Ontogenesis and Molecular Phylogeny of a New Marine Urostylid Ciliate, Anteholosticha petzi n. sp. (Ciliophora, Urostylida)

Abstract

A new urostylid ciliate, Anteholosticha petzi n. sp., isolated from the northern China seas, was studied using live observation and protargol impregnation. It differs from all the congeners mainly in the highly flexible and variable body shape, its red-brown to brick-red colour, and the possession of three types of cortical granules. Analysis of morphometric and molecular data confirm the validity of A. petzi as a distinct species. Anteholosticha petzi n. sp. is characterized as follows: by having 3 frontal, 1 buccal, 2 frontoterminal, 2 pretransverse, and 8-11 transverse cirri; a midventral row that comprises 10-16 cirral pairs and extends ca. 60% of cell length; and 3 bipolar dorsal kineties. Ontogenesis is similar to that in Anteholosticha warreni except for the formation of the oral primordium and is characterized by: (1) the parental adoral membranelles are completely renewed and the oral primordium is formed de novo; and (2) the anlagen for the frontal-ventral-transverse cirri are formed as primary primordia. The small subunit rRNA gene sequence of A. petzi n. sp. was also compared with that of its congeners with the sequence differences ranging from 0.39% to 8.62%. Phylogenetic trees based on the SSU rRNA gene sequence were constructed, indicating the nonmonophyly of the genus Anteholosticha, as supported by the approximately unbiased test.

Phylogenetic framework of the systematically confused Anteholosticha–Holosticha complex (Ciliophora, Hypotrichia) based on multigene analysis

“…The SSU-rDNA tree (Fig. 1) constructed in this work is consistent with those published in previous studies (Park et al, 2013;Shao et al, 2011;Xu et al, 2011) and shows that Holosticha has a close relationship with Psammomitra and that species assigned to the genus Anteholosticha are distributed among several clades within the core urostylids assemblage. Our multigene analyses also confirm the polyphyly of Anteholosticha with high support values, which strengthens the morphological hypothesis that the diagnosis of Anteholosticha is only a combination of plesiomorphies, lacking good synapomorphies (Berger, 2003).…”

“…To date, about 40 species have been assigned to Anteholosticha, and new species are still being characterized and classified into this genus (Fan et al, 2014a;Park et al, 2013). The morphological hypothesis that Anteholosticha is not a monophyletic genus has been constantly supported by small subunit ribosomal RNA (SSU-rRNA) gene phylogenies (e.g., Chen et al, 2010;Park et al, 2013;Shao et al, 2011;Xu et al, 2011). As a first separation of the speciose genus Anteholosticha, three species (A. scutellum, A. petzi, A. warreni) with a roughly U-shaped pattern of transverse cirri, were transferred to a new genus Arcuseries by Huang et al (2014).…”

Three-gene based phylogeny of the Urostyloidea (Protista, Ciliophora, Hypotricha), with notes on classification of some core taxa

“…Anteholosticha scutellum (Cohn, 1866) Berger, 2003, A. petzi Shao et al, 2011, and Anteholosticha sp. formed a fully supported clade near the base of the SSU-rDNA tree (Fig.…”

Variations and evolution of polyubiquitin genes from ciliates

“…Our aims were to analyze the organization and variability of the genes and the proteins among ciliate species and lineages, to explore the possibility of using ubiquitin for higher classification of ciliates, and to examine the evolutionary mode of polyubiquitin genes in ciliates. (Chen et al 2011;Shao et al 2011;Song et al 2009). …”