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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 goro.tanifuji.sci@gmail.com
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 tnatag@mail.ru
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
tnatag@mail.ru
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
