Аннотация:Recent molecular phylogenetic studies revealed the extraordinary diversity of
single-celled eukaryotes. However, the proper assessment of this diversity and
accurate reconstruction of the eukaryote phylogeny are still impeded by the lack
of molecular data for some major groups of easily identifiable and cultivable
protists. Among them, amoeboid eukaryotes have been notably absent from
molecular phylogenies, in spite of their diversity, complexity and abundance. To
partly fill this phylogenetic gap, we present here the first multigene (smallsubunit
ribosomal RNA and/or actin) sequence data for the three main groups
of Heliozoa (Actinophryida, Centrohelida, Desmothoracida), the heliozoanlike
Sticholonche, and the radiolarian group Polycystinea. Phylogenetic analyses
of our sequences demonstrate the polyphyly of heliozoans, which branch either
as an independent eukaryotic lineage (Centrohelida), or within stramenopiles
(Actinophryida), or among cercozoans (Desmothoracida), in broad agreement
with previous ultrastructure-based studies. Our data also provide the first
multigene evidence for the existence of the Rhizaria, a new supergroup of mainly amoeboid eukaryotes which includes desmothoracid heliozoans, all radiolarians,
Sticholonche, foraminiferans, as well as various filose and reticulose amoebae
and some flagellates.