Cuticular hydrocarbons of triatomines.

JUAREZ M.P.

Salvador de Bahia, Brasil

Workshop; Rhodnius Genome Workshop; 2007

Rhodnius Genome Consortium

The subfamily Triatominae (Hemiptera: Reduviidae) include more than 130 species of insects, vectors of the Chagas Disease. The major vectorial capacities are shown by Triatoma infestans in South America and by Rhodnius prolixus, distributed through Mexico to Brazil. Triatomins cuticular surface is covered by a thin layer of lipids, mainly hydrocarbons, wax esters, fatty alcohols, and fatty acids. Evidences will be shown on the major role of hydrocarbons in preventing a lethal desiccation, altering the absorption of chemicals and microorganism penetration, and participating in chemical communication events. Fatty acid synthases and fatty acyl-CoA elongases were first shown to provide very long chain precursors to cuticular hydrocarbons in T. infestans integument. Capillary gas chromatography (CGC) coupled to mass spectrometry (MS) analyses showed that cuticular hydrocarbons of Triatominae are a complex mixture of saturated straight and methyl-branched chains, from 18 to more than 43 carbon atoms. Odd-straight chain hydrocarbons, mostly from 27 to 33 carbons, and different isomers with one to four methyl groups inserted in carbon skeletons from 29 to 39 atoms, account for the major hydrocarbon components. The presence, absence, and relative quantities of triatomine cuticular hydrocarbons determine their chemical phenotype, examples will be shown on its utility for differentiating genera, species, populations and sexes.