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Marta Riutort - One of the best experts on this subject based on the ideXlab platform.
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The taxonomic status of Dugesiabiblica from Israel and Turkey (Platyhelminthes, Tricladida, Dugesiidae).
ZooKeys, 2015Co-Authors: Eduard Solà, Ronald Sluys, Ori Segev, Leon Blaustein, Marta RiutortAbstract:The taxonomic status of Dugesia biblica (Platyhelminthes, Tricladida, Dugesiidae) from Israel and Turkey is problematic due to its morphological similarity with Dugesia sicula since these nominal species present overlapping characters. In this study we analyzed histological preparations of specimens of these two nominal species and also compared mitochondrial COI gene sequences from Israeli populations to the already known haplotype composition of Dugesia sicula. We concluded that these animals belong to the same species and therefore we consider Dugesia biblica to be a junior synonym of Dugesia sicula. This implies that the distribution range of Dugesia sicula is even wider than previously thought, and that the species is present all around the Mediterranean Basin and on many of its islands.
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Evolutionary Analysis of Mitogenomes from Parasitic and Free-Living Flatworms
PloS one, 2015Co-Authors: Eduard Solà, Marta Álvarez-presas, Cristina Frías-lópez, Julio Rozas, D. Timothy J. Littlewood, Marta RiutortAbstract:Mitochondrial genomes (mitogenomes) are useful and relatively accessible sources of molecular data to explore and understand the evolutionary history and relationships of eukaryotic organisms across diverse taxonomic levels. The availability of complete mitogenomes from Platyhelminthes is limited; of the 40 or so published most are from parasitic flatworms (Neodermata). Here, we present the mitogenomes of two free-living flatworms (Tricladida): the complete genome of the freshwater species Crenobia alpina (Planariidae) and a nearly complete genome of the land planarian Obama sp. (Geoplanidae). Moreover, we have reanotated the published mitogenome of the species Dugesia japonica (Dugesiidae). This contribution almost doubles the total number of mtDNAs published for Tricladida, a species-rich group including model organisms and economically important invasive species. We took the opportunity to conduct comparative mitogenomic analyses between available free-living and selected parasitic flatworms in order to gain insights into the putative effect of life cycle on nucleotide composition through mutation and natural selection. Unexpectedly, we did not find any molecular hallmark of a selective relaxation in mitogenomes of parasitic flatworms; on the contrary, three out of the four studied free-living triclad mitogenomes exhibit higher A+T content and selective relaxation levels. Additionally, we provide new and valuable molecular data to develop markers for future phylogenetic studies on planariids and geoplanids.
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sAT and sGC values of the protein coding genes (PCG) along the mtDNA molecule.
2015Co-Authors: Eduard Solà, Marta Álvarez-presas, Cristina Frías-lópez, Timothy D. J. Littlewood, Julio Rozas, Marta RiutortAbstract:A) sAT of Tricladida; B) sAT of Neodermata; C) sGC of Tricladida; D) sGC of Neodermata.
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Phylogenetic schemes indicating the relationships of groups for which mitogenomes are available.
2015Co-Authors: Eduard Solà, Marta Álvarez-presas, Cristina Frías-lópez, Timothy D. J. Littlewood, Julio Rozas, Marta RiutortAbstract:A) Phylogeny of the Platyhelminthes according to Riutort et al., 2012 ([9]) and B) phylogeny of the Tricladida according to Riutort et al., 2012 and Sluys et al., 2013 ([52]). Monogenea, Trematoda and Cestoda constitute the Neodermata (parasitic flatworms) group. Grey circles indicate those groups for which mitogenomes are already available. Black circles indicate new obtained mitogenomes.
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The taxonomic status of Dugesia biblica from Israel and Turkey (Platyhelminthes, Tricladida, Dugesiidae)
Pensoft Publishers, 2015Co-Authors: Eduard Solà, Ronald Sluys, Ori Segev, Leon Blaustein, Marta RiutortAbstract:The taxonomic status of Dugesia biblica (Platyhelminthes, Tricladida, Dugesiidae) from Israel and Turkey is problematic due to its morphological similarity with D. sicula since these nominal species present overlapping characters. In this study we analyzed histological preparations of specimens of these two nominal species and also compared mitochondrial COI gene sequences from Israeli populations to the already known haplotype composition of D. sicula. We concluded that these animals belong to the same species and therefore we consider D. biblica to be a junior synonym of D. sicula. This implies that the distribution range of D. sicula is even wider than previously thought, and that the species is present all around the Mediterranean Basin and on many of its islands
Eduard Solà - One of the best experts on this subject based on the ideXlab platform.
