Building on the strength of the present cold neutron three-axis spectrometer IN14, but using stat... more Building on the strength of the present cold neutron three-axis spectrometer IN14, but using state-of-the-art neutron optics, we conceived the next generation three-axis instrument for low energy spectroscopy (ThALES) at the Institut Laue-Langevin (ILL). The main aims of the new instrument are: (i) to increase the overall data collection rate by rebuilding the neutron optics of the primary spectrometer achieving a higher incident neutron flux as well as by multiplexing the analyser-detector system, (ii) to provide an efficient and easy-to-use polarized neutron option, (iii) to extend the incident neutron range towards higher energies bridging the gap with thermal instruments, and (iv) to be able to use high-field magnets---such as the currently available 15 T cryomagnet---under all possible experimental conditions, i.e. in a wider range of incident energies. The expected increase in count rate by at least one order of magnitude allows for new experiments such as high pressure experiments on small sample sizes or investigations of magnetic excitations in thin films. Polarized inelastic neutron measurements should equal count rates of the present IN14 in unpolarized mode. The implementation of various optical elements enhances the flexibility of the instrument and allows trading momentum resolution for high neutron intensity.
We propose a new classification of Parabasalia which is congruent with both ultrastructural and m... more We propose a new classification of Parabasalia which is congruent with both ultrastructural and molecular-phylogenetic studies. We identify six main parabasalid lineages and give them the rank of class: Hypotrichomonadea, Trichomonadea, Tritrichomonadea, Cristamonadea, Trichonymphea, and Spirotrichonymphea. Trichomonadea is characterized by a single mastigont and by the absence of both a comb-like structure and an infrakinetosomal body. Most representatives also possess a lamelliform undulating membrane. Trichomonadea is divided into two monophyletic orders, Trichomonadida (family Trichomonadidae; with a B-type costa) and Honigbergiellida (families Honigbergiellidae, Hexamastigidae and Tricercomitidae; without a costa). The class Tritrichomonadea, with a single order Tritrichomonadida, is ancestrally characterized by a single mastigont with four flagella, and both a comb-like structure and an infrakinetosomal body. The morphologically most complex representatives (family Tritrichomonadidae) possess in addition a rail-type undulating membrane, an A-type costa, and a suprakinetosomal body. These last three characters are absent in families Monocercomonadidae and Simplicimonadidae. The remaining tritrichomonadids, Dientamoebidae, have undergone reductive evolution. Cristamonads (Cristamonadea) are morphologically derived from tritrichomonads. Because we are unable to determine morphologically homogenous monophyletic lineages within cristamonads, we classify all cristamonads into a single family, Lophomonadidae. Hypotrichomonadea, comprising the genera Trichomitus and Hypotrichomonas, resembles Tritrichomonadea by an A-type costa, and by the presence of a comb-like structure in the mastigont. However, they do not possess an infrakinetosomal body, and are not specifically related to Tritrichomonadea in molecular-phylogenetic analyses. Moreover, unlike Tritrichomonadea, Hypotrichomonadea possesses a lamelliform undulating membrane. The remaining parabasalids are of complex morphology and belong to the classes Trichonymphea and Spirotrichonymphea. A new parabasalid genus, Simplicimonas (Tritrichomonadea), and three new species, Tetratrichomonas undula, Hexamastix coercens and Simplicimonas similis, are described.
Circumscribing major eukaryote groups and resolving higher order relationships between them are a... more Circumscribing major eukaryote groups and resolving higher order relationships between them are among the most chal- lenging tasks facing molecular evolutionists. Recently, evidence suggesting a new supergroup (the Excavata) comprising a wide array of flagellates has been collected. This group consists of diplomonads, retortamonads, Carpediemonas, heteroloboseans, Trimastix, jakobids, and Malawimonas, all of which possess a particular type of ventral feeding
We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from... more We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from amphibian, reptilian, mammalian hosts, and from a slug with the aid of protargol staining and analyses of ITS1-5.8S rRNA-ITS2, SSU rRNA, and α-tubulin gene sequences. The phylogenetic tree based on the concatenate of all sequences showed the monophyly of the genus Tetratrichomonas with respect to the genus Trichomonas.
