Changes in the cuticular hydrocarbon profile associated with the molting cycle correlate with the hydrocarbon profile of the fungus cultivated by the ant Atta sexdens
Leaf-cutting ants live in obligate mutualism with a basidiomycete fungus that they use as a rearing site and food resource. Chemical analyses of the fungus gardens kept by these ants have revealed the presence of hydrocarbons that also occur in the epicuticle of the ants. However, whether it is the fungus or the ants which are the ultimate producers of these compounds is not yet clear. To shed light on the chemoecological aspects of the symbiotic relationship between ant and fungus, in the present study, we aimed to characterize the changes in the cuticular chemical profiles during larval-to-adult molting of Atta sexdens workers, which allowed us to investigate how these changes were correlated with the chemical profile of fungal cultivars. The results show that cuticular hydrocarbon profiles of ants were comprised of linear and branched alkanes that varied significantly, according to developmental stages, with several ant-specific hydrocarbons being identified as the most representative ones. The chemical profile of symbiotic fungus was predominantly comprised of linear alkanes, which also occurred in the cuticle of the ants. Chemical distances calculated with the chemical profiles of the analyzed groups revealed a great similarity between the hydrocarbon profile of symbiotic fungus and those of the ants, especially at the earliest stages of ants’ development, when mainly linear alkanes were identified. However, as individuals progressed through developmental stages, the chemical profiles increased in difference, due to the fact that several branched alkanes were found in great proportions in the cuticle of the ants. These findings suggest that the intimate relationship between brood and fungus might shape the hydrocarbon profile of both species, and the possible scenarios for the transference of these substances are discussed.
KeywordsCuticular hydrocarbons Molting cycle Atta sexdens Leucoagaricus gongylophorus
The authors thank two anonymous referees for helpful comments on the previous version of the manuscript. This work was supported by the National Council of Scientific and Technological Development (CNPq), and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, 2010/10027-5).
- Della Lucia TMC (ed) (1993) As Formigas Cortadeiras. Editora Folha de Viçosa, Viçosa, p 262Google Scholar
- Hunt JH, Napela CA (1994) Nourishment and evolution in insects societies. Westview Press, Boulder, p 449Google Scholar
- Ladygina N, Dedyukhina EG, Vainshtein MB (2006) A review on microbial synthesis of hydrocarbons. Process Biochem 1001–1014Google Scholar
- Lambardi D, Chegia B, Turilazzi S, Boomsma JJ (2004) Diet-induced aggression among colonies of the leafcutter ant Acromyrmex echinatior Forel (Hymenoptera Formicidae). Redia 21:219–221Google Scholar
- Richard FJ, Heftz A, Christides JP, Errard C (2004) Food influence on colonial recognition and chemical signature between nestmates in the fungus-growing ant Acromyrmex subterraneus subterraneus. J Chem Ecol 14:9–16Google Scholar
- Schneider MO (2004) Comportamento de cuidado com a prole na saúva-limão Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae). MSc Thesis, Universidade Estadual Paulista Júlio de Mesquita Filho, Rio Claro, Brasil, p 86Google Scholar
- Shaw JJ, Spakowicz DJ, Dalal RS, Davis JH, Lehr NA, Dunican BF, Orellana EA, Narváez-Trujillo A, Strobel SA (2015) Biosynthesis and genomic analysis of medium-chain hydrocarbon production by the endophytic fungal isolate Nigrograna mackinnonii E5202H. Appl Microbiol Biotechnol 99:3715–3728CrossRefPubMedPubMedCentralGoogle Scholar
- Siqueira CG, Bacci M, Pagnocca FC, Bueno OC, Hebling MJA (1998) Metabolism of plant polysaccharides by Leucoagaricus gongylophorus, the symbiotic fungus of leaf-cutting ant Atta sexdens L. Appl Environ Microbiol 64:4820–4822Google Scholar
- Vander Meer RK, Morel L (1998) Nestmate recognition in ants. In: Vander Meer RK, Breed M, Wintson M, Espelie KE (eds) Pheromone communication in social insects. Westview Press, Boulder, p 384Google Scholar