Browsing by Author "Meirelles, Lucas A."

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    New Light on the Systematics of Fungi Associated with Attine Ant Gardens and the Description ofﾠEscovopsis kreiseliiﾠsp. nov.
    (Public Library of Science, 2015) Meirelles, Lucas A.; Montoya, Quimi V.; Solomon, Scott E.; Rodrigues, André; Biosciences
    Since the formal description of fungi in the genus Escovopsis in 1990, only a few studies have focused on the systematics of this group. For more than two decades, only two Escovopsis species were described; however, in 2013, three additional Escovopsis species were formally described along with the genus Escovopsioides, both found exclusively in attine ant gardens. During a survey for Escovopsis species in gardens of the lower attine ant Mycetophylax morschi in Brazil, we found four strains belonging to the pink-colored Escovopsis clade. Careful examination of these strains revealed significant morphological differences when compared to previously described species of Escovopsis and Escovopsioides. Based on the type of conidiogenesis (sympodial), as well as morphology of conidiogenous cells (percurrent), non-vesiculated conidiophores, and DNA sequences, we describe the four new strains as a new species, Escovopsis kreiselii sp. nov. Phylogenetic analyses using three nuclear markers (Large subunit RNA; translation elongation factor 1-alpha; and internal transcribed spacer) from the new strains as well as available sequences in public databases confirmed that all known fungi infecting attine ant gardens comprise a monophyletic group within the Hypocreaceae family, with very diverse morphological characteristics. Specifically, Escovopsis kreiselii is likely associated with gardens of lower-attine ants and its pathogenicity remains uncertain.
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    Shared Escovopsis parasites between leaf-cutting and non-leaf-cutting ants in the higher attine fungus-growing ant symbiosis
    (Royal Society, 2015) Meirelles, Lucas A.; Solomon, Scott E.; Bacci, Mauricio; Wright, April M.; Mueller, Ulrich G.; Rodrigues, André; Biosciences
    Fungus-gardening (attine) ants grow fungus for food in protected gardens, which contain beneficial, auxiliary microbes, but also microbes harmful to gardens. Among these potentially pathogenic microorganisms, the most consistently isolated are fungi in the genus Escovopsis, which are thought to co-evolve with ants and their cultivar in a tripartite model. To test clade-to-clade correspondence between Escovopsis and ants in the higher attine symbiosis (including leaf-cutting and non-leaf-cutting ants), we amassed a geographically comprehensive collection of Escovopsis from Mexico to southern Brazil, and reconstructed the corresponding Escovopsis phylogeny. Contrary to previous analyses reporting phylogenetic divergence between Escovopsis from leafcutters and Trachymyrmex ants (non-leafcutter), we found no evidence for such specialization; rather, gardens from leafcutters and non-leafcutters genera can sometimes be infected by closely related strains of Escovopsis, suggesting switches at higher phylogenetic levels than previously reported within the higher attine symbiosis. Analyses identified rare Escovopsis strains that might represent biogeographically restricted endemic species. Phylogenetic patterns correspond to morphological variation of vesicle type (hyphal structures supporting spore-bearing cells), separating Escovopsis with phylogenetically derived cylindrical vesicles from ancestral Escovopsis with globose vesicles. The new phylogenetic insights provide an improved basis for future taxonomic and ecological studies of Escovopsis.