Análise da composição química da cutícula e do veneno de duas vespas sociais (Hymenoptera: vespidae) POR CG-EM e MALDI-TOF/TOF

Abstract

The cohesion of social insect colonies is maintained by interactions between their members mediated by chemical compounds, especially those present on their cuticle. These compounds are called cuticular hydrocarbons and act primarily as a protective coating preventing water loss, however,also act as signals exchanged during interactions between nestmates. Thus, these compounds act as a chemical signature, and can even vary between individuals depending on the tasks they perform in their colonies. Social insects also produce other chemical compounds that contribute to colony maintenance by acting in prey capture and defense. Venoms produced by the sting apparatus that consist of biologically active amines (serotonin and histamine), proteins, peptides, lipids, enzymes (phospholipases, hyaluronidases and phosphatases) and allergens. In addition to volatile compounds that are basically alkanes, branched alkanes, alkenes and alcohols, which can also play an important role as signals exchanged during interactions between nestmates. Evolutionarily, these compounds have arisen to enable prey capture and later were used for repelling attacks on the colony. Our results assessed by gas chromatography coupled to mass spectrometry (GC/MS) show that both the chemical profile of the cuticle and the nonpolar portion of venom of the species Apoica pallens and Polistes versicolor vary qualitatively and quantitatively between cuticle and venom, with predominance in abundance and number of branched alkanes. In the cuticle, there is higher concentration (in content and number) of heavy compounds that might act as superficial pheromones. In the venom lighter compounds were the most abundant both in content and in number of compounds, suggesting that the venom, in these species, at least the nonpolar portion might be involved in signaling during interactions between nestmates. By proteomic analysis of the venom of A. pallens, 30 proteins were identified by MALDITOF/TOF (Matrix Assisted Laser Desorption/Ionization time-of-flight), which according to their respective functions were divided into 8 categories: allergenic, enzymatic, metabolic, structural, environmental response, active in DNA and RNA, proteoglycan and with unknown function. The identification of these compounds is a first step towards their study for applied pharmacological use.