Phylogenetic patterns of ant-fungus associations indicate that farming strategies, not only a superior fungal cultivar, explain the ecological success of leafcutter ants

Autor(es)

Mueller, Ulrich G. ^[1] ; Kardish, Melissa R. ^{[1, 2]} ; Ishak, Heather D. ^{[1, 3]} ; Wright, April M. ^[4] ; Solomon, Scott E. ^{[5, 6]} ; Bruschi, Sofia M. ^{[1, 7]} ; Carlson, Alexis L. ^[1] ; Bacci, Jr., Mauricio ^[7]

Afiliação do(s) autor(es)

^[1] Univ Texas Austin, Dept Integrat Biol, Austin, TX 78712 - USA

^[2] Univ Calif Davis, Ctr Populat Biol, Davis, CA 95616 - USA

^[3] Stanford Univ, Dept Med, Stanford, CA 94305 - USA

^[4] Southeastern Louisiana Univ, Dept Biol Sci, Hammond, LA 70402 - USA

^[5] Rice Univ, Dept Ecol & Evolutionary Biol, Houston, TX - USA

^[6] Smithsonian Inst, Dept Entomol, NHB 169, Washington, DC 20560 - USA

^[7] Univ Estadual Paulista, Ctr Estudos Insetos Sociais, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Molecular Ecology; v. 27, n. 10, p. 2414-2434, MAY 2018.
• Citações Web of Science: 13

Resumo

To elucidate fungicultural specializations contributing to ecological dominance of leafcutter ants, we estimate the phylogeny of fungi cultivated by fungus-growing (attine) ants, including fungal cultivars from (i) the entire leafcutter range from southern South America to southern North America, (ii) all higher-attine ant lineages (leafcutting genera Atta, Acromyrmex; nonleafcutting genera Trachymyrmex, Sericomyrmex) and (iii) all lower-attine lineages. Higher-attine fungi form two clades, Clade-A fungi (Leucocoprinus gongylophorus, formerly Attamyces) previously thought to be cultivated only by leafcutter ants, and a sister clade, Clade-B fungi, previously thought to be cultivated only by Trachymyrmex and Sericomyrmex ants. Contradicting this traditional view, we find that (i) leafcutter ants are not specialized to cultivate only Clade-A fungi because some leafcutter species ranging across South America cultivate Clade-B fungi; (ii) Trachymyrmex ants are not specialized to cultivate only Clade-B fungi because some Trachymyrmex species cultivate Clade-A fungi and other Trachymyrmex species cultivate fungi known so far only from lower-attine ants; (iii) in some locations, single higher-attine ant species or closely related cryptic species cultivate both Clade-A and Clade-B fungi; and (iv) ant-fungus co-evolution among higher-attine mutualisms is therefore less specialized than previously thought. Sympatric leafcutter ants can be ecologically dominant when cultivating either Clade-A or Clade-B fungi, sustaining with either cultivar-type huge nests that command large foraging territories; conversely, sympatric Trachymyrmex ants cultivating either Clade-A or Clade-B fungi can be locally abundant without achieving the ecological dominance of leafcutter ants. Ecological dominance of leafcutter ants therefore does not depend primarily on specialized fungiculture of L. gongylophorus (Clade-A), but must derive from ant-fungus synergisms and unique ant adaptations. (AU)

• Processo FAPESP: 14/25507-3 - Processamento de substratos por formigas Attini: dinâmica e cooperação metabólica com micro-organismos
• Beneficiário: Mauricio Bacci Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 03/08112-0 - Evolucao dos fungos simbiontes de attines (hymenoptera: formicidae).
• Beneficiário: Mauricio Bacci Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular