Volume 56, Issue 3

2017

Publication date: 13.12.2017

Licence: CC BY-NC-ND

Editorial team

Editor-in-Chief Krzysztof Wiąckowski

Issue content

Actinomycin D as an Epimutagen in Protists

Zoya I. Uspenskaya, Alexander L. Yudin

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 139-147

https://doi.org/10.4467/16890027AP.17.012.7493

A previously unrecorded property of actinomycin D, a well-known antibiotic, was discovered in the course of long-term genetic research on the amoeba Amoeba proteus and the ciliate Dileptus anser. In these protists actinomycin D can induce an unusual type of hereditary variation, which we refer to as the inheritable destabilization of characters. A number of features indicate that this variation is epigenetic, that is, not caused by mutations in the DNA. Therefore, actinomycin D may be considered as an inducer of epigenetic inheritable changes, in other words, as an epimutagen.

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Cortical Localization of α- and γ-Tubulin and the Assembly of Cortical Microtubule Cytoskeleton in Hypotrichous Ciliate Euplotes eurystomus

Xin Sheng, Yan Sheng, Yuehua Liu, Junhua Wang

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 149-160

https://doi.org/10.4467/16890027AP.17.013.7494

This study aimed to investigate the assembly characteristics of ciliature and cortical microtubules and the localization of tubulins in different depths and regions of the cortex. The hypotrichous ciliates have closely arranged cilia and a highly complex microtubular system. Direct fluorescence and immunofluorescence labeling were used to observe ciliary organelles and cortical microtubular cytoskeleton in Euplotes eurystomus. An immunofluorescence analysis demonstrated that α-tubulin localized to the ventral and dorsal ciliary organelles and their associated microtubules, while γ-tubulin localized to the basal bodies of ciliary organelles, macronuclear membrane, and excretory pore of a contractile vacuole in the interphase. A direct fluorescence analysis showed that the ciliature and cortical microtubules in the deep cortex were more clearly marked by fluorescent taxoid (FLUTAX). Interestingly, α- and γ-tubulins also colocalized to the ringlike ciliary base–associated microtubules of dorsal kineties. The short microtubular bundles between the bases of transverse cirri could be marked by FLUTAX and γ-tubulin rather than α-tubulin, suggesting that tubulins in cortical microtubules in E. eurystomus varied, and the differentiation of cortical microtubules in the hypotrichous ciliate tended to be versatile. Also, during morphogenesis, γ-tubulin also localized to the base of ciliary primordium, where new basal bodies were formed, suggesting that the endocellular position of γ-tubulin in ciliates was related to basal bodies and regulated by the cell cycle. This study might help understand the assembly characteristics and tubulin composition of microtubules in different depths and regions of the cortex in hypotrichous ciliate E. eurystomus.

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Taxonomical reinvestigation of the colepid species Pinacocoleps pulcher (Spiegel, 1926) Foissner et al., 2008 (Ciliophora: Prorodontida: Colepidae)

Ji Hye Moon, Ji Hye Kim, Jae-Ho Jung

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 161-169

https://doi.org/10.4467/16890027AP.17.014.7495

Brackish water populations of Pinacocoleps pulcher were collected from a lagoon in Korea. This species has never been described using silver impregnation and nuclear small subunit ribosomal RNA (SSU rRNA) gene. In the present study, we investigated the morphological and molecular attributes of P. pulcher using standard methods. The morphology was studied based on observations of live materials, silver-impregnated preparations, and scanning electron microscopy. The morphological characteristics are as follows: body size 80–90 × 40–50 µm in vivo, shape broadly ellipsoidal, body cross-section ellipsoidal, about seven anterior spines and about seven posterior spines, approximately 21 somatic ciliary rows, one macronucleus and one micronucleus, and a single caudal cilium. The SSU rRNA gene tree supports a sister relationship of P. pulcher to the genus Apocoleps, not P. tesselatus.

