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Protistology ■ 79
THE DRAFT GENOME OF KIPFERIA BIALATA REVEALS THAT THE GAIN OF FUNCTION CONTRIBUTES THE MASSIVE REDUCTIVE EVOLUTION IN METAMONADA Tanifuji G.12, Takabayashi S.2, Kume K.2, Takagi M.T.2, Inagaki Y.I.2, Hashimoto T.2
1 - National Museum of Nature and Science
2 - University of Tsukuba [email protected]
Metamonada is a unicellular eukaryotic group known to consist of free-living and parasitic organisms. Almost all of metamonads have adapted to anaerobic or micro aerobic environments, and lost the several mitochondrial functions such as the oxidative phosphorylation. The biological pathways localized in those reduced mitochondria (so-called mitochondrion-related organelles or MROs) vary depending on the species. The nuclear genome of the model parasites such as Giradia intestinalis was also reduced in terms of the genome structure and the number of coding proteins, presumably throughout the adaptive evolution to the intra-cellular lifestyle. However, little is known how the genome reduction progressed in this parasite. Here, we present the draft genome sequence of the free-living Kipferia bialata, which is a phylogenetic relative of G. intestinalis, and compare it to the genomes of the model metamonad parasites, G. intestinalis and Trichomonas vaginalis. Our data show that 1) K. bialata possesses two substrate-level phosphorylation pathways—one is homologous to that in G. intestinalis and the other is to that in T. vaginalis, suggesting the once expansion of ATP synthesis pathways in the metamonad evolution to reach parasitic life style of G. intestinalis, and 2) no variant-specific surface protein (VSP), possibly an evasion mechanism of the host immunity in G. intestinalis, was detected from K. bialata genome, suggesting that the VSPs were acquired somehow on the line leading to G. intestinalis after the divergence of K. bialata. In sum, our results suggested that the gain of function/protein conversely contributed to the massive reductive evolution in metamonads.
AUTOTROPHIC PROTISTS OF THE LITTLE RIVER AND ITS TRIBUTARIES (ON THE EXAMPLE OF THE ZIVIL, THE REPUBLIC OF CHUVASHIA) Tarasova N.G.1, Burkova T.N.2.
1 - Institute of ecology of the Volga river basin ofRAS
2 - Toglyatti state University, Russia [email protected]
Small river is a complex natural object. Natural and human-induced change affect the health of its components. In the summer of 2013 was a study of
the algaeflora in plankton of river Zivil and 10 of its tributaries. In the composition of autotrophic plankton were recorded 105 species of protists. They accounted for 25% of the total species richness of the algalflora. In the Zivil was met 77 species of protists, in the rivers — 67. However, the average number of species in one sample in the tributaries was 6,7, and in the Zivil — 2,75. The qualitative composition of protists of Zivil and its tributaries are similar. The coefficient of species similarity of Sorenson calculated for the Zivil and its tributaries - 53%. Abundance and biomass of the protists was significantly higher in the Zivil, compared to the tribu-taries. The contribution of protists to the formation of the total abundance and biomass of phytoplank-ton was also higher in the river Zivil. Thus, the average specific number of species of protists in the little river is lower than in its tributaries. This is probably due to a much more varied conditions. However, in the river compared to the tributaries, the indices of quantitative development of higher protists. Great is the contribution ofprotist in the formation ofthe total abundance and biomass of phytoplankton in the Zivil, compared to the tributaries.
CHANGE COMMUNITY OF AUTOTROPHIC
PROTISTS FROM THE SOURCE TO THE
MOUTH OF A SMALL RIVER (ON THE
EXAMPLE OF THE ZIVIL, THE REPUBLIC
OF CHUVASHIA)
Tarasova N.G., Tretyakova T.P.
Institute of ecology ofthe Volga river basin, Toglyatti,
Toglyatti state University, Russia
Zivil river — inland waterway of the republic, the right tributary of the Volga. The study of the biota of the river began in 1913. In the summer of 2013 conducted a comprehensive study of the reservoir from the headwaters to the mouth. In the composition of algaflora was discovered 77 species of protists from divisions Chryzophyta, Cryptophyta, Dinophyta, Euglenophyta and Raphydophyta. This is 25% of the total species richness of the algal flora. The river experiences significant agricultural load, so the maximum diversity differed the division Euglenophyta. The specific number of species of protists varied from 3 to 28. Maximum species richness was registered in the region of the mouth of the Warm river, experiencing significant development pressure. In most cases, the increase in species richness ofprotists after the confluence ofthe river tributaries. From its source to the mouth of the river is the growth of the species richness of protists. The population and biomass ofprotists also increase
80 • "PROTIST—2016
from the headwaters to the mouth. The maximum development of the protists received at the mouth of Warm Creek. Here the number of protists in 50, and biomass 25 times higher than the average. Thus, the protists of a small river with significant agricultural load, have high species diversity. The trends of increasing species richness, abundance and biomass of protists from the source to the mouth of the watercourse.
