The Experts below are selected from a list of 1806 Experts worldwide ranked by ideXlab platform
Ewa Przyboś - One of the best experts on this subject based on the ideXlab platform.
-
New stands of species of the Paramecium aurelia complex in Africa and Europe.
Folia biologica, 2014Co-Authors: Maria Rautian, Ewa Przyboś, Marta Surmacz, Natalia LebedevaAbstract:The relevance of geographical distribution and the roles of dispersal and spatial isolation during the speciation of microorganisms are nowadays of great interest. The Paramecium aurelia species complex is a perfect model system to explore these questions given its long history as a study subject and broad distribution. However, the world-wide distribution of the Paramecium aurelia complex (Ciliophora, Protista) still needs study, e.g., sampling in the southern hemisphere has been quite limited, while Europe has been investigated for years, with the majority of aurelia species isolated from here. Recently, new stands of species of the P. aurelia complex were found in southern Europe (Malta, Bulgaria, Cyprus) and in the Czech Republic (P. primaurelia, P. triaurelia, P. octaurelia). In Africa (Republic of South Africa), new stands of P. primaurelia, P. triaurelia, and P. octaurelia were found. Interestingly, the rare species P. triaurelia, and P. octaurelia were found to co-occur both in South Africa (SA 13) and the Czech Republic (CKV 8). Newly established strains were identified to species by crossing with the test strains (the reference strains for the particular species).
-
SPECIES OF THE Paramecium aurelia COMPLEX IN ISRAEL (CILIOPHORA, PROTISTA)
Israel Journal of Zoology, 2013Co-Authors: Ewa PrzybośAbstract:(1995). SPECIES OF THE Paramecium aurelia COMPLEX IN ISRAEL (CILIOPHORA, PROTISTA) Israel Journal of Zoology: Vol. 41, No. 2, pp. 205-206.
-
New stands of species of the Paramecium aurelia complex (Ciliophora, Protozoa) in the Mediterranean region (Italy, Greece, Morocco).
Folia Biologica, 2012Co-Authors: Ewa Przyboś, Maria RautianAbstract:New stands of species of the Paramecium aurelia complex are presented in the paper, P. primaurelia recorded in Italy (Pisa) and in Morocco (Marrakesh), P. biaurelia in Italy (Calabria), P. triaurelia in Morocco (Ifrane), P. pentaurelia in Greece (Kastorya), and P. dodecaurelia in Italy (Padua).
-
Species of the Paramecium aurelia complex in Russia: new stands and overall distribution.
Folia Biologica, 2009Co-Authors: Alexey Potekhin, Ewa Przyboś, Irina Nekrasova, Varvara V. Yashchenko, Maria RautianAbstract:New stands of Paramecium biaurelia, P. triaurelia, P. tetraurelia, P. pentaurelia, P. novaurelia, and P. dodecaurelia were recorded in Russia. Especially interesting is the record of P. novaurelia in Vladivostok, Russian Far East, as it is a very rare species outside of Europe. The distribution of species of the Paramecium aurelia complex in Eurasia with emphasis on findings in Russia is discussed.
-
genetic diversity in the Paramecium aurelia species complex
Molecular Biology and Evolution, 2009Co-Authors: Francesco Catania, Ewa Przyboś, Alexey Potekhin, Francois Wurmser, Michael LynchAbstract:Current understanding of the population genetics of free-living unicellular eukaryotes is limited, and the amount of genetic variability in these organisms is still a matter of debate. We characterized—reproductively and genetically—worldwide samples of multiple Paramecium species belonging to a cryptic species complex, Paramecium aurelia, whose species have been shown to be reproductively isolated. We found that levels of genetic diversity both in the nucleus and in the mitochondrion are substantial within groups of reproductively compatible P. aurelia strains but drop considerably when strains are partitioned according to their phylogenetic groupings. Our study reveals the existence of discrepancies between the mating behavior of a number of P. aurelia strains and their multilocus genetic profile, a controversial finding that has major consequences for both the current methods of species assignment and the species problem in the P. aurelia complex.
Michael Lynch - One of the best experts on this subject based on the ideXlab platform.
-
the rab7 subfamily across Paramecium aurelia species evidence of high conservation in sequence and function
Small GTPases, 2018Co-Authors: Lydia J Bright, Michael LynchAbstract:We examined sequence conservation and signatures of selection in Rab7 proteins across 11 Paramecium aurelia species, and determined the localization patterns of two P. tetraurelia Rab7 paralogs whe...