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The taxonomic status of Dugesiabiblica from Israel and Turkey (Platyhelminthes, Tricladida, Dugesiidae).
ZooKeys, 2015Co-Authors: Eduard Solà, Ronald Sluys, Ori Segev, Leon Blaustein, Marta RiutortAbstract:The taxonomic status of Dugesia biblica (Platyhelminthes, Tricladida, Dugesiidae) from Israel and Turkey is problematic due to its morphological similarity with Dugesia sicula since these nominal species present overlapping characters. In this study we analyzed histological preparations of specimens of these two nominal species and also compared mitochondrial COI gene sequences from Israeli populations to the already known haplotype composition of Dugesia sicula. We concluded that these animals belong to the same species and therefore we consider Dugesia biblica to be a junior synonym of Dugesia sicula. This implies that the distribution range of Dugesia sicula is even wider than previously thought, and that the species is present all around the Mediterranean Basin and on many of its islands.
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Evolutionary Analysis of Mitogenomes from Parasitic and Free-Living Flatworms
PloS one, 2015Co-Authors: Eduard Solà, Marta Álvarez-presas, Cristina Frías-lópez, Julio Rozas, D. Timothy J. Littlewood, Marta RiutortAbstract:Mitochondrial genomes (mitogenomes) are useful and relatively accessible sources of molecular data to explore and understand the evolutionary history and relationships of eukaryotic organisms across diverse taxonomic levels. The availability of complete mitogenomes from Platyhelminthes is limited; of the 40 or so published most are from parasitic flatworms (Neodermata). Here, we present the mitogenomes of two free-living flatworms (Tricladida): the complete genome of the freshwater species Crenobia alpina (Planariidae) and a nearly complete genome of the land planarian Obama sp. (Geoplanidae). Moreover, we have reanotated the published mitogenome of the species Dugesia japonica (Dugesiidae). This contribution almost doubles the total number of mtDNAs published for Tricladida, a species-rich group including model organisms and economically important invasive species. We took the opportunity to conduct comparative mitogenomic analyses between available free-living and selected parasitic flatworms in order to gain insights into the putative effect of life cycle on nucleotide composition through mutation and natural selection. Unexpectedly, we did not find any molecular hallmark of a selective relaxation in mitogenomes of parasitic flatworms; on the contrary, three out of the four studied free-living triclad mitogenomes exhibit higher A+T content and selective relaxation levels. Additionally, we provide new and valuable molecular data to develop markers for future phylogenetic studies on planariids and geoplanids.
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sAT and sGC values of the protein coding genes (PCG) along the mtDNA molecule.
2015Co-Authors: Eduard Solà, Marta Álvarez-presas, Cristina Frías-lópez, Timothy D. J. Littlewood, Julio Rozas, Marta RiutortAbstract:A) sAT of Tricladida; B) sAT of Neodermata; C) sGC of Tricladida; D) sGC of Neodermata.
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Phylogenetic schemes indicating the relationships of groups for which mitogenomes are available.
2015Co-Authors: Eduard Solà, Marta Álvarez-presas, Cristina Frías-lópez, Timothy D. J. Littlewood, Julio Rozas, Marta RiutortAbstract:A) Phylogeny of the Platyhelminthes according to Riutort et al., 2012 ([9]) and B) phylogeny of the Tricladida according to Riutort et al., 2012 and Sluys et al., 2013 ([52]). Monogenea, Trematoda and Cestoda constitute the Neodermata (parasitic flatworms) group. Grey circles indicate those groups for which mitogenomes are already available. Black circles indicate new obtained mitogenomes.
