Proctolin in the brain and ganglia of Triatoma infestans (Hemiptera: Reduviidae)

The distribution of proctolin in the central nervous system of the hemipteran bug, Triatoma infestans, was studied by immunohistochemistry using the sensitive avidin‐biotin technique combined with nickel salt intensification of the reaction product. Proctolin was present in cells and fibers of the brain and ganglia. In the brain, protocerebral proctolin‐immunoreactive cell bodies were found in the pars intercerebralis, the optic lobes, and the lateral soma rind. The deutocerebrum showed positive somata in relation to the antennal motor center and the tritocerebrum had intense immunoreactive fibers but few positive cells. Proctolin‐immunoreactive cell bodies of different sizes were observed in the subesophageal ganglion. Large cell bodies were found mainly rostrally and beaded positive processes were present around the ventral border of the esophageal foramen and in the rostrolateral neuropil of this ganglion. Small‐ to medium‐sized positive somata were found in the posterior part of the prothoracic ganglion; some of these cells were sending immunoreactive processes to the central neuropil. The meso‐metathoracic‐abdominal ganglionic mass showed positive cells in all the neuromeres, where some of them were large and had thick immunoreactive granules. The results show that the labeling pattern of proctolin‐like immunoreactivity in Triatoma i. appears to be widespread and unique for its central nervous system. It is suggested that proctolin may serve neuroendocrine, integrative, and motor functions in the brain of T. infestans. J. Morphol. 240:39–47, 1999. © 1999 Wiley‐Liss, Inc.     

Insect phylogenomics: results, problems and the impact of matrix composition

In this study, we investigated the relationships among insect orders with a main focus on Polyneoptera (lower Neoptera: roaches, mantids, earwigs, grasshoppers, etc.), and Paraneoptera (thrips, lice, bugs in the wide sense). The relationships between and within these groups of insects are difficult to resolve because only few informative molecular and morphological characters are available. Here, we provide the first phylogenomic expressed sequence tags data ('EST': short sub-sequences from a c(opy) DNA sequence encoding for proteins) for stick insects (Phasmatodea) and webspinners (Embioptera) to complete published EST data. As recent EST datasets are characterized by a heterogeneous distribution of available genes across taxa, we use different rationales to optimize the data matrix composition. Our results suggest a monophyletic origin of Polyneoptera and Eumetabola (Paraneoptera + Holometabola). However, we identified artefacts of tree reconstruction (human louse Pediculus humanus assigned to Odonata (damselflies and dragonflies) or Holometabola (insects with a complete metamorphosis); mayfly genus Baetis nested within Neoptera), which were most probably rooted in a data matrix composition bias due to the inclusion of sequence data of entire proteomes. Until entire proteomes are available for each species in phylogenomic analyses, this potential pitfall should be carefully considered.     

Evidence for Carboniferous origin of the order Mantodea (Insecta: Dictyoptera) gained from forewing morphology

Homologies of the forewing venation pattern of the order Mantodea (Insecta: Dictyoptera) consistent with the accepted insect wing venation groundplan are proposed. A comparative morphological analysis was carried out based on a broad taxonomic sample of extant taxa. Besides macromorphological aspects, focus is given to the pattern of the tracheal system as a basis for establishing primary homologies. All extant praying mantids exhibit a composite stem composed of the posterior radius (RP) and the media (M) and most praying mantids exhibit a fusion of the anterior branch of RP + M with the anterior radius (RA). The wing venation of the species ?Mesoptilus dolloi, previously assigned to the polyphyletic fossil assemblage ‘Protorthoptera’, is re‐interpreted in the light of the new homology statement. Our interpretation suggests that it is a putative stem‐Mantodea, as are some other ‘protorthopterous’ taxa. This hypothesis implies that the total‐group Mantodea arose as soon as the Late Carboniferous, i.e. about 175 million years earlier than previously estimated. This analysis contributes to the view that most of the Late Carboniferous ‘Protorthoptera’ are stem‐representatives of the major polyneopteran clades (e.g. cockroaches, grasshoppers and crickets, rock‐crawlers), suggesting a survivorship of several main Pterygota lineages at the end‐Permian extinction event higher than previously expected. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 79–113.     

