title: Mycamoeba gemmipara nov. gen., nov. sp., the First Cultured Member of the Environmental Dermamoebidae Clade LKM74 and its Unusual Life Cycle.
abstract: Since the first environmental DNA surveys, entire groups of sequences called "environmental clades" did not have any cultured representative. LKM74 is an amoebozoan clade affiliated to Dermamoebidae, whose presence is pervasively reported in soil and freshwater. We obtained an isolate from soil that we assigned to LKM74 by molecular phylogeny, close related to freshwater clones. We described Mycamoeba gemmipara based on observations made with light- and transmission electron microscopy. It is an extremely small amoeba with typical lingulate shape. Unlike other Dermamoebidae, it lacked ornamentation on its cell membrane, and condensed chromatin formed characteristic patterns in the nucleus. M. gemmipara displayed a unique life cycle: trophozoites formed walled coccoid stages which grew through successive buddings and developed into branched structures holding cysts. These structures, measuring hundreds of micrometres, are built as the exclusive product of osmotrophic feeding. To demonstrate that M. gemmipara is a genuine soil inhabitant, we screened its presence in an environmental soil DNA diversity survey performed on an experimental setup where pig cadavers were left to decompose in soils to follow changes in eukaryotic communities. Mycamoeba gemmipara was present in all samples, although related reads were uncommon underneath the cadaver.
authors.affiliation: Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Emile Argand 11, Neuchâtel, 2000, Switzerland.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Blandenier
authors.affiliation: Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Emile Argand 11, Neuchâtel, 2000, Switzerland.
authors.forename: Christophe V W
authors.initials: CV
authors.lastname: Seppey
authors.affiliation: Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Emile Argand 11, Neuchâtel, 2000, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Singer
authors.affiliation: Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Emile Argand 11, Neuchâtel, 2000, Switzerland.
authors.forename: Michèle
authors.initials: M
authors.lastname: Vlimant
authors.affiliation: Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Emile Argand 11, Neuchâtel, 2000, Switzerland.
authors.forename: Anaële
authors.initials: A
authors.lastname: Simon
authors.affiliation: Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Emile Argand 11, Neuchâtel, 2000, Switzerland.
authors.forename: Clément
authors.initials: C
authors.lastname: Duckert
authors.affiliation: Laboratory of Soil Biodiversity, Institute of Biology, University of Neuchâtel, Emile Argand 11, Neuchâtel, 2000, Switzerland.
authors.forename: Enrique
authors.initials: E
authors.lastname: Lara
mesh_terms: D000656:Amoeba / Q000145:classification / Q000166:cytology; D056894:Amoebozoa / Q000145:classification* / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D000818:Animals; D044822:Biodiversity; D002102:Cadaver; D002462:Cell Membrane; D016054:DNA, Protozoan / Q000235:genetics; D004777:Environment; D005618:Fresh Water / Q000469:parasitology; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D008018:Life Cycle Stages; D046529:Microscopy, Electron, Transmission; D015388:Organelles / Q000648:ultrastructure; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012987:Soil / Q000469:parasitology; D013552:Swine / Q000469:parasitology; D013557:Switzerland; D053058:Trophozoites / Q000254:growth & development
chemical_list: D016054:DNA, Protozoan; D012337:RNA, Ribosomal, 18S; D012987:Soil
keywords: Budding; Discosea; Longamoebia; eukaryotic diversity; fungus; high throughput sequencing; ribosomal genes; serial dilution; yeast