-
limited mutation rate variation within the Paramecium aurelia species complex
G3: Genes Genomes Genetics, 2018Co-Authors: Hongan Long, Thomas G Doak, Michael LynchAbstract:Mutation is one of the most fundamental evolutionary forces. Studying variation in the mutation rate within and among closely-related species can help reveal mechanisms of genome divergence, but such variation is unstudied in the vast majority of organisms. Previous studies on ciliated protozoa have found extremely low mutation rates. In this study, using mutation-accumulation techniques combined with deep whole-genome sequencing, we explore the germline base-substitution mutation-rate variation of three cryptic species in the Paramecium aurelia species complex—P. biaurelia, P. sexaurelia, and P. tetraurelia. We find that there is extremely limited variation of the mutation rate and spectrum in the three species and confirm the extremely low mutation rate of ciliates.
-
genetic diversity in the Paramecium aurelia species complex
Molecular Biology and Evolution, 2009Co-Authors: Francesco Catania, Ewa Przyboś, Alexey Potekhin, Francois Wurmser, Michael LynchAbstract:Current understanding of the population genetics of free-living unicellular eukaryotes is limited, and the amount of genetic variability in these organisms is still a matter of debate. We characterized—reproductively and genetically—worldwide samples of multiple Paramecium species belonging to a cryptic species complex, Paramecium aurelia, whose species have been shown to be reproductively isolated. We found that levels of genetic diversity both in the nucleus and in the mitochondrion are substantial within groups of reproductively compatible P. aurelia strains but drop considerably when strains are partitioned according to their phylogenetic groupings. Our study reveals the existence of discrepancies between the mating behavior of a number of P. aurelia strains and their multilocus genetic profile, a controversial finding that has major consequences for both the current methods of species assignment and the species problem in the P. aurelia complex.
Alexey Potekhin - One of the best experts on this subject based on the ideXlab platform.
-
Species of the Paramecium aurelia complex in Russia: new stands and overall distribution.
Folia Biologica, 2009Co-Authors: Alexey Potekhin, Ewa Przyboś, Irina Nekrasova, Varvara V. Yashchenko, Maria RautianAbstract:New stands of Paramecium biaurelia, P. triaurelia, P. tetraurelia, P. pentaurelia, P. novaurelia, and P. dodecaurelia were recorded in Russia. Especially interesting is the record of P. novaurelia in Vladivostok, Russian Far East, as it is a very rare species outside of Europe. The distribution of species of the Paramecium aurelia complex in Eurasia with emphasis on findings in Russia is discussed.
-
genetic diversity in the Paramecium aurelia species complex
Molecular Biology and Evolution, 2009Co-Authors: Francesco Catania, Ewa Przyboś, Alexey Potekhin, Francois Wurmser, Michael LynchAbstract:Current understanding of the population genetics of free-living unicellular eukaryotes is limited, and the amount of genetic variability in these organisms is still a matter of debate. We characterized—reproductively and genetically—worldwide samples of multiple Paramecium species belonging to a cryptic species complex, Paramecium aurelia, whose species have been shown to be reproductively isolated. We found that levels of genetic diversity both in the nucleus and in the mitochondrion are substantial within groups of reproductively compatible P. aurelia strains but drop considerably when strains are partitioned according to their phylogenetic groupings. Our study reveals the existence of discrepancies between the mating behavior of a number of P. aurelia strains and their multilocus genetic profile, a controversial finding that has major consequences for both the current methods of species assignment and the species problem in the P. aurelia complex.
-
Species of the Paramecium aurelia complex in Russia, Lower Volga Basin
2005Co-Authors: Ewa Przybok, Maria Rautian, Alexey PotekhinAbstract:Summary The Lower Volga Basin is very rich in species of the Paramecium aurelia complex. The presence of the following species has been revealed there: P. primaurelia, P. biaurelia, P. triaurelia, P. pentaurelia, P. sexaurelia, P. septaurelia, and P. novaurelia. P. septaurelia was recorded in the Volga Basin for the first time in Europe (Przybos et al., 2004); P. pentaurelia and P. sexaurelia are rare in Europe. In some sampling places several (up to four in one sample) species can occur in one and the same population*. Special attention is devoted to the frequent occurrence of P. septaurelia in the region of investigation. The idea of Schewiakoff (1893) about the role of birds' and other animals' migrations in dispersal of ciliates is discussed in the context of the data obtained.
Annette W Coleman - One of the best experts on this subject based on the ideXlab platform.