The adipokinetic hormone of Mantodea in comparison to other Dictyoptera

Six species of the order Mantodea (praying mantises) are investigated for the presence and sequence of putative adipokinetic hormones (AKHs). The selected species span a wide evolutionary range of various families and subfamilies of the clade Mantodea. The corpora cardiaca of the different species are dissected, methanolic extracts prepared, peptides separated by liquid chromatography, and AKHs detected and sequenced by ion trap mass spectrometry. All six species investigated contain an octapeptide with the primary structure pGlu‐Val‐Asn‐Phe‐Thr‐Pro‐Asn‐Trp amide, which is code‐named Emppe‐AKH and had been found earlier in three other species of Mantodea. Conspecific bioassays with the species Creoboter sp. (family Hymenopodidae) reveal an adipokinetic but not a hypertrehalosemic function of Emppe‐AKH. Comparison with other members of the Dictyoptera (cockroaches, termites) show that Emppe‐AKH is only found in certain termites, which have been recently placed into the Blattaria (cockroaches) as sister group to the family Cryptocercidae. Termites and cockroaches both show biodiversity in the sequence of AKHs, and some cockroach species even contain two AKHs. In contrast, all praying mantises—irrespective of their phylogenetic position—synthesize uniformly only one and the same octapeptide Emppe‐AKH.     

A proteomic approach for studying insect phylogeny: CAPA peptides of ancient insect taxa (Dictyoptera, Blattoptera) as a test case

Background  

Neuropeptide ligands have to fit exactly into their respective receptors and thus the evolution of the coding regions of their genes is constrained and may be strongly conserved. As such, they may be suitable for the reconstruction of phylogenetic relationships within higher taxa. CAPA peptides of major lineages of cockroaches (Blaberidae, Blattellidae, Blattidae, Polyphagidae, Cryptocercidae) and of the termite Mastotermes darwiniensis were chosen to test the above hypothesis. The phylogenetic relationships within various groups of the taxon Dictyoptera (praying mantids, termites and cockroaches) are still highly disputed.     

MALDI‐TOF‐MS‐based species identification and typing approaches in medical mycology

MALDI‐TOF MS‐based species identification has found its place in many clinical routine diagnostic laboratories over the past years. Several well‐established commercial systems exist and these allow precise analyses not only among bacteria, but also among clinically important yeasts. This methodology shows higher precision than biochemical and microscopic methods at significantly reduced turnaround times. Furthermore, the differentiation of different filamentous fungi including most dermatophytes and zygomycetes has been established. The direct identification of yeasts from blood culture bottles will be possible in a routine fashion with new standardized procedures. In addition to species identification, the MALDI‐TOF MS technology offers several further possibilities, like assays to detect or predict resistance phenotypes in fungi as well as subtyping approaches to detect clinically relevant subgroups. The differences between the commercial systems are discussed with respect to fungi and an overview of their performances provided. Factors influencing outcome of MALDI‐TOF‐based species identification are discussed.     

螳螂种群增长制约因素分析

在自然界中,螳螂种群数量的增长受到多种因素的制约。作者通过野外调查和实验室饲养观察,以及对国内外相关资料的查阅,对这些主要制约因素逐一进行了分析和归纳。在影响螳螂分布与制约种群数量增长的这些因素中,自然条件中的温度是关键的制约因素,食物、天敌、自残行为、人类活动等是重要的制约因素。     

Cockroach homologs of praying mantis peripheral auditory system components

This study identifies the cuticular metathoracic structures in earless cockroaches that are the homologs to the peripheral auditory components in their sister taxon, praying mantids, and defines the nature of the cuticular transition from earless to eared in the Dictyoptera. The single, midline ear of mantids comprises an auditory chamber with complex walls that contain the tympana and chordotonal transduction elements. The corresponding area in cockroaches, between the furcasternum and coxae, has many socketed hairs arranged in discrete fields and the Nerve 7 chordotonal organ, the homolog of the mantis tympanal organ. The Nerve 7 chordotonal organ attaches at the apex of the lateral ventropleurite (LVp), which has the same shape and general structure as an auditory chamber wall. High-speed video shows that when the coxa moves toward the midline, the LVp rotates medially to stimulate socketed hairs, and also moves like a triangular hinge giving the chordotonal organ maximal in-out stimulation. Formation of the mantis auditory chamber from the LVp and adjacent structures would involve only enlargement, a shift toward the midline, and a mild rotation. Almost all proprioceptive function would be lost, which may constitute the major cost of building and maintaining the mantis ear. Isolation from leg movement dictates the position of the mantis ear in the midline and the rigid frame, formed by the cuticular knobs, which protects the chordotonal organs.     

Rapid identification and characterization of Vibrio species using whole‐cell MALDI‐TOF mass spectrometry

Aims: Vibrio identification by means of traditional microbiological methods is time consuming because of the many biochemical tests that have to be performed to distinguish closely related species. This work aimed at evaluating the use of MALDI‐TOF mass spectrometry for the rapid identification of Vibrio (V.) spp. as an advantageous application to rapidly discriminate the most important Vibrio spp. and distinguish Vibrio spp. from closely related bacterial species like Photobacterium damselae and Grimontia hollisae and other aquatic bacteria like Aeromonas spp. Methods and Results: Starting from sub‐colony amounts of pure cultures grown on agar plates, a very simple sample preparation procedure was established and combined with a rapid and automated measurement protocol that allowed species identification within minutes. Closely related species like Vibrio alginolyticus and Vibrio parahaemolyticus or Vibrio cholerae and Vibrio mimicus could thus be differentiated by defining signatures of species‐identifying biomarker ions (SIBIs). As a reference method for species designation and for determination of relationships between strains with molecular markers, partial rpoB gene sequencing was applied. Conclusions: The MALDI‐TOF MS‐based method as well as the rpoB sequence‐based approach for Vibrio identification described in this study produced comparable classification results. The construction of phylogenetic trees from MALDI‐TOF MS and rpoB sequences revealed a very good congruence of both methods. Significance and Impact of the Study: Our results suggest that whole‐cell MALDI‐TOF MS‐based proteometric characterization represents a powerful tool for rapid and accurate classification and identification of Vibrio spp. and related species.     

Eusociality and the success of the termites: insights from a supertree of dictyopteran families

Sociality in insects may negatively impact on species richness. We tested whether termites have experienced shifts in diversification rates through time. Supertree methods were used to synthesize family‐level relationships within termites, cockroaches and mantids. A deep positive shift in diversification rate is found within termites, but not in the cockroaches from which they evolved. The shift is responsible for most of their extant species richness suggesting that eusociality is not necessarily detrimental to species richness, and may sometimes have a positive effect. Mechanistic studies of speciation and extinction in eusocial insects are advocated.     

Usefulness and accuracy of MALDI‐TOF mass spectrometry as a supplementary tool to identify mosquito vector species and to invest in development of international database

Arthropod‐borne diseases are important causes of morbidity and mortality. The identification of vector species relies mainly on morphological features and/or molecular biology tools. The first method requires specific technical skills and may result in misidentifications, and the second method is time‐consuming and expensive. The aim of the present study is to assess the usefulness and accuracy of matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) as a supplementary tool with which to identify mosquito vector species and to invest in the creation of an international database. A total of 89 specimens belonging to 10 mosquito species were selected for the extraction of proteins from legs and for the establishment of a reference database. A blind test with 123 mosquitoes was performed to validate the MS method. Results showed that: (a) the spectra obtained in the study with a given species differed from the spectra of the same species collected in another country, which highlights the need for an international database; (b) MALDI‐TOF MS is an accurate method for the rapid identification of mosquito species that are referenced in a database; (c) MALDI‐TOF MS allows the separation of groups or complex species, and (d) laboratory specimens undergo a loss of proteins compared with those isolated in the field. In conclusion, MALDI‐TOF MS is a useful supplementary tool for mosquito identification and can help inform vector control.     

Similar yet different: differential response of a praying mantis to ant‐mimicking spiders

Batesian mimics typically dupe visual predators by resembling noxious or deadly model species. Ants are unpalatable and dangerous to many arthropod taxa, and are popular invertebrate models in mimicry studies. Ant mimicry by spiders, especially jumping spiders, has been studied and researchers have examined whether visual predators can distinguish between the ant model, spider mimic and spider non‐mimics. Tropical habitats harbour a diverse community of ants, their mimics and predators. In one such tripartite mimicry system, we investigated the response of an invertebrate visual predator, the ant‐mimicking praying mantis (Euantissa pulchra), to two related ant‐mimicking spider prey of the genus Myrmarachne, each closely mimicking its model ant species. We found that weaver ants (Oecophylla smaragdina) were much more aggressive than carpenter ants (Camponotus sericeus) towards the mantis. Additionally, mantids exhibited the same aversive response towards ants and their mimics. More importantly, mantids approached carpenter ant‐mimicking spiders significantly more than often that they approached weaver ant‐mimicking spiders. Thus, in this study, we show that an invertebrate predator, the praying mantis, can indeed discriminate between two closely related mimetic prey. The exact mechanism of the discrimination remains to be tested, but it is likely to depend on the level of mimetic accuracy by the spiders and on the aggressiveness of the ant model organism.     

Electrophysiological investigation of the antennal heart of Periplaneta americana and its reactions to proctolin

Some physiological parameters of the antennal heart, an accessory circulatory organ in the head of Periplaneta americana and the effect of the neuropeptide proctolin on it were investigated. The beat frequency of the antennal heart in vivo or semiisolated is about 2–3 times slower than that of the dorsal vessel and not coordinated with the latter. The extracellular ECG of the antennal heart has a simple biphasic shape with a total duration of 588.7 ± 38.2 ms. Intracellularly recorded parameters showed characteristics typical of myogenic rhythmicity: a slow depolarization with a rate of rise of 7.5 ± 0.7 mV/s, followed by an action potential of 54.9 ± 1.2 mV with a relatively long duration of 201.6 ± 10.8 ms, absence of overshoots and resistance to TTX. Proctolin produced a marked enhancement of the frequency of beat of the antennal heart up to about 400% with a high sensitivity (threshold concentrations: 5·10^?9M). The dose-response curve shows a linear relationship between the logarithm of the concentration and the percentage increase in beat frequency. The electrical event most influenced by proctolin was the slow pacemaker depolarization, whose rate of rise was enhanced up to 240%. The action potential remained unchanged; the depolarization of the resting potential was very small and the input resistance did not change. The antennal heart responds to neurohormone D, another neuropeptide in insects, in a similar way as it does to proctolin. The mode of action of proctolin on the antennal heart is discussed in comparison to that found in other systems.     

Concurrent Proteomic Fingerprinting and Molecular Analysis of Cyathostomins

Rapid, cost‐effective, efficient, and reliable helminth species identification is of considerable importance to understand host–parasite interactions, clinical disease, and drug resistance. Cyathostomins (Nematoda: Strongylidae) are considered to be the most important equine parasites, yet research on this group is hampered by the large number of 50 morphologically differentiated species, their occurrence in mixed infections with often more than 10 species and the difficulties associated with conventional identification methods. Here, MALDI‐TOF MS, previously successfully applied to identify numerous organisms, is evaluated and compared with conventional and molecular genetic approaches. A simple and robust protocol for protein extraction and subsequent DNA isolation allowing molecular confirmation of proteomic findings is developed, showing that MALDI‐TOF MS can discriminate adult stages of the two closely related cyathostomin species Cylicostephanus longibursatus and Cylicostephanus minutus. Intraspecific variability of proteomic profiles within morphospecies demonstrated an identification of morphospecies with an accuracy of close to 100%. In contrast, three genospecies within C. minutus and sex‐specific profiles within both morphospecies could not be reliably discriminated using MALDI‐TOF MS. In conclusion, MALDI‐TOF MS complemented by the molecular protocol is a reliable and efficient approach for cyathostomin species identification.     

