Научная статья на тему 'Testate amoeba transfer function performance along localised hydrological gradients'

Testate amoeba transfer function performance along localised hydrological gradients Текст научной статьи по специальности «Биологические науки»

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Текст научной работы на тему «Testate amoeba transfer function performance along localised hydrological gradients»

84 • "PROTIST—2016

between them. Morphological analysis of selected strains from the major clade, which we consider as the genus Monocercomonoides, failed to find suitable characters for species delineation and it is also very difficult to assign lineages to described species. Based on the morphology and host origin, we assume that the lineage containing Chinchilla isolate PA203, and isolates from guinea pig and Chameleo cristatus represent species M. exilis.

CILIOFAUNA OF NATURAL AND ARTIFICIAL ECOSYSTEMS OF KHABAROVSK TERRITORY

Tribun M.M., Zhykov A.V., Nikitina L.I. Far Eastern State Transport University tribunmikhail@gmail.com

Environmental degradation due to pollution by industrial, agricultural and municipal waste gave rise to serious problems, associated with the violation of the ecological balance in ecosystems and the biosphere. Ciliata - an important object in the model laboratory experiments, as they are used as an indicator of the degree of human impact on the environment. Sampling was carried out in small rivers of the Khabarovsk territory (rivers Krasnaya, Chernaya, Berezovaya) and aeration tanks in Khabarovsk (town Berezovii). During inventory ciliofauna has been identified 152 species of ciliates. The greatest number of species represented Oligohymenophorea class - 33 and Vorticellidae family - 12 species. 3 species of ciliates were eurybiontic (Paramecium caudatum, Colpidium campylym, Uronema marinum). Species ciliofauna similarity between small rivers and aeration tanks is 30% (according to Sorensen coefficient). Ciliata specific types of small rivers Khabarovsk - 14 (32% of the number of species recorded in small rivers), in aeration tanks - 32 (57%). Specific types belonged Armophorea classes - 3 kinds, Litostomatea - 3 kinds, Phyllopharyngea - 8 species, Oligohymenophorea - 13 species. Thus, faunal analysis of ciliofauna aquatic ecosystems Khabarovsk shows how the presence of similar species found in a variety of biological communities and the presence of specific representatives. In particular, this phenomenon is characteristic of biocenosis aeration.

OVERVIEW OF THE WHOLE SPECTRUM OF MITOCHONDRIAL DIVERSITY WITHIN THE CILIATE CLADE

Tsaousis A.D.12, Williams L.T.12, Gentekaki E.3, Lynn D.4, van der Geizen M.5, Wass M.N.2

1 - Laboratory of Molecular and Evolutionary Parasitology

2 - School of Biosciences, University of Kent

3 - School ofScience, Mae Fah Luang University

4 - University ofBritish Columbia

5 - School of Biosciences, University of Exeter Ai.Tsaousis@kent.ac.uk

Mitochondria are important organelles in all eukaryotes and their protein composition and function(s) depend on the lifestyle of the organism harboring them. While being very well studied, their functional distribution amongst ciliates remains a dark box. The Ciliophora group is currently one of the most studied lineages of single-cell eukaryotes, mainly due to their abundance in diverse habitats. Despite this, investigations on the cell biology and the functional diversification of their organelles have been limited, with the exception of certain species, mainly Paramecium, Tetrahymena and Nyctotherus. These organisms have been shown to harbor either typical mitochondria or hydrogen-producing mitochondria, while their mitochondrial genome has an unusual codon usage. In this project, we used the recently acquired transcriptomic and genomic data to predict the functional diversity of mitochondria and related organelles within the group of ciliates. Our analyses demonstrate that members of the ciliates harbor distinctive classes of mitochondria, with a variety of functions and adaptations. Two species have been predicted to have remnant mitochondria (mitosomes) and one of them hydrogen-producing mitochondria (hydrogenosomes). Surprisingly, we are currently observing the whole spectrum of functional classification of mitochondria just within ciliates; Ciliophora is an exceptional model group to monitor in real time the functional adaptations of mitochondria.