-
Paramecium aurelia revisited
Journal of Eukaryotic Microbiology, 2005Co-Authors: Annette W ColemanAbstract:The species Paramecium aurelia sensu latu, containing 15 sexually isolated subspecies (syngens), is the classic example of a sibling species complex in the ciliates. Using DNA sequence comparison, it is now possible to see whether this example parallels other studied sibling species complexes. We sequenced the internal transcribed spacer (ITS) region of the nuclear ribosomal cistron for 13 of the syngens plus two other Paramecium species and several Tetrahymena spp. Using available spirotrich sequences of the internal transcribed spacer 2 (ITS2), we established the RNA transcript folding pattern for ciliates. Ciliates exhibit the two highly conserved helices in their RNA transcript folding pattern in common with other eukaryotes, despite their unusual nuclear behavior and their presumed low copy number of micronuclear ribosomal repeats. Consequently, the set of 111-116 ITS2 nucleotide positions that are relatively conserved in evolution can be derived and used for comparative analysis. Mating behavior (i.e. gamete agglutination and fusion) is the character showing greatest correlation with the degree of ITS2 evolution in the P. aurelia complex, as also found in other eukaryotes. The degree of change in the ITS2 relatively conserved sequences found among the sibling species of P. aurelia is the same degree as found among the sibling species of the Drosophila melanogaster-mauritania-sechellia-simulans-yakuba species complex. The relatively conserved subregion of ITS2, determined from transcript secondary structure, is a tool for identifying the level of the biological species in the absence of knowledge of sexual compatibility in both micro- and macro-eukaryote species complexes.
Maria Rautian - One of the best experts on this subject based on the ideXlab platform.
-
New stands of species of the Paramecium aurelia complex in Africa and Europe.
Folia biologica, 2014Co-Authors: Maria Rautian, Ewa Przyboś, Marta Surmacz, Natalia LebedevaAbstract:The relevance of geographical distribution and the roles of dispersal and spatial isolation during the speciation of microorganisms are nowadays of great interest. The Paramecium aurelia species complex is a perfect model system to explore these questions given its long history as a study subject and broad distribution. However, the world-wide distribution of the Paramecium aurelia complex (Ciliophora, Protista) still needs study, e.g., sampling in the southern hemisphere has been quite limited, while Europe has been investigated for years, with the majority of aurelia species isolated from here. Recently, new stands of species of the P. aurelia complex were found in southern Europe (Malta, Bulgaria, Cyprus) and in the Czech Republic (P. primaurelia, P. triaurelia, P. octaurelia). In Africa (Republic of South Africa), new stands of P. primaurelia, P. triaurelia, and P. octaurelia were found. Interestingly, the rare species P. triaurelia, and P. octaurelia were found to co-occur both in South Africa (SA 13) and the Czech Republic (CKV 8). Newly established strains were identified to species by crossing with the test strains (the reference strains for the particular species).
-
New stands of species of the Paramecium aurelia complex (Ciliophora, Protozoa) in the Mediterranean region (Italy, Greece, Morocco).
Folia Biologica, 2012Co-Authors: Ewa Przyboś, Maria RautianAbstract:New stands of species of the Paramecium aurelia complex are presented in the paper, P. primaurelia recorded in Italy (Pisa) and in Morocco (Marrakesh), P. biaurelia in Italy (Calabria), P. triaurelia in Morocco (Ifrane), P. pentaurelia in Greece (Kastorya), and P. dodecaurelia in Italy (Padua).
-
Species of the Paramecium aurelia complex in Russia: new stands and overall distribution.
Folia Biologica, 2009Co-Authors: Alexey Potekhin, Ewa Przyboś, Irina Nekrasova, Varvara V. Yashchenko, Maria RautianAbstract:New stands of Paramecium biaurelia, P. triaurelia, P. tetraurelia, P. pentaurelia, P. novaurelia, and P. dodecaurelia were recorded in Russia. Especially interesting is the record of P. novaurelia in Vladivostok, Russian Far East, as it is a very rare species outside of Europe. The distribution of species of the Paramecium aurelia complex in Eurasia with emphasis on findings in Russia is discussed.
-
Species of the Paramecium aurelia complex in Russia, Lower Volga Basin
2005Co-Authors: Ewa Przybok, Maria Rautian, Alexey PotekhinAbstract:Summary The Lower Volga Basin is very rich in species of the Paramecium aurelia complex. The presence of the following species has been revealed there: P. primaurelia, P. biaurelia, P. triaurelia, P. pentaurelia, P. sexaurelia, P. septaurelia, and P. novaurelia. P. septaurelia was recorded in the Volga Basin for the first time in Europe (Przybos et al., 2004); P. pentaurelia and P. sexaurelia are rare in Europe. In some sampling places several (up to four in one sample) species can occur in one and the same population*. Special attention is devoted to the frequent occurrence of P. septaurelia in the region of investigation. The idea of Schewiakoff (1893) about the role of birds' and other animals' migrations in dispersal of ciliates is discussed in the context of the data obtained.
