Dataset Information

Morphological and molecular phylogeny of dileptid and tracheliid ciliates: resolution at the base of the class Litostomatea (Ciliophora, Rhynchostomatia).

ABSTRACT: Dileptid and tracheliid ciliates have been traditionally classified within the subclass Haptoria of the class Litostomatea. However, their phylogenetic position among haptorians has been controversial and indicated that they may play a key role in understanding litostomatean evolution. In order to reconstruct the evolutionary history of dileptids and tracheliids, and to unravel their affinity to other haptorians, we have used a cladistic approach based on morphological evidence and a phylogenetic approach based on 18S rRNA gene sequences, including eight new ones. The molecular trees demonstrate that dileptids and tracheliids represent a separate subclass, Rhynchostomatia, that is sister to the subclasses Haptoria and Trichostomatia. The Rhynchostomatia are characterized by a ventrally located oral opening at the base of a proboscis that carries a complex oral ciliature. We have recognized two orders within Rhynchostomatia. The new order Tracheliida is monotypic, while the order Dileptida comprises two families: the new, typically bimacronucleate family Dimacrocaryonidae and the multimacronucleate family Dileptidae. The Haptoria evolved from the last common ancestor of the Litostomatea by polarization of the body, the oral opening locating more or less apically and the oral ciliature simplifying. The Trichostomatia originated from a microaerophylic haptorian by further simplification of the oral ciliature, possibly due to an endosymbiotic lifestyle.

SUBMITTER: Vdacny P

PROVIDER: S-EPMC3234341 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Morphological and molecular phylogeny of dileptid and tracheliid ciliates: resolution at the base of the class Litostomatea (Ciliophora, Rhynchostomatia).

Vďačný Peter P Orsi William W Bourland William A WA Shimano Satoshi S Epstein Slava S SS Foissner Wilhelm W

European journal of protistology 20110608 4

Dileptid and tracheliid ciliates have been traditionally classified within the subclass Haptoria of the class Litostomatea. However, their phylogenetic position among haptorians has been controversial and indicated that they may play a key role in understanding litostomatean evolution. In order to reconstruct the evolutionary history of dileptids and tracheliids, and to unravel their affinity to other haptorians, we have used a cladistic approach based on morphological evidence and a phylogeneti ...[more]

PMID: 21641780

Similar Datasets

Project description:BackgroundThe taxonomic classification of the suborder Tintinnina Kofoid & Campbell, 1929, a species-rich group of planktonic ciliated protistans with a characteristic lorica, has long been ambiguous largely due to the lack of cytological and molecular data for most species. Tintinnopsis is the largest, most widespread, and most taxonomically complex genus within this group with about 170 species occurring in nearshore waters. Previous molecular phylogenetic studies have revealed that Tintinnopsis is polyphyletic.ResultsHere we document the live morphology, infraciliature, gene sequences, and habitat characteristics of three poorly known tintinnine species, viz. Tintinnopsis karajacensis Brandt, 1896, Tintinnopsis gracilis Kofoid & Campbell, 1929, and Tintinnopsis tocantinensis Kofoid & Campbell, 1929, isolated from the coastal waters of China. Based on a unique cytological feature (i.e., an elongated ciliary tuft with densely arranged kinetids) in the former two species, Antetintinnopsis gen. nov. is erected with Antetintinnopsis hemispiralis (Yin, 1956) comb. nov. (original combination: Tintinnopsis hemispiralis Yin, 1956) designated as the type species. Moreover, A. karajacensis (Brandt, 1896) comb. nov. (original combination: Tintinnopsis karajacensis Brandt, 1896) and A. gracilis (Kofoid & Campbell, 1929) comb. nov. (original combination: Tintinnopsis gracilis Kofoid & Campbell, 1929) are placed in a highly supported clade that branches separately from Tintinnopsis clades in phylogenetic trees based on SSU rDNA and LSU rDNA sequence data, thus supporting the establishment of the new genus. One other species is assigned to Antetintinnopsis gen. nov., namely A. subacuta (Jörgensen, 1899) comb. nov. (original combination Tintinnopsis subacuta Jörgensen, 1899).ConclusionsThe findings of the phylogenetic analyses support the assertion that cytological characters are taxonomically informative for tintinnines. This study also contributes to the broadening of our understanding of the tintinnine biodiversity and evolution.

Project description:Simple Summary Rare organisms represent a challenge for researchers in all fields of study in biology. In the realm of ciliatology, the genera Dactylochlamys and Legendrea are considered to be such cases. Very little information has accrued in over a century since their first descriptions; only a few published reports, online images or videos of rarely encountered individual specimens exist. Dactylochlamys and Legendrea are also morphologically remarkable for their likely independently evolved tentacle-like structures. Recently, the first molecular data were published for the species L. loyezae. In our study, we present more robust phylogenetic analysis based on three molecular markers of Dactylochlamys pisciformis and all of the three known Legendrea species, showing that they likely represent a new anaerobic lineage of ciliates. We first provide a detailed morphological characterization of both genera using modern microscopy and staining methods. We identify and discuss the bacterial (Syntrophaceae) and archaeal endosymbionts harbored by both genera based on 16S rRNA gene sequences. We also discovered that Legendrea preys on gastrotrichs, which is supported by molecular data and a unique video material documenting the feeding behavior of one Legendrea species. This study brings essential information needed to better understand the phylogeny, life strategies, and rarity of these organisms and emphasizes the importance of citizen science. Abstract Free-living anaerobic ciliates are of considerable interest from an ecological and an evolutionary standpoint. Extraordinary tentacle-bearing predatory lineages have evolved independently several times within the phylum Ciliophora, including two rarely encountered anaerobic litostomatean genera, Legendrea and Dactylochlamys. In this study, we significantly extend the morphological and phylogenetic characterization of these two poorly known groups of predatory ciliates. We provide the first phylogenetic analysis of the monotypic genus Dactylochlamys and the three valid species of Legendrea based on the 18S rRNA gene and ITS-28S rRNA gene sequences. Prior to this study, neither group had been studied using silver impregnation methods. We provide the first protargol-stained material and also a unique video material including documentation, for the first time, of the hunting and feeding behavior of a Legendrea species. We briefly discuss the identity of methanogenic archaeal and bacterial endosymbionts of both genera based on 16S rRNA gene sequences, and the importance of citizen science for ciliatology from a historical and contemporary perspective.

Dataset Information

Morphological and molecular phylogeny of dileptid and tracheliid ciliates: resolution at the base of the class Litostomatea (Ciliophora, Rhynchostomatia).

Publications

Morphological and molecular phylogeny of dileptid and tracheliid ciliates: resolution at the base of the class Litostomatea (Ciliophora, Rhynchostomatia).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets