title: Microbial eukaryote communities exhibit robust biogeographical patterns along a gradient of Patagonian and Antarctic lakes.
abstract: Microbial eukaryotes play important roles in aquatic ecosystem functioning. Unravelling their distribution patterns and biogeography provides important baseline information to infer the underlying mechanisms that regulate the biodiversity and complexity of ecosystems. We studied the distribution patterns and factors driving diversity gradients in microeukaryote communities (total, abundant, uncommon and rare community composition) along a latitudinal gradient of lakes distributed from Argentinean Patagonia to Maritime Antarctica using both denaturing gradient gel electrophoresis (DGGE) and high-throughput sequencing (Illumina HiSeq). DGGE and abundant Illumina operational taxonomic units (OTUs) showed both decreasing richness with latitude and significant differences between Patagonian and Antarctic lakes communities. In contrast, total richness did not change significantly across the latitudinal gradient, although evenness and diversity indices were significantly higher in Patagonian lakes. Beta-diversity was characterized by a high species turnover, influenced by both environmental and geographical descriptors, although this pattern faded in the rare community. Our results suggest the co-existence of a 'core biosphere' containing reduced number of abundant/dominant OTUs on which classical ecological rules apply, together with a much larger seedbank of rare OTUs driven by stochastic and reduced dispersal processes. These findings shed new light on the biogeographical patterns and forces structuring inland microeukaryote composition across broad spatial scales.
authors.affiliation: Centro de Investigaciones y transferencia del Noroeste de la Provincia de Buenos Aires, CONICET, UNNOBA, Junín, 6000, Argentina.
authors.forename: M Romina
authors.initials: MR
authors.lastname: Schiaffino
authors.affiliation: Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel, CH-2000, Switzerland.
authors.forename: Enrique
authors.initials: E
authors.lastname: Lara
authors.affiliation: Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel, CH-2000, Switzerland.|Laboratorio de Ecología Evolutiva y Filoinformática, Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Barrio Universitario s/n, Concepción, Chile.|Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Sede Concepción, Chacabuco 539, Concepción, Chile.
authors.forename: Leonardo D
authors.initials: LD
authors.lastname: Fernández
authors.affiliation: Institut de Ciències del Mar, CSIC, Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Balagué
authors.affiliation: Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel, CH-2000, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Singer
authors.affiliation: Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel, CH-2000, Switzerland.
authors.forename: Christophe C W
authors.initials: CC
authors.lastname: Seppey
authors.affiliation: Institut de Ciències del Mar, CSIC, Passeig Marítim de la Barceloneta 37-49, Barcelona, Catalonia, 08003, Spain.
authors.forename: Ramon
authors.initials: R
authors.lastname: Massana
authors.affiliation: Departamento de Ecología, Genética y Evolución, IEGEBA (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, C1428EHA, Argentina.
authors.forename: Irina
authors.initials: I
authors.lastname: Izaguirre
mesh_terms: D000864:Antarctic Regions; D044822:Biodiversity; D058645:Denaturing Gradient Gel Electrophoresis; D056890:Eukaryota / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005843:Geography; D060106:Lakes / Q000737:chemistry / Q000469:parasitology*