First record of Harpellales, Orphellales (Kickxellomycotina) and Amoebidiales (Mesomycetozoea) from Bulgaria, including a new species of Glotzia

This paper presents the results obtained from a short survey performed in Bulgaria, southeast Europe, where the trichomycetes (sensu lato), an ecological group of arthropod gut endosymbionts, were previously completely unknown. The present study initiates the comprehension of these cryptic organisms, members of the Kickxellomycotina (Harpellales, Orphellales) and the Mesomycetozoea (Amoebidiales), in this Balkan country. Eighteen new geographic records for Bulgaria are reported, including 10 species of Harpellales, three species of Orphellales and five species of Amoebidiales. Within the Harpellales, the species Glotziabalkanensissp. nov. is described. This new species is most related to the rare species G.centroptili Gauthier ex Manier & Lichtw. and G.stenospora White & Lichtw., but is differentiated by spore and thallial characteristics. Photographs are provided and biogeographic implications of these records are discussed.

Genome-Wide Survey of Gut Fungi (Harpellales) Reveals the First Horizontally Transferred Ubiquitin Gene from a Mosquito Host

Harpellales, an early-diverging fungal lineage, is associated with the digestive tracts of aquatic arthropod hosts. Concurrent with the production and annotation of the first four Harpellales genomes, we discovered that Zancudomyces culisetae, one of the most widely distributed Harpellales species, encodes an insect-like polyubiquitin chain. Ubiquitin and ubiquitin-like proteins are universally involved in protein degradation and regulation of immune response in eukaryotic organisms. Phylogenetic analyses inferred that this polyubiquitin variant has a mosquito origin. In addition, its amino acid composition, animal-like secondary structure, as well as the fungal nature of flanking genes all further support this as a horizontal gene transfer event. The single-copy polyubiquitin gene from Z. culisetae has lower GC ratio compared with homologs of insect taxa, which implies homogenization of the gene since its putatively ancient transfer. The acquired polyubiquitin gene may have served to improve important functions within Z. culisetae, by perhaps exploiting the insect hosts' ubiquitin-proteasome systems in the gut environment. Preliminary comparisons among the four Harpellales genomes highlight the reduced genome size of Z. culisetae, which corroborates its distinguishable symbiotic lifestyle. This is the first record of a horizontally transferred ubiquitin gene from disease-bearing insects to the gut-dwelling fungal endobiont and should invite further exploration in an evolutionary context.

Consolidating the legacy of J.-F. Manier: new species and records of trichomycetes from France

New data about trichomycetes (arthropod-gut endosymbionts) from southern France is documented, including the description of two Harpellales, Legeriosimilis cebennensis from mayfly nymphs (Heptageniidae) and Smittium manierei from Chironomidae larvae. New geographical records from France are provided, including Bojamyces transfuga, Genistellospora homothallica, Lancisporomyces vernalis, Legeriomyces rarus, Orphella catalaunica, O. helicospora, Stachylina pedifer, Smittium hecatei, S. pseudodimorphum and Tectimyces leptophlebiidarum. Most of these records include species with a Mediterranean distribution, reported before from neighboring countries, and a few others are subcosmopolitan.

Dipteran-associated Harpellales from lowland and submontane tropical rain forests of Veracruz (Mexico)

We report on the species of Harpellales found in dipteran hosts during two surveys (32 field d) in the state of Veracruz, Mexico. One new morphospecies, Genistellospora dorsicaudata, is described with particular attention to the position of the terminal cell associated with fully developed fertile thalli bearing sexual spores. We emend the description of G. guanacastensis to include morphometrics on the zygospores, based on discovery of the sexual spores for that species in our collections. Thirteen other previously described species, which are new for Mexico, include G. homothallica, Pennella montana, Simuliomyces microsporus, Smittium aciculare, S. brasiliense (in a new host type), S. culisetae, S. dipterorum, S. microsporum, S. simulii and the unbranched species Harpella melusinae, H. tica, Stachylina grandispora and S. paucispora. Some species have been described but not named, specifically one each of Harpella, Pennella and Smittium. All taxa are identified morphologically, illustrated and additional details on their ecology are provided.