Journal: IMA Fungus

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Abbreviation

Publisher

International Mycological Association

Journal Volumes

ISSN

2210-6340
2210-6359

Description

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Publications 1 - 4 of 4
  • Leal-Dutra, Caio Ambrosio; Yuen, Lok Man; Guedes, Bruno Augusto Maciel; et al. (2023)
    IMA Fungus
    Leafcutter ants farm a fungal cultivar (Leucoagaricus gongylophorus) that converts inedible vegetation into food that sustains colonies with up to millions of workers. Analogous to edible fruits of crops domesticated by humans, L. gongylophorus has evolved specialized nutritional rewards—swollen hyphal cells called gongylidia that package metabolites and are consumed by ant farmers. Yet, little is known about how gongylidia form, and thus how fungal physiology and ant provisioning collectively govern farming performance. We explored the process of gongylidium formation using advanced microscopy to image the cultivar at scales of nanometers, and both in vitro experiments and in silico analyses to examine the mechanisms of gongylidia formation when isolated from ant farmers. We first used transmission electron, fluorescence, and confocal microscopy imaging to see inside hyphal cells. This imaging showed that the cultivar uses a process called autophagy to recycle its own cellular material (e.g. cytosol, mitochondria) and then shuttles the resulting metabolites into a vacuole whose continual expansion displaces other organelles and causes the gongylidium cell’s bulging bulb-like appearance. We next used scanning electron microscopy and light microscopy to link this intracellular rearrangement to the external branching patterns of gongylidium cells as they clump together into edible bundles called staphyla. We next confirmed that autophagy plays a critical role in gongylidium formation both: (1) in vitro as gongylidium suppression occurred when isolated fungal cultures were grown on media with autophagy inhibitors, and (2) in silico as differential transcript expression (RNA-seq) analyses showed upregulation of multiple autophagy gene isoforms in gongylidia relative to undifferentiated hyphae. While autophagy is a ubiquitous and often highly derived process across the tree of life, our study reveals a new role for autophagy as a mechanism of functional integration between ant farmers and their fungal crop, and potentially as a signifier of higher-level homeostasis between uniquely life-time committed ectosymbionts.
  • Aime, M.C.; Castlebury, Lisa A.; Abbasi, Mehrdad; et al. (2018)
    IMA Fungus
    With the change to one scientific name for pleomorphic fungi, generic names typified by sexual and asexual morphs have been evaluated to recommend which name to use when two names represent the same genus and thus compete for use. In this paper, generic names in Pucciniomycotina and Ustilaginomycotina are evaluated based on their type species to determine which names are synonyms. Twenty-one sets of sexually and asexually typified names in Pucciniomycotina and eight sets in Ustilaginomycotina were determined to be congeneric and compete for use. Recommendations are made as to which generic name to use. In most cases the principle of priority is followed. However, eight generic names in the Pucciniomycotina, and none in Ustilaginomycotina, are recommended for protection: Classicula over Naiadella, Gymnosporangium over Roestelia, Helicobasidium over Thanatophytum and Tuberculina, Melampsorella over Peridermium, Milesina over Milesia, Phragmidium over Aregma, Sporobolomyces over Blastoderma and Rhodomyces, and Uromyces over Uredo. In addition, eight new combinations are made: Blastospora juruensis, B. subneurophyla, Cronartium bethelii, C. kurilense, C. sahoanum, C. yamabense, Milesina polypodii, and Prospodium crusculum combs. nov.
  • Baral, Hans-Otto; Queloz, Valentin K.; Hosoya, Tsuyoshi S. (2014)
    IMA Fungus
    Under the rules for the naming of fungi with pleomorphic life-cycles adopted in July 2011, the nomenclaturally correct name for the fungus causing the current ash dieback in Europe is determined to be Hymenoscyphus fraxineus, with the basionym Chalara fraxinea, and Hymenoscyphus pseudoalbidus as a taxonomic synonym of H. fraxineus.
  • Zamora, Juan C.; Svensson, Måns; Kirschner, Roland; et al. (2018)
    IMA Fungus
    Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
Publications 1 - 4 of 4