A Molecular Phylogenetic Investigation of Bakuella, Anteholosticha, and Caudiholosticha (Protista, Ciliophora, Hypotrichia) Based on Three‐Gene Sequences

Abstract

Traditionally classifications of the Urostyloida have been mainly based on morphology and morphogenesis. Recent molecular phylogenetic analyses have been largely based on single-gene data for a limited number of taxa. Consequently, incongruence has arisen between the morphological/morphogenetic and the molecular data. In this study, the three phylogenetic markers (SSU rDNA, ITS1-5.8S-ITS2 region, and LSU-rDNA) of three urostyloid genera represented by four species (Bakuella granulifera, Anteholosticha monilata, Caudiholosticha sylvatica, and C. tetracirra) were sequenced to investigate their phylogeny. The results show that: (1) all three genera should be regarded as the members of the order Urostyloida within the subclass Hypotrichia, as indicated by morphological characters; (2) phylogenetic analyses and sequence similarities both indicate that neither Anteholosticha nor Caudiholosticha are monophyletic and the systematic assignment of both genera awaits further evaluation; and (3) Bakuella has a closer relationship with Urostyla than with bakuellids (e.g. Apobakuella and Metaurostylopsis), suggesting Bakuella may belong to the family Urostylidae rather than the family Bakuellidae.

Redescription of two little-known urostyloid ciliates, Anteholosticha randani (Grolière, 1975) Berger, 2003 and A. antecirrata Berger, 2006 (Ciliophora, Urostylida)

“…Therefore we here present only the ML tree with bootstraps and posterior probabilities. As shown in previous studies (Huang et al 2014;Lv et al 2015;Zhao et al 2015), the urostyloids are non-monophyletic whereas a "Core Urostylids" group is strongly supported (94% ML, 1.00 BI) and composed of two major sub-clades. Within the first sub-clade (46% ML, 0.97 BI), Anteholosticha antecirrata clusters with Urostyla grandis and Bakuella granulifera with maximum support (100% ML, 1.00 BI), and then forms a well-supported sister relationship to a large group containing Bakuella, Apobakuella, Neobakuella, Diaxonella and three congeners of Anteholosticha (i.e.…”

“…anterior end of the left marginal row curved rightwards, the bipartite adoral zone and the buccal cirrus distinctly ahead of the paroral). Berger (2003Berger ( , 2006 noted that Anteholosticha is non-monophyletic and this was subsequently supported by molecular data (Fan et al 2014b;Lv et al 2015;Zhao et al 2015). Based upon a phylogenetic analysis of three genes, Huang et al (2014) transferred three species of Anteholosticha, namely A.…”

Morphology and SSU rDNA sequence analysis of two hypotrichous ciliates (Protozoa, Ciliophora, Hypotrichia) including the new species Metaurostylopsis parastruederkypkeae n. sp.

“…and Sequencing Genomic DNA was extracted from cleaned cells using the DNeasy Tissue Kit (Qiagen) according to Lv et al (2015). TaKaRa ExTaq DNA polymerase (Takara Biotechnology Co., Ltd., Dalian, China) and the universal primers Euk A and Euk B (Medlin et al, 1988) were used to amplify the SSU rDNA.…”

“…Cycling parameters were as follows: One cycle of initial denaturation for 5 min, followed by 18 cycles of amplification (94℃, 1 min; 66-49 ℃ touch down, 40 s; 72℃, 2 min) and another 18 cycles of amplification (94℃, 30 s; 48℃, 40 s; 72℃, 2 min), with a final extension of 72℃ for 7 min. Cloning was performed according to Lv et al (2015) using the pEASY-T1 Cloning Kit (Transgen Biotech, China). Recombinant plasmids from six clones each species were sequenced bidirectionally (GENEWIZ incorporated company, Beijing, China).…”

“…According to this detailed revision, Family Urostyloidea includes about 34 valid genera and 154 valid species. In recent years, several new species were added to this family, which suggested that the diversity of this family of ciliates was under-estimated (e.g., Chen et al, 2011Chen et al, , 2013Fan et al, 2015Fan et al, , 2016Foissner and Stoeck, 2008;Hu et al, 2015;Jo et al, 2015;Jung et al, 2011Jung et al, , 2015Luo et al, 2015;Lv et al, 2015;Paiva et al, 2016;Shao et al, 2008a, b;Wang et al, 2011).…”