TESTATE AMOEBA TRANSFER FUNCTION PERFORMANCE ALONG LOCALISED HYDROLOGICAL GRADIENTS Tsyganov A.N.1, Mityaeva O.A.1, Mazei Yu.A.12, Payne R.J.13

1 - Department of Zoology and Ecology, Penza State University, Krasnaya str. 40, Penza, 440026, Russia

2 - Department ofHydrobiology, Lomonosov Moscow State University, Leninskiyegory, 1, Moscow, 119991, Russia

3 - Environment Department, University of York, Heslington, York YO10 5DD, United Kingdom andrey.tsyganov@bk.ru

Testate amoeba transfer functions are widely used for reconstruction ofpalaeo-hydrological regime in peatlands. However, the limitations ofthis approach have become apparent with increasing attention to validation and assessing sources of uncertainty. This paper investigates effects of peatland type and

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sampling depth on the performance of a transfer function using an independent test-set from four Sphagnum-dominated sites in European Russia (Penza Region). We focus on transfer function performance along localised hydrological gradients, which is a useful analogue for predictive ability through time. The performance of the transfer function with the independent test-set was generally weaker than for the leave-one-out or bootstrap cross-validations. However, the transfer function was robust for the reconstruction of relative changes in water-table depth, provided the presence ofgood modern analogues and overlap in water-table depth ranges. When applied to subsurface samples, the performance of the transfer function was reduced due to selective decomposition, the presence of deep-dwelling taxa or vertical transfer of shells. Our results stress the importance of thorough testing of transfer functions, and highlight the role of taphonomic processes in determining results. Further studies of stratification, taxonomy and taphonomy of testate amoebae will be needed to improve the robustness of transfer function output. This research was funded by the Russian Scientific Fund (grant 14-14-00891) and grant ofthe President of Russian Federation (MD-7930.2016.4).

CELL COAT EVOLUTION AND PHYLOGENY OF DACTYLOPODID AMOEBAE (AMOE-BOZOA, DISCOSEA) Udalov Ilya A.

DepartmentofInvertebrate Zoology, Faculty ofBiology, Saint-Petersburg State University, Universitetskaya nab. 7/9,199034 St. Petersburg, Russia chlamydophrys@gmail.com

An amoebae order Dactylopodida was established on the base ofthe results of the molecular phylogenetic analysis. To date it includes genera Vexillifera, Cunea, Pseudoparamoeba, Korotnevella, Paramoeba and Neoparamoeba. All representatives of this order share the ability to form non-furcating finger-shaped subpseudopodia (dactylopodia), which considered as morphological synapomorphy for this group. Up to now all these genera were distinguished by morhological features: peculiarities of locomotive form, presence or absence of kinetoplastid endo-symbiont (Perkinsela amoebae-like organism, or PLO) and structure ofthe cell coat. The details ofthe cell coat evolution in Dactylopodida are still unclear. Recent studies shown that situation with generic distinctions in this group actually is much more complex. One of the studied species formally fits the diagnosis of the genus Korotnevella, because it has scales and lacks PLO. At the same time its

18S rRNA gene sequence robustly groups with Pseudoparamoeba pagei (which lacks both PLO and scales) and never branches among those of Korotnevella spp. Thus the situation described above shows that to the moment the boundary between two genera Pseudoparamoeba and Korotnevella can be correctly drawn only on the basis of 18S rDNA sequence. Our data probably mean that actually the presence of scales is a primitive feature for a whole clade, which unifies genera Pseudoparamoeba, Korotnevella, Paramoeba and Neoparamoeba. Within this group scales retained in some species and lost in others.

ECOLOGICAL STUDY OF THRAUSTOCHY-TRIDS (LABYRINTHULEA, STRAMENO-PILES)

Ueda M.12, Doi K.12, Nomura Y.3, Nakajima M.4, Honda D.32

1 - Graduate School of Natural Science, Konan University, Japan

2 - Institute for Integrative Neurobiology, Konan University, Japan

3 - Faculty of Science and Engineering, Konan University, Japan

4 - Research Institute ofEnvironment, Agriculture and Fisheries, Osaka Prefecture, Japan dhonda@konan-u.ac.jp

Thraustochytrids have been recognized as important decomposers in the marine ecosystem. However, in many cases, this recognition is based on the short investigation of the biomass of whole thraustochytrids without distinguishing the species. In this study, we investigated the seasonal changes of biomass and species composition ofthraustochytrids by continuous monitoring at river mouths and coastal areas in Japan for five years. Remarkable peaks of cell numbers of the thraustochytrids were observed in early summer and/or summer at the river mouths. This phenomenon was named "thraustochytrid spikes". Thraustochytrid biomass didn't correlate with chlorophyll a, but it seemed that the peaks occurred after the decrease in salinity. This phenomenon probably suggested that the thraustochytrid biomass is affected by the supply of the terrestrial organic matter from river water. Although thraustochytrid biomass was only 1.59% that of bacterial biomass, the fixed energy (as biomass) transferred directly from thraustochytrids to zooplankton was estimated to be 15.9% of that transferred from bacterioplankton via phagotrophic protists. Moreover, a clear seasonal succession of thraustochytrid species was repeatedly observed every year. However, species composition differs

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