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Constraints on Phylogenetic Interrelationships among Four Free-living Litostomatean Lineages Inferred from 18S rRNA gene-ITS Region sequences and Secondary Structure of the ITS2 molecule

Publication date: 14.12.2017

Acta Protozoologica, 2017, Volume 56, Issue 4, pp. 255 - 281

https://doi.org/10.4467/16890027AP.17.023.7825

Authors

,
Ľubomír Rajter
Phycology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
Eukaryotic Microbiology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
All publications →
Peter Vďačný
Comenius University, Department of Zoology, Bratislava, Slovakia
All publications →

Titles

Constraints on Phylogenetic Interrelationships among Four Free-living Litostomatean Lineages Inferred from 18S rRNA gene-ITS Region sequences and Secondary Structure of the ITS2 molecule

Abstract

We investigated interrelationships between four free-living litostomatean lineages, using 18S rRNA gene and ITS region sequences as well as the secondary structure of the ITS2 molecules. Our phylogenetic analyses confirmed the deep split of free-living litostomateans into Rhynchostomatia and Haptoria represented here by Haptorida, Pleurostomatida, and Spathidiida. This bifurcation is also corroborated by the signature of the rhynchostomatian and haptorian ITS2 molecules. Specifically, the consensus stems of helices II and III are longer by one base pair in Rhynchostomatia, while the terminal loops of both helices are longer by one or two nucleotide/-s in Haptoria. A close relationship of Pleurostomatida and Haptorida is favored by quartet likelihood-mapping and supported by a 5’-AG vs. CU-3’ motif in the variable part of helix II and by two morphological apomorphies, i.e., meridionally extending somatic kineties and a non-three-rowed dorsal brush. Although monophyletic origin of Spathidiida is poorly supported in phylogenetic trees, the unique motif 5’-GA vs. UC-3’ present in the consensus helix II stem could be an important molecular synapomorphy of spathidiids, apart from the ancestrally anteriorly curved somatic kineties and the three-rowed dorsal brush. The peculiar family Pseudoholophryidae has very likely found its phylogenetic home among spathidiids, as an early branching lineage.

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Information

Information: Acta Protozoologica, 2017, Volume 56, Issue 4, pp. 255 - 281

Article type: Original article

Authors

Phycology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany

Eukaryotic Microbiology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany

Comenius University, Department of Zoology, Bratislava, Slovakia

Published at: 14.12.2017

Article status: Open

Licence: CC BY-NC-ND  licence icon

Percentage share of authors:

Ľubomír Rajter (Author) - 50%
Peter Vďačný (Author) - 50%

Article corrections:

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Publication languages:

English