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Rumen Ciliate Biota of Domestic Cattle (Bos taurus taurus) in İstanbul, Turkey and Infraciliature of Metadinium medium (Entodiniomorphida, Ophryoscolecidae)

Gözde Gürelli, Fatma Tül Büşra Akman

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 171-180

https://doi.org/10.4467/16890027AP.17.015.7496

The species composition and distribution of ciliates were investigated in the rumen contents of 15 domestic cattle (Bos taurus taurus L.) living in the European part of İstanbul, Turkey. Thirty-five species and 13 morphotypes belonging to 13 genera were identified. The density of rumen ciliates in cattle was 31.8 (± 21.3) × 104 cells ml−1, and the mean number of ciliate species per host was 12.9 ± 4.4. Of the ciliate species, Dasytricha ruminantium, Entodinium simulans, and Isotricha prostoma were the most abundant, each with a prevalence of 93.3%, whereas Diplodinium anisacanthum, D. dogieli, D. rangiferi, Enoploplastron triloricatum, Metadinium medium, and Ostracodinium munham were detected only in one animal (6.7% prevalence). Eodinium posterovesiculatum m. bilobosum and D. dogieli are new host records for cattle in Turkey. The infraciliature of M. medium (Entodiniomorphida, Ophryoscolecidae) was examined and detected for the first time. The buccal infraciliature of M. medium was composed of three polybrachykineties, a kinety loop, and paralabial kineties. A large dorso-adoral polybrachykinety, a gentle S-shaped curved vestibular polybrachykinety, and a kinety loop between the dorso-adoral polybrachykinety and adoral polybrachykinety were characteristics. Because of these features, M. medium-type buccal infraciliature was between the Ostracodinium gracile-type buccal infraciliature and the Ostracodinium mammosum-type buccal infraciliature.

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Allovahlkampfia minuta nov. sp., (Acrasidae, Heterolobosea, Excavata) a New Soil Amoeba at the Boundary of the Acrasid Cellular Slime Moulds

Alvaro De Obeso Fernadez Del Valle, Sutherland K. Maciver

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 181-189

https://doi.org/10.4467/16890027AP.17.016.7497

We report the isolation of a new species of Allovahlkampfia, a small cyst-forming heterolobosean soil amoeba. Phylogenetic analysis of the 18S rDNA and the internal transcribed spacers indicates that Allovahlkampfia is more closely related to the acrasids than to other heterolobosean groups and indicates that the new strain (GF1) groups with Allovahlkampfia tibetiensis and A. nederlandiensis despite being significantly smaller than these and any other described Allovahlkampfia species. GF1 forms aggregated cyst masses similar to the early stages of Acrasis sorocarp development, in agreement with the view that it shares ancestry with the acrasids. Time-lapse video microscopy reveals that trophozoites are attracted to individuals that have already begun to encyst or that have formed cysts. Although some members of the genus are known to be pathogenic the strain GF1 does not grow above 28oC nor at elevated osmotic conditions, indicating that it is unlikely to be a pathogen.

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Response of Sphagnum Testate Amoebae to Drainage, Subsequent Re-wetting and Associated Changes in the Moss Carpet – Results from a Three Year Mesocosm Experiment

Isabelle Koenig, Florence Schwendener, Matthieu Mulot, Edward A. D. Mitchell

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 191-210

https://doi.org/10.4467/16890027AP.17.017.7498

Sphagnum peatlands represent a globally significant pool and sink of carbon but these functions are threatened by ongoing climate change. Testate amoebae are useful bioindicators of hydrological changes, but little experimental work has been done on the impact of water table changes on communities.

Using a mesocosm experimental setting that was previously used to assess the impact of drought disturbance on communities and ecosystem processes with three contrasted water table positions: wet (–4 cm), intermediate (–15 cm) and dry (–25 cm), we studied the capacity of testate amoeba communities to recover when the water table was kept at –10 cm for all plots. The overall experiment lasted three years. We assessed the taxonomic and functional trait responses of testate amoeba communities. The selected traits were hypothesised to be correlated to moisture content (response traits: shell size, aperture position) or trophic role (effect traits: mixotrophy, aperture size controlling prey range).

