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).