Phylogenetic position of the pelobiont Mastigamoeba aspera and revision of the family Mastigamoebidae (Archamoebae, Pelobiontida).

In this study, we presented the results of our molecular phylogenetic analysis of Archamoebae using a newly obtained sequence of the 18S rRNA gene of Mastigamoeba aspera, the type species of the genus. In addition, we characterized the general organization of the tubulin cytoskeleton of M. aspera by immunofluorescent microscopy and TEM. Our findings allowed us to revise the family Mastigamoebidae and establish within it two subfamilies: Mastigamoebinae for the genus Mastigamoeba and Seraviniinae subfam. nov. for the genera Seravinia gen. nov., Paramastigamoeba gen. nov., Iodamoeba and Endolimax. The type genera Mastigamoeba and Seravinia are clearly distinguished by the structure of the basal apparatus of flagella. In addition, the tubulin cytoskeleton of several Mastigamoeba spp. contains a rim of microtubules around the nuclei.

Ciliates from the faeces of the free-ranging dromedary from Oman: Morphology and molecular phylogeny.

Ciliates Infundibulorium cameli from the faeces of the free-ranging dromedary from Oman were studied using a set of methods of the light and immunofluorescence microscopy and molecular phylogeny. With the use of molecular genetic methods, it was confirmed that the cysts found in the samples simultaneously with trophozoites actually belong to the species I. cameli. Tubulin cytoskeleton organization of trophozoites and cysts of this species were described for the first time. A striking morphological similarity between species I. cameli and Buxtonella sulcata was demonstrated, including the organization of ciliature. Different isolates of I. cameli and B. sulcata formed a common clade on the phylogenetic tree. The level of evolutionary divergence between the 18 S rRNA sequences of I. cameli, B. sulcata and species closest to them according to the results of molecular phylogenetic analysis was estimated. It was demonstrated that the divergence between I. cameli and B. sulcata is extremely low compared to members of other genera included in the analysis. Taxonomic position of I. cameli and B. sulcata was discussed in according to the data of comparative morphology and molecular phylogeny.

Ciliates from the intestine of zoo-kept black rhinoceros, with immunofluorescence microscopic and molecular phylogenetic investigation of Rhinozeta rhinozeta (Litostomatea).

The study of endobiotic ciliates from the intestines of various zoo mammals is important for revealing the influence of various factors on endobiont communities. In this paper we describe the species diversity of endobiotic ciliates from the faeces of the eastern black rhinoceros Diceros bicornis michaeli (male and two females, mother and daughter) kept in the zoo. Seven species of the ciliates were found, among them Rhinozeta rhinozeta, R. triciliata and Prototapirella clypeata were observed in the rhinos only. The other two, Monoposthium sp. and Triplumaria sp., according to their morphology should have been identified as new ciliate species. Successful transmission of the endobionts from parents to the young rhino in the zoo was demonstrated. R. rhinozeta was investigated with the using of the methods of the light and immunofluorescence microscopy and molecular phylogeny. The composition and phylogeny of the family Cycloposthiidae were discussed.

Intestinal ciliates (Ciliophora) from the wild plains zebra (Equus quagga) in South Africa, with notes on the microtubule cytoskeleton organisation.

Investigation of the ciliate communities from the digestive tract of different wild vertebrates is important in context of host-specificity of different ciliate species and the detection of any cases of non-specific infection. Here we present a description and analysis of the fauna of ciliates (Litostomatea, Trichostomatia) inhabiting the intestine of the wild plains zebra (Equus quagga Boddaert, 1785) in South Africa. Nineteen species belonging to 12 genera of five families were found. Five species were specific to Equus quagga; one was also found in Equus zebra; 29 are common to different equids; and one had been previously described from rhinoceros. For the first time, we used immunofluorescent staining to investigate microtubule cytoskeletons in trichostomatids. We found that this staining method is useful for the identification of trichostomatids.

Molecular Phylogeny of Polychaos annulatum (Amoebozoa, Tubulinea, Euamoebida) Shows that Genus Polychaos Belongs to the Family Hartmannellidae.

We have obtained a sequence of the 18S rRNA gene of the species Polychaos annulatum (Penard 1902) Smirnov et Goodkov 1998 using the isolation of a single nucleus from an amoeba cell. Attempts to amplify the 18S rRNA gene from the DNA of this species by conventional PCR were not successful, so we applied the whole genome amplification of the nuclear DNA followed by NGS sequencing. The 18S rRNA gene was found among the resulting contigs. The analysis unexpectedly shows that P. annulatum robustly groups within the family Hartmannellidae, but not Amoebidae. This finding warrants revision of the basic morphological criteria used to classify Euamoebida families and show that "proteus-type" amoebae may belong to other families rather than Amoebidae. This makes taxonomic assignments of such species more complex and the borders between Euamoebida families more nuanced. It is getting evident that molecular data are necessary to clarify the position of species even in this most "classical" order of naked lobose amoebae.

Identification of Pelomyxa palustris Endosymbionts.

Pelomyxa palustris is a giant anaerobic/microaerobic amoeba, characterized by a number of exceptional cytological and physiological features, among them the presumed absence of energy producing organelles and the presence of endosymbiotic bacteria. These endosymbionts have been previously distinguished as: a large rectangular-shaped Gram-variable rod with a central cleft; a slender Gram-negative rod; and a slender Gram-positive rod. Using DNA extracted from P. palustris cysts, we have obtained three SSU rRNA gene sequences. We have determined that these sequences are affiliated to three different prokaryotic genera: Methanosaeta (a methanogenic archaea), Syntrophorhabdus (a syntrophic Gram-negative bacteria) and Rhodococcus (an aerobic chemoorganotrophic Gram-positive bacteria). To our knowledge, it is the first time that Syntrophorhabdus has been described as an endosymbiont in association with a methanogen. Strikingly, no traces of Methanobacterium formicicum could be detected, despite this methanogen had allegedly been isolated from trophozoites of P. palustris. It seems that the host and the endosymbionts have established a multipartite syntrophic consortium resembling to some extent those found in sewage treatment plants.