Microbial eukaryote communities exhibit robust biogeographical patterns along a gradient of Patagonian and Antarctic lakes

SCHIAFFINO, M. R.; LARA, E.; FERNANDEZ PARRA, L.; BALAGUÉ, V.; SINGER D; SEPPEY CCW; MASSANA, R.; IZAGUIRRE I.

ENVIRONMENTAL MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2017

1462-2912

Microbial eukaryotes play important roles in aquaticecosystem functioning. Unravelling their distributionpatterns and biogeography provides important baselineinformation to infer the underlying mechanismsthat regulate the biodiversity and complexity of ecosystems.We studied the distribution patterns andfactors driving diversity gradients in microeukaryotecommunities (total, abundant, uncommon and rarecommunity composition) along a latitudinal gradientof lakes distributed from Argentinean Patagonia toMaritime Antarctica using both denaturing gradientgel electrophoresis (DGGE) and high-throughputsequencing (Illumina HiSeq). DGGE and abundantIllumina operational taxonomic units (OTUs) showedboth decreasing richness with latitude and significantdifferences between Patagonian and Antarcticlakes communities. In contrast, total richness did notchange significantly across the latitudinal gradient,although evenness and diversity indices were significantlyhigher in Patagonian lakes. Beta-diversity wascharacterized by a high species turnover, influencedby 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 rulesapply, together with a much larger seedbank of rareOTUs driven by stochastic and reduced dispersalprocesses. These findings shed new light on the biogeographicalpatterns and forces structuring inlandmicroeukaryote composition across broad spatialscales.