The main function of the hydrogenosome, a typical organelle of trichomonads, is to convert malate... more The main function of the hydrogenosome, a typical organelle of trichomonads, is to convert malate or pyruvate to H2 ,C O 2 and acetate by a pathway associated with ATP synthesis. This pathway relies on activity of iron-sulfur proteins such as pyruvate:ferredoxin oxidoreductase (PFOR), hydrogenase and ferredoxin. To examine the effect of iron availability on proper hydrogenosomal function, the metabolic
We present the first molecular phylogenetic examination of the evolutionary position of retortamo... more We present the first molecular phylogenetic examination of the evolutionary position of retortamonads, a group of mitochondrion-lacking flagellates usually found as commensals of the intestinal tracts of vertebrates. Our phylogenies include small subunit ribosomal gene sequences from six retortamonad isolates-four from mammals and two from amphibians. All six sequences were highly similar (95%-99%), with those from mammals being almost identical to each other. All phylogenetic methods utilized unequivocally placed retortamonads with another amitochondriate group, the diplomonads. Surprisingly, all methods weakly supported a position for retortamonads cladistically within diplomonads, as the sister group to Giardia. This position would conflict with a single origin and uniform retention of the doubled-cell organization displayed by most diplomonads, but not by retortamonads. Diplomonad monophyly was not rejected by Shimodaira-Hasegawa, Kishino-Hasegawa, and expected likelihood weight...
We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from... more We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from amphibian, reptilian, mamma- lian hosts, and from a slug with the aid of protargol staining and analyses of ITS1-5.8S rRNA-ITS2, SSU rRNA, and -tubulin gene sequences. The phylogenetic tree based on the concatenate of all sequences showed the monophyly of the genus Tetratrichomonas with respect to the genus
Tetratrichomonas gallinarum is a widespread intestinal parasite of galliform and anseriform birds... more Tetratrichomonas gallinarum is a widespread intestinal parasite of galliform and anseriform birds. The pathogenicity of this species is controversial, presenting an unsettled problem as yet. We analysed the polymorphism and genetic relationship among 29 isolates of T. gallinarum obtained from eight bird species and five T. gallinarum-like isolates from the oral cavity and lower respiratory tract of human patients. Two methods were used for the analyses: RAPD and sequencing of 16S rRNA, 5.8S rRNA, ITS1 and ITS2 genes, both producing consistent and well-supported results. The isolates were divided into five groups, A–E, with eleven subgroups. The distance between groups E, D and the cluster A–B–C considerably exceeded usual intraspecific polymorphism seen in trichomonads. Moreover, the largest subgroup, A2 (containing 18 isolates), was divided into three branches according to the host specificity. All isolates from humans were placed into avian subgroups A2 and B2. We conclude that ou...
Building on the strength of the present cold neutron three-axis spectrometer IN14, but using stat... more Building on the strength of the present cold neutron three-axis spectrometer IN14, but using state-of-the-art neutron optics, we conceived the next generation three-axis instrument for low energy spectroscopy (ThALES) at the Institut Laue-Langevin (ILL). The main aims of the new instrument are: (i) to increase the overall data collection rate by rebuilding the neutron optics of the primary spectrometer achieving a higher incident neutron flux as well as by multiplexing the analyser-detector system, (ii) to provide an efficient and easy-to-use polarized neutron option, (iii) to extend the incident neutron range towards higher energies bridging the gap with thermal instruments, and (iv) to be able to use high-field magnets---such as the currently available 15 T cryomagnet---under all possible experimental conditions, i.e. in a wider range of incident energies. The expected increase in count rate by at least one order of magnitude allows for new experiments such as high pressure experiments on small sample sizes or investigations of magnetic excitations in thin films. Polarized inelastic neutron measurements should equal count rates of the present IN14 in unpolarized mode. The implementation of various optical elements enhances the flexibility of the instrument and allows trading momentum resolution for high neutron intensity.
We propose a new classification of Parabasalia which is congruent with both ultrastructural and m... more We propose a new classification of Parabasalia which is congruent with both ultrastructural and molecular-phylogenetic studies. We identify six main parabasalid lineages and give them the rank of class: Hypotrichomonadea, Trichomonadea, Tritrichomonadea, Cristamonadea, Trichonymphea, and Spirotrichonymphea. Trichomonadea is characterized by a single mastigont and by the absence of both a comb-like structure and an infrakinetosomal body. Most representatives also possess a lamelliform undulating membrane. Trichomonadea is divided into two monophyletic orders, Trichomonadida (family Trichomonadidae; with a B-type costa) and Honigbergiellida (families Honigbergiellidae, Hexamastigidae and Tricercomitidae; without a costa). The class Tritrichomonadea, with a single order Tritrichomonadida, is ancestrally characterized by a single mastigont with four flagella, and both a comb-like structure and an infrakinetosomal body. The morphologically most complex representatives (family Tritrichomonadidae) possess in addition a rail-type undulating membrane, an A-type costa, and a suprakinetosomal body. These last three characters are absent in families Monocercomonadidae and Simplicimonadidae. The remaining tritrichomonadids, Dientamoebidae, have undergone reductive evolution. Cristamonads (Cristamonadea) are morphologically derived from tritrichomonads. Because we are unable to determine morphologically homogenous monophyletic lineages within cristamonads, we classify all cristamonads into a single family, Lophomonadidae. Hypotrichomonadea, comprising the genera Trichomitus and Hypotrichomonas, resembles Tritrichomonadea by an A-type costa, and by the presence of a comb-like structure in the mastigont. However, they do not possess an infrakinetosomal body, and are not specifically related to Tritrichomonadea in molecular-phylogenetic analyses. Moreover, unlike Tritrichomonadea, Hypotrichomonadea possesses a lamelliform undulating membrane. The remaining parabasalids are of complex morphology and belong to the classes Trichonymphea and Spirotrichonymphea. A new parabasalid genus, Simplicimonas (Tritrichomonadea), and three new species, Tetratrichomonas undula, Hexamastix coercens and Simplicimonas similis, are described.
