Phylogeny of the mycoparasite Escovopsis associated with higher attine ants

Abstract

Leaf-cutting ants (genera Atta and Acromyrmex) in the tribe Attini are well-known for their ability to cultivate fungi for food. Filamentous fungi in the genus Escovopsis are specialized parasites of the ant fungal cultivar. Although several studies focused on the parasitism, little is known about the genetic diversity of the parasite. Using a collection of 49 Escovopsis strains derived from higher attine ants collected in several Brazilian biomes, we sequenced the tef1-alfa gene marker from all strains and reconstructed a draft phylogeny of the parasite. Preliminary results showed high genetic diversity in the genus with several clades comprising putative new phylogenetic species. Here, we aim to carry out a robust phylogenetic analysis with our dataset using powerful algorithms (Bayesian, maximum-likelihood and parsimony analyses). Such analyses are paramount to support the results obtained so far and will be carried out at the Section of Integrative Biology (University of Texas at Austin - UT); a center that harbors specialists on molecular systematics. In addition, we aim to expand our phylogeny by adding reference Escovopsis strains derived from higher attine ants. These additional Escovopsis strains are cryopreserved at UT and were collected in different countries by Dr. Ulrich G. Mueller. Morphological characters of the strains will be examined and the tef1-alfa marker will be sequenced in order to incorporate such reference strains into the existent phylogeny. By coupling robust phylogenetic analyses with additional reference strains, we hope to shed light on the evolutionary history of this important parasite involved on the attine ant-microbe symbiosis. (AU)