The cuticle is a biological composite material consisting principally of N-acetylglucosamine polymer embedded in cuticular proteins (CPs). CPs have been studied and characterized by mass spectrometry in several cuticular structures and in many arthropods. Such analyses were carried out by protein extraction using SDS followed by electrophoresis, allowing detection and identification of numerous CPs. To build a repertoire of cuticular structures from Bombyx mori, Apis mellifera and Anopheles gambiae the use of SDS and electrophoresis was avoided. Using the combination of hexafluoroisopropanol and of a surfactant compatible with MS, a high number of CPs was identified in An. gambiae wings, legs and antennae, and in the thoracic integument cuticle of Ap. mellifera pupae. The exoskeleton analysis of B. mori larvae allowed to identify 85 CPs from a single larva. Finally, the novel proteomics approach was tested on cuticles left behind after the molt from the fourth instar of Acyrthosiphon pisum. Analysis of these cast cuticles allowed to identify 100 Ac. pisum CPs as authentic cuticle constituents. These correspond to 68% of the total putative CPs previously annotated for this pea aphid. While this paper analyzes only the recovered cuticular proteins, peptides from many other proteins were also detected.

Aphids are phloem-feeding insects known as major pests in agriculture that are able to transmit hundreds of plant viruses. The majority of these viruses, classified as noncirculative, are retained and transported on the inner surface of the cuticle of the needle-like mouthparts while the aphids move from plant to plant. Identification of receptors of viruses within insect vectors is a key challenge because they are promising targets for alternative control strategies. The acrostyle, an organ discovered earlier within the common food/salivary canal at the tip of aphid maxillary stylets, displays proteins at the cuticle–fluid interface, some of which are receptors of noncirculative viruses. To assess the presence of stylet- and acrostyle-specific proteins and identify putative receptors, we have developed a comprehensive comparative analysis of the proteomes of four cuticular anatomical structures of the pea aphid, stylets, antennae, legs, and wings. In addition, we performed systematic immunolabeling detection of the cuticular proteins identified by mass spectrometry in dissected stylets. We thereby establish the first proteome of stylets of an insect and determine the minimal repertoire of the cuticular proteins composing the acrostyle. Most importantly, we propose a short list of plant virus receptor candidates, among which RR-1 proteins are remarkably predominant. The data are available via ProteomeXchange (PXD016517).

Honey bees play a critical role in the maintenance of plant biodiversity and sustainability of food webs. In the past few decades, bees have been subjected to biotic and abiotic threats causing various colony disorders. Therefore, monitoring solutions to help beekeepers to improve bee health are necessary. Matrix‐assisted laser desorption ionization–mass spectrometry (MALDI–MS) profiling has emerged within this decade as a powerful tool to identify in routine micro‐organisms and is currently used in real‐time clinical diagnosis. MALDI BeeTyping is developed to monitor significant hemolymph molecular changes in honey bees upon infection with a series of entomopathogenic Gram‐positive and ‐negative bacteria. A Serratia marcescens strain isolated from one naturally infected honey bee collected from the field is also considered. A series of hemolymph molecular mass fingerprints is individually recorded and to the authors' knowledge, the first computational model harboring a predictive score of 97.92% and made of nine molecular signatures that discriminate and classify the honey bees’ systemic response to the bacteria is built. Hence, the model is challenged by classifying a training set of hemolymphs and an overall recognition of 91.93% is obtained. Through this work, a novel, time and cost saving high‐throughput strategy that addresses honey bee health on an individual scale is introduced.

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ResumenSe presenta un modelo lagrangeano de dinámica de floculas que considera partículas minerales finas en suspensión. El modelo describe en forma discreta el movimiento turbulento de las partículas, su sedimentación dependiendo del tamaño de grano de los agregados, así como los procesos de interacción que conllevan a la agregación y disgregación de las floculas. Con base en múltiples experimentos numéricos se persigue establecer una parametrización de la floculación dependiendo de la concentración de floculas suspendidas y la energía cinética de turbulencia del fluido. Con partículas elementales de 10 pm, estrés de Reynolds de 2.34 N m"2 y concentraciones entre 1 y 550 mg l"1 se obtiene un espectro gausiano de distribución del tamaño de floculas. Aumentando el estrés, el espectro tiende a disminuir hasta que las floculas desaparecen. En adición, se logra describir en el modelo el concepto gráfico dado por Dyer sobre la floculación. En general, bajo los límites pre-establecidos del experimento, se obtiene una representación aceptable de la dinámica de floculas para las simulaciones en los modelos hidrodinámicos complejos. El uso de las parametrizaciones expuestas es sugerido en simulaciones de sedimentos cohesivos.

Among pollinator insects, bees undoubtedly account for the most important species. They play a critical role in boosting reproduction of wild and commercial plants and therefore contribute to the maintenance of plant biodiversity and sustainability of food webs. In the last few decades, domesticated and wild bees have been subjected to biotic and abiotic threats, alone or in combination, causing various health disorders. Therefore, monitoring solutions to improve bee health are increasingly necessary. MALDI mass spectrometry has emerged within this decade as a powerful technology to biotype micro-organisms. This method is currently and routinely used in clinical diagnosis where molecular mass fingerprints corresponding to major protein signatures are matched against databases for real-time identification. Based on this strategy, we developed MALDI BeeTyping as a proof of concept to monitor significant hemolymph molecular changes in honey bees upon infection with a series of entomopathogenic Gram-positive and -negative bacteria. A Serratia marcescens strain isolated from one “naturally” infected honey bee collected from the field was also considered. We performed a series of individually recorded hemolymph molecular mass fingerprints and built, to our knowledge, the first computational model made of nine molecular signatures with a predictive score of 97.92%. Hence, we challenged our model by classifying a training set of individual bees’ hemolymph and obtained overall recognition of 91.93%. Through this work, we aimed at introducing a novel, realistic, and time-saving high-throughput biotyping-like strategy that addresses honey bee health in infectious conditions and on an individual scale through direct “blood tests”.Significance StatementDomesticated and wild bees worldwide represent the most active and valuable pollinators that ensure plant biodiversity and the success of many crops. These pollinators and others are exposed to deleterious pathogens and environmental stressors. Despite efforts to better understand how these threats affect honey bee health status, solutions are still crucially needed to help beekeepers, scientists and stakeholders in obtaining either a prognosis, an early diagnosis or a diagnosis of the health status of the apiaries. In this study, we describe a new method to investigate honey bee health by a simple “blood test” using fingerprints of some peptides/proteins as health status signatures. By computer modelling, we automated the identification of infected bees with a predictive score of 97.92%.