Multi-Gene Phylogeny of the Ciliate Genus Trachelostyla (Ciliophora, Hypotrichia), With Integrative Description of Two Species, Trachelostyla multinucleata Spec. nov. and T. pediculiformis (Cohn, 1866)

• Published in: Frontiers in microbiology 2022-02, Vol.12, p.775570-775570
• Main Authors: Zhang, Tengyue, Shao, Chen, Zhang, Tengteng, Song, Weibo, Vd'ačný, Peter, Al-Farraj, Saleh A, Wang, Yurui
• Format: Article
• Language: English
• Subjects: ciliated protists; integrative taxonomy; ITS2 secondary structure; Microbiology; ontogenesis; phylogeny
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2021.775570

Many hypotrich genera, including , are taxonomically challenging and in a need of integrative revision. Using morphological data, molecular phylogenetic analyses, and internal transcribed spacer 2 (ITS2) secondary structures, we attempt to cast more light on species relationships within the genus . The present multifaceted approach reveals that (1) a large-sized species with numerous macronuclear nodules, isolated from sandy littoral sediments in southern China, is new to science and is endowed here with a name, spec. nov.; (2) two other Chinese populations previously identified as represent undescribed species; and (3) multigene phylogeny is more robust than single-gene trees, recovering the monophyly of the genus with high bootstrap frequency. Additionally, ITS2 secondary structures and the presence of compensatory base changes in helices A and B indicate the presence of four distinct taxa within the molecularly studied members of the genus . Molecular data are more suitable for delimitation of species than morphological characters as interspecific pairwise genetic distances of small subunit (18S) rDNA, ITS1-5.8S-ITS2, and large subunit (28S) rDNA sequences do not overlap, whereas ranges of multiple morphometric features might transcend species boundaries.