During the disturbance phase, the mixotrophic species Hyalosphenia papilio dominated the wet and intermediate plots, while the community shifted to a dominance of “dry indicators” (Corythion dubium, Nebela tincta, Cryptodifflugia oviformis) and corresponding traits (loss of mixotrophy, and dominance of smaller taxa with ventral or ventral-central aperture) in dry plots. During the recovery phase we observed two contrasted trends in the previously wet and intermediate plots: communities remained similar where the Sphagnum carpet remained intact but species and traits indicators of drier conditions increased in plots where it had degraded. In the former dry plots, indicators and traits of wet conditions increased by the end of the experiment.

This is one of the first experiment simulating a disturbance and subsequent recovery in ex-situ mesocosms of Sphagnum peatland focusing on the response of testate amoebae community structure as well as functional traits to water table manipulation. The results generally confirmed that testate amoebae respond within a few months to hydrological changes and thus represent useful bioindicators for assessing current and past hydrological changes in Sphagnum peatlands.

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Testate Amoeba Diversity of a Poor Fen on Mineral Soil in the Hilly Area of Central Honshu, Japan

Satoshi D. Shimano, Anatoly Bobrov, Manfred Wanner, Mariusz Lamentowicz, Yuri Mazei, Taisuke Ohtsuka

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 211-216

https://doi.org/10.4467/16890027AP.17.018.7499

We present a short note on the species composition of testate amoebae in a poor fen on mineral soil near the Pacific Coast in the hilly area of Central Honshu, Japan. In total 45 species and subspecific taxa belonged to 21 genera and 14 families of testate amoebae were recorded. Eight species and nine subspecies are newly recorded from Japan. However, most species from the list can be considered as distributed worldwide and associated mostly to oligotrophic/acid Sphagnum conditions.

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Observations of Apparent Lorica Variability in Salpingacantha (Ciliophora: Tintinnida) in the Northern Pacific and Arctic Oceans

John R. Dolan, Eun Jin Yang

Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 217-220

https://doi.org/10.4467/16890027AP.17.019.7500

Species identifications of tintinnid ciliates are based on characteristics of the lorica housing the ciliate cell. Molecular characterization of tintinnid ciliates has revealed the occurrence of cryptic species, genetically distinct forms with similar loricas, as well as polymorphic species in which genetically identical forms have distinct loricas. Among this latter category may be forms currently recognized as species of the genus Salpingacantha, erected by Kofoid and Campbell for forms originally described as varieties of species of Salpingella with ‘teeth’ on the margin of the lorica oral opening. Some workers have expressed the opinion that the genus is artificial and notably a recent molecular study suggested that Salpingella and Salpingacantha are likely synonyms. In this short communication we report on finding morphologically distinct loricas (containing ciliate cells) of Salpingacantha in single samples from stations in the North Pacific and Arctic Oceans in 2010, 2015 and 2016. We found up to 5 distinct Salpingacantha forms co-occurring, often with abundant Salpingella acuminata populations suggesting that some Salpingacantha species may be varieties of Salpingella acuminata. While we lack genetic data needed for definitive proof of polymorphism, here we document remarkable gradual gradients in morphology suggestive of polymorphism.

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Słowa kluczowe: actinomycin D, Amoeba proteus, Dileptus anser, epigenetic variation, epimutagen, inheritable destabilization of characters, basal body, ciliature microtubular organelles, E. eurystomus, FLUTAX, immunofluorescence, γ-tubulin, ciliate, redescription, taxonomy, SSU rDNA sequences, brackish water, Korea, Cattle, ciliate, Entodiniomorphida, infraciliature, İstanbul, Metadinium medium, Ophryoscolecidae, rumen, Mesocosm experiment, Testate amoebae, Functional traits, Recovery, Disturbance, Sphagnum peatlands, bio-indicators, water table depth, testate amoebae, mineral soil, fen, Japan, Sphagnum, Rhizaria, Amoebozoa, Stramenopiles, microzooplankton, plankton, polymorphism, tintinnida

Volume 56, Issue 3

2017 Next

Issue content

2017