Parvularia atlantis gen. et sp. nov., a Nucleariid Filose Amoeba (Holomycota, Opisthokonta)
Résumé
The opisthokonts constitute a eukaryotic supergroup divided into two main clades: the holozoans, which include animals and their unicellular relatives, and the holomycotans, which include fungi, opisthosporidians and nucleariids. Nucleariids are phagotrophic filose amoebae that phenotypically resemble more their distant holozoan cousins than their holomycotan phylogenetic relatives. Despite their evolutionary interest, the diversity and internal phylogenetic relationships within the nucleariids remain poorly studied. Here we formally describe and characterize by molecular phylogeny and microscopy observations Parvularia atlantis gen. et sp. nov. (formerly Nuclearia sp. ATCC 50694), and compare its features with those of other nucleariid genera. Parvularia is an amoebal genus characterized by radiating knobbed and branching filopodia. It exhibits prominent vacuoles observable under light microscopy, a cyst-like stage, and completely lacks cilia. P. atlantis possesses one or two nuclei with a central nucleolus, and mitochondria with flat or discoid cristae. These morphological features, although typical of nucleariids, represent a combination of characters different to those of any other described Nuclearia species. Likewise, 18S rRNA-based phylogenetic analyses show that P. atlantis represents a distinct lineage within the nucleariids. Keywords Protist evolution; nucleariid amoeba; protist diversity; filosea; taxonomy; phylogeny FROM a taxonomic point of view, Opisthokonta is considered one of the largest eukaryotic supergroups (Adl et al. 2012). It is divided into two clades: the Holozoa, which contains animals and their unicellular relatives (Lang et al. 2002), and the Holomycota (Liu et al.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...