanese species constituted a single clade with other species of Miramellina and Podismina, while Eurasian continental species of Tonkinacridina were placed in other separate clades. This incongruence might have resulted from historical migratory events between continent and ancient islands and subsequent convergent/parallel evolution in morphology. Some remarks on phylogenetic positions in Podismini and other tribes were also made in terms of reconstructed phylogeny

New insights into the genetic diversity of the Balkan bush-crickets of the Poecilimon ornatus group (Orthoptera: Tettigoniidae)

The Balkan Peninsula is treated as a hotspot of biodiversity with over 40% of European bush-crickets occurring there. Poecilimon Fischer, 1853 is one of the largest Palaearctic orthopteran genera containing several species groups. One of them is the Poecilimon ornatus group (Schmidt, 1850) with 13 species and 5 subspecies. Among the group, the Poecilimon affinis complex is designated as consisting of P. pseudornatus Ingrisch & Pavićević, 2010, P. nonveilleri Ingrisch & Pavićević, 2010, and five subspecies of P. affinis (Frivaldszky, 1868). The aim of this study is to reconstruct the phylogenetic relationships among taxa of the P. ornatus group and to elucidate the position of taxa related to the P. affinis complex. Molecular phylogeny supported the monophyly of the P. ornatus group and showed that their ancestor probably originated in the southern Balkans. The underlying processes are thought to be six dispersals and five vicariance events linked to geological events and climate changes in the Pleistocene. The species delimitation analysis showed mostly nine hypothetical species among the group

Synthesis, Modification and Biological Activity of Diosgenyl β-d-Glycosaminosides: An Overview

Saponins are a structurally diverse class of natural glycosides that possess a broad spectrum of biological activities. They are composed of hydrophilic carbohydrate moiety and hydrophobic triterpenoid or steroid aglycon. Naturally occurring diosgenyl glycosides are the most abundant steroid saponins, and many of them exhibit various pharmacological properties. Herein, we present an overview of semisynthetic saponins syntheses–diosgenyl β-d-glycosaminosides (d-gluco and d-galacto). These glycosides possess a 2-amino group, which creates great possibilities for further modifications. A wide group of glycosyl donors, different N-protecting groups and various reaction conditions used for their synthesis are presented. In addition, this paper demonstrates the possibilities of chemical modifications of diosgenyl β-d-glycosaminosides, associated with functionalisation of the amino group. These provide N-acyl, N-alkyl, N,N-dialkyl, N-cinnamoyl, 2-ureido and 2-thiosemicarbazonyl derivatives of diosgenyl β-d-glycosaminosides, for which the results of biological activity tests (antifungal, antibacterial, anti-cancer and hemolytic) are presented