Partial characterization and isolation of earwig `allatostatins'': biological activities in earwigs and cockroaches

Allatostatins are a family of neuropeptides first isolated from the cockroach, Diploptera punctata, that inhibit juvenile hormone production in that species (but do not do so in earwigs), and inhibit hindgut muscle contractions in some insects, including the earwig, Euborellia annulipes. We examined whether material from earwig brains is similar to cockroach allatostatins biochemically, immunologically and physiologically. Brain extracts from adult female earwigs were separated by high performance liquid chromatography (HPLC), followed by radioimmunoassay using antibodies to cockroach allatostatin (Dip-AST). Fractions that co-eluted with cockroach allatostatins were immunoreactive, and at least two peaks of immunoreactivity were detected. Material from each peak at 10 nM Dip-AST equivalents inhibited juvenile hormone biosynthesis in vitro by corpora allata of 2-day virgin D. punctata cockroaches; 1 nM was less effective, and non-immunoreactive fractions failed to inhibit juvenile hormone biosynthesis. Both crude and Sep-Pak (Waters) purified extracts of brains of earwigs containing 1 nM Dip-AST equivalents failed to suppress hindgut contractions in vitro of 2-day earwigs and of brooding female earwigs. In contrast, 1 nM cockroach allostatin 1 (Dip-AST 7) reversibly inhibited hindgut contractions in vitro. These results suggested the presence of another brain factor, such as proctolin, that counteracts the inhibitory effects of Dip-AST. In support of this hypothesis, proctolin stimulated hindgut contractions in vitro at 1 nM; the effects of equal concentrations of allatostatin and proctolin varied with the stage of the female. Furthermore, HPLC-separated fractions that co-eluted with cockroach allatostatin and were immunoreactive with antibodies to Dip-AST suppressed hindgut contractions in vitro of 2-day female earwigs. Finally, crude brain extracts of earwigs suppressed earwig juvenile hormone biosynthesis in vitro in glands of low, but not in glands of high, activity. Thus, earwig brain extract after HPLC separation has Dip-AST-like material that inhibits cockroach corpora allata and suppresses earwig hindgut contractions. Sep-Pak-extracted earwig brain material, however, does not inhibit earwig gut contraction. Although synthetic Dip-AST 7 does not inhibit juvenile hormone synthesis by earwig corpora allata, there is heat-stable material in earwig brain extract that does have this action.     

Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry as a useful tool for the rapid identification of wild flea vectors preserved in alcohol

Flea identification is a significant issue because some species are considered as important vectors of several human pathogens that have emerged or re‐emerged recently, such as Bartonella henselae (Rhizobiales: Bartonellaceae) and Rickettsia felis (Rickettsiales: Rickettsiaceae). Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) has been evaluated in recent years for the identification of multicellular organisms, including arthropods. A preliminary study corroborated the usefulness of this technique for the rapid identification of fleas, creating a preliminary database containing the spectra of five species of flea. However, longterm flea preservation in ethanol did not appear to be an adequate method of storage in the context of specimen identification by MALDI‐TOF MS profiling. The goal of the present work was to assess the performance of MALDI‐TOF MS in the identification of seven flea species [Ctenocephalides felis (Siphonaptera: Pulicidae), Ctenocephalides canis, Pulex irritans (Siphonaptera: Pulicidae), Archaeopsylla erinacei (Siphonaptera: Pulicidae), Leptopsylla taschenbergi (Siphonaptera: Ceratophyllidae), Stenoponia tripectinata (Siphonaptera: Stenoponiidae) and Nosopsyllus fasciatus (Siphonaptera: Ceratophyllidae)] collected in the field and stored in ethanol for different periods of time. The results confirmed that MALDI‐TOF MS can be used for the identification of wild fleas stored in ethanol. Furthermore, this technique was able to discriminate not only different flea genera, but also the two congeneric species C. felis and C. canis.     