Circumscribing major eukaryote groups and resolving higher order relationships between them are a... more Circumscribing major eukaryote groups and resolving higher order relationships between them are among the most chal- lenging tasks facing molecular evolutionists. Recently, evidence suggesting a new supergroup (the Excavata) comprising a wide array of flagellates has been collected. This group consists of diplomonads, retortamonads, Carpediemonas, heteroloboseans, Trimastix, jakobids, and Malawimonas, all of which possess a particular type of ventral feeding
We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from... more We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from amphibian, reptilian, mammalian hosts, and from a slug with the aid of protargol staining and analyses of ITS1-5.8S rRNA-ITS2, SSU rRNA, and α-tubulin gene sequences. The phylogenetic tree based on the concatenate of all sequences showed the monophyly of the genus Tetratrichomonas with respect to the genus Trichomonas.
The main function of the hydrogenosome, a typical organelle of trichomonads, is to convert malate... more The main function of the hydrogenosome, a typical organelle of trichomonads, is to convert malate or pyruvate to H2 ,C O 2 and acetate by a pathway associated with ATP synthesis. This pathway relies on activity of iron-sulfur proteins such as pyruvate:ferredoxin oxidoreductase (PFOR), hydrogenase and ferredoxin. To examine the effect of iron availability on proper hydrogenosomal function, the metabolic
We present the first molecular phylogenetic examination of the evolutionary position of retortamo... more We present the first molecular phylogenetic examination of the evolutionary position of retortamonads, a group of mitochondrion-lacking flagellates usually found as commensals of the intestinal tracts of vertebrates. Our phylogenies include small subunit ribosomal gene sequences from six retortamonad isolates-four from mammals and two from amphibians. All six sequences were highly similar (95%-99%), with those from mammals being almost identical to each other. All phylogenetic methods utilized unequivocally placed retortamonads with another amitochondriate group, the diplomonads. Surprisingly, all methods weakly supported a position for retortamonads cladistically within diplomonads, as the sister group to Giardia. This position would conflict with a single origin and uniform retention of the doubled-cell organization displayed by most diplomonads, but not by retortamonads. Diplomonad monophyly was not rejected by Shimodaira-Hasegawa, Kishino-Hasegawa, and expected likelihood weight...
We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from... more We studied morphological and molecular polymorphism of 53 Tetratrichomonas isolates obtained from amphibian, reptilian, mamma- lian hosts, and from a slug with the aid of protargol staining and analyses of ITS1-5.8S rRNA-ITS2, SSU rRNA, and -tubulin gene sequences. The phylogenetic tree based on the concatenate of all sequences showed the monophyly of the genus Tetratrichomonas with respect to the genus
Tetratrichomonas gallinarum is a widespread intestinal parasite of galliform and anseriform birds... more Tetratrichomonas gallinarum is a widespread intestinal parasite of galliform and anseriform birds. The pathogenicity of this species is controversial, presenting an unsettled problem as yet. We analysed the polymorphism and genetic relationship among 29 isolates of T. gallinarum obtained from eight bird species and five T. gallinarum-like isolates from the oral cavity and lower respiratory tract of human patients. Two methods were used for the analyses: RAPD and sequencing of 16S rRNA, 5.8S rRNA, ITS1 and ITS2 genes, both producing consistent and well-supported results. The isolates were divided into five groups, A–E, with eleven subgroups. The distance between groups E, D and the cluster A–B–C considerably exceeded usual intraspecific polymorphism seen in trichomonads. Moreover, the largest subgroup, A2 (containing 18 isolates), was divided into three branches according to the host specificity. All isolates from humans were placed into avian subgroups A2 and B2. We conclude that ou...
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