THE PROTISTAN SPECIES MAXIMUM CONCEPT AND ITS IMPLICATIONS TO INVASIVE BIOLOGY Telesh I.V.
Zoological Institute RAS, St. Petersburg, Russia [email protected]
The paper discusses possible implications of the novel protistan species maximum concept for the predictive modelling of ecosystem resilience and vulnerability to alien species invasions. Recent development of the protistan species maximum concept for the challenging zone of critical salinity 5-8%o (horohalinicum), where macrozoobenthos experience destructive osmotic stress (Telesh et al., 2011), is presented. This concept arose from the discovery that not all brackish waters are poor in plankton species, which was exemplified by the Baltic Sea data. The concept has gradually evolved to the understanding that in the environment with sharp salinity fluctuations community regulations and life strategies of small unicellular planktonic organisms differ substantially from those of large multicellular bottom-dwellers. Special efforts were undertaken to define the major organismal traits and environmental factors responsible for this new peculiar biodiversity pattern. Phytoplankton cell size, seasonality in development, and water salinity were tested as key characteristics. A long-term (1972-2006) phytoplankton dataset from the Baltic Sea ("the sea of invaders") was analyzed by means of correlation analysis, non-metric multidimensional scaling, and rarefaction analysis. Results prove statistically that algal cell size minimum underpins the protistan species maximum in the horohalinicum. Seasonality in phytoplankton development promotes the shift in community composition towards dominance of the small-sized species in the critical salinity regions. The protistan species maximum in the horohalinicum is largely backed up by the significant between-sample variation in species richness in the highly changeable brackish-water environment. The work was funded in part by the Russian Foundation for Basic Research, project 15-29-02706.
PROFILING THE PROTOZOAN TAXONO-MIC AND FUNCTIONAL DIVERSITY OF AN ANTARCTIC DRY VALLEY Thompson A.R.1, Buelow H.2, Takachs-Vesbach C.2, Adams B.J.1
1 - Department ofBiology, Brigham Young University
2 - Department ofBiology, University of New Mexico [email protected]
The McMurdo Dry Valleys of Victoria Land Antarctica are some of the harshest terrestrial habitat on earth. At 78°S and 163°E, the average temperature of the region is <-20°C, precipitation is <10 cm yr -1 and the growing period during the austral summer lasts only a few months when the landscape is warmed enough for glacier-fed streams to flow and some permafrost to thaw. Life is almost entirely microbial in these valleys and the landscape is dominated by extremely dry soils that are highly saline, oligotrophic, basic in pH and subject to frequent freeze-thaw cycles. This system is a great outdoor laboratory as the extreme conditions have reduced complexity such that intricate interactions between soil taxa can be unraveled. Our research aims to investigate protozoan diversity in these valleys in order to understand fundamental aspects of protozoan ecology that can be applied broadly. However, our understanding of the taxonomic diversity, distribution and functional roles of these organisms in these valleys is still lacking. To begin to address this, a variety of soils were sampled from two valley systems and metagenome and transcriptome datasets were constructed using next generation sequencing. Our results so far suggest that there is greater taxonomic and functional diversity than was previously thought present, with relatively high representation from many major ciliate and cercozoan clades. Future sequencing efforts will undoubtedly shed more light on distribution and richness of individual OTUs.
MANY PREVIOUSLY INCERTAE SEDIS AMO-EBOZOANS FIND A HOME WITHIN THE CENTRAMOEBIDA
Tice A.K.12, Shadwick L.L.3, Spiegel F.W.3, Geisen S.4, Fiore-Donno A.M.4, Bonkowski M.4, Dumack K.4, Kang S.12, Brown M.W.12
1 - Department ofBiological Sciences, Mississippi State University, Mississippi State, MS, 39762
2 - Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS, 39762
3 - Department of Biological Sciences, University of Arkansas, Fayetteville, AR, 72701
4 - University of Cologne, Institute of Zoology,