Review of established and innovative detection methods for carbapenemase‐producing Gram‐negative bacteria

The minimal antibiotic options for carbapenemase‐producing Gram‐negative bacteria necessitate their rapid detection. A literature review of a variety of phenotypic and genotypic methods is presented. Advances in culture methods and screening media are still subject to long incubation hours. Biochemical methods have shorter turnaround times and higher sensitivities and specificities, but cannot differentiate between various types and variants. Spectrophotometric methods are cheap and efficient, but are uncommon in many clinical settings, while the MALDI‐TOF MS is promising for species identification, typing and resistance gene determination. Although next generation sequencing (NGS) technologies provide a better platform to detect, type and characterize carbapenem‐resistant bacteria, the different NGS platforms, the large computer memories and space needed to process and store genomic data and the nonuniformity in data analysis platforms are still a challenge. The sensitivities, specificities and turnaround times recorded in the various studies reviewed favours the use of the biochemical tests (Carba NP or Rapid Carb screen tests) for the detection of putative carbapenemase‐producing isolates. MALDI‐TOF MS and/or molecular methods like microarray, loop‐mediated isothermal amplification and real‐time multiplex PCR assays could be used for further characterization in a reference laboratory. NGS may be used for advanced epidemiological and molecular studies.     

Detection of Biomarkers of Pathogenic Naegleria fowleri Through Mass Spectrometry and Proteomics

Emerging methods based on mass spectrometry (MS) can be used in the rapid identification of microorganisms. Thus far, these practical and rapidly evolving methods have mainly been applied to characterize prokaryotes. We applied matrix‐assisted laser‐desorption‐ionization‐time‐of‐flight mass spectrometry MALDI‐TOF MS in the analysis of whole cells of 18 N. fowleri isolates belonging to three genotypes. Fourteen originated from the cerebrospinal fluid or brain tissue of primary amoebic meningoencephalitis patients and four originated from water samples of hot springs, rivers, lakes or municipal water supplies. Whole Naegleria trophozoites grown in axenic cultures were washed and mixed with MALDI matrix. Mass spectra were acquired with a 4700 TOF‐TOF instrument. MALDI‐TOF MS yielded consistent patterns for all isolates examined. Using a combination of novel data processing methods for visual peak comparison, statistical analysis and proteomics database searching we were able to detect several biomarkers that can differentiate all species and isolates studied, along with common biomarkers for all N. fowleri isolates. Naegleria fowleri could be easily separated from other species within the genus Naegleria. A number of peaks detected were tentatively identified. MALDI‐TOF MS fingerprinting is a rapid, reproducible, high‐throughput alternative method for identifying Naegleria isolates. This method has potential for studying eukaryotic agents.     

Evidence from multiple gene sequences indicates that termites evolved from wood-feeding cockroaches

Despite more than half a century of research, the evolutionary origin of termites remains unresolved [1] [2] [3]. A clear picture of termite ancestry is crucial for understanding how these insects evolved eusociality, particularly because they lack the haplodiploid genetic system associated with eusocial evolution in bees, ants, wasps and thrips [4] [5]. Termites, together with cockroaches and praying mantids, constitute the order Dictyoptera, which has been the focus of numerous conflicting phylogenetic studies in recent decades [6] [7] [8] [9] [10] [11] [12]. With the aim of settling the debate over the sister-group of termites, we have determined the sequences of genes encoding 18S ribosomal RNA, mitochondrial cytochrome oxidase subunit II (COII) and endogenous endo-beta-1, 4-glucanase (EG) from a diverse range of dictyopterans. Maximum parsimony and likelihood analyses of these sequences revealed strong support for a clade consisting of termites and subsocial, wood-feeding cockroaches of the genus Cryptocercus. This clade is nested within a larger cockroach clade, implicating wood-feeding cockroaches as an evolutionary intermediate between primitive non-social taxa and eusocial termites.