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The taxonomic status of Dugesia biblica from Israel and Turkey (Platyhelminthes, Tricladida, Dugesiidae)
Pensoft Publishers, 2015Co-Authors: Eduard Solà, Ronald Sluys, Ori Segev, Leon Blaustein, Marta RiutortAbstract:The taxonomic status of Dugesia biblica (Platyhelminthes, Tricladida, Dugesiidae) from Israel and Turkey is problematic due to its morphological similarity with D. sicula since these nominal species present overlapping characters. In this study we analyzed histological preparations of specimens of these two nominal species and also compared mitochondrial COI gene sequences from Israeli populations to the already known haplotype composition of D. sicula. We concluded that these animals belong to the same species and therefore we consider D. biblica to be a junior synonym of D. sicula. This implies that the distribution range of D. sicula is even wider than previously thought, and that the species is present all around the Mediterranean Basin and on many of its islands
Kazuya Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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a comprehensive comparison of sex inducing activity in asexual worms of the planarian dugesia ryukyuensis the crucial sex inducing substance appears to be present in yolk glands in Tricladida
Zoological letters, 2018Co-Authors: Haruka Nakagawa, Kiyono Sekii, Takanobu Maezawa, Makoto Kitamura, Soichiro Miyashita, Marina Abukawa, Midori Matsumoto, Kazuya KobayashiAbstract:Turbellarian species can post-embryonically produce germ line cells from pluripotent stem cells called neoblasts, which enables some of them to switch between an asexual and a sexual state in response to environmental changes. Certain low-molecular-weight compounds contained in sexually mature animals act as sex-inducing substances that trigger post-embryonic germ cell development in asexual worms of the freshwater planarian Dugesia ryukyuensis (Tricladida). These sex-inducing substances may provide clues to the molecular mechanism of this reproductive switch. However, limited information about these sex-inducing substances is available. Our assay system based on feeding sex-inducing substances to asexual worms of D. ryukyuensis is useful for evaluating sex-inducing activity. We used the freshwater planarians D. ryukyuensis and Bdellocephala brunnea (Tricladida), land planarian Bipalium nobile (Tricladida), and marine flatworm Thysanozoon brocchii (Polycladida) as sources of the sex-inducing substances. Using an assay system, we showed that the three Tricladida species had sufficient sex-inducing activity to fully induce hermaphroditic reproductive organs in asexual worms of D. ryukyuensis. However, the sex-inducing activity of T. brocchii was sufficient only to induce a pair of ovaries. We found that yolk glands, which are found in Tricladida but not Polycladida, may contain the sex-inducing substance that can fully sexualize asexual worms of D. ryukyuensis. Our results suggest that within Tricladida, there are one or more common compounds or functional analogs capable of fully sexualizing asexual worms of D. ryukyuensis; namely, the crucial sex-inducing substance (hydrophilic and heat-stable, but not a peptide) produced in yolk glands.
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A comprehensive comparison of sex-inducing activity in asexual worms of the planarian Dugesia ryukyuensis: the crucial sex-inducing substance appears to be present in yolk glands in Tricladida
Zoological Letters, 2018Co-Authors: Haruka Nakagawa, Kiyono Sekii, Takanobu Maezawa, Makoto Kitamura, Soichiro Miyashita, Marina Abukawa, Midori Matsumoto, Kazuya KobayashiAbstract:Background Turbellarian species can post-embryonically produce germ line cells from pluripotent stem cells called neoblasts, which enables some of them to switch between an asexual and a sexual state in response to environmental changes. Certain low-molecular-weight compounds contained in sexually mature animals act as sex-inducing substances that trigger post-embryonic germ cell development in asexual worms of the freshwater planarian Dugesia ryukyuensis (Tricladida). These sex-inducing substances may provide clues to the molecular mechanism of this reproductive switch. However, limited information about these sex-inducing substances is available. Results Our assay system based on feeding sex-inducing substances to asexual worms of D. ryukyuensis is useful for evaluating sex-inducing activity. We used the freshwater planarians D. ryukyuensis and Bdellocephala brunnea (Tricladida), land planarian Bipalium nobile (Tricladida), and marine flatworm Thysanozoon brocchii (Polycladida) as sources of the sex-inducing substances. Using an assay system, we showed that the three Tricladida species had sufficient sex-inducing activity to fully induce hermaphroditic reproductive organs in asexual worms of D. ryukyuensis . However, the sex-inducing activity of T. brocchii was sufficient only to induce a pair of ovaries. We found that yolk glands, which are found in Tricladida but not Polycladida, may contain the sex-inducing substance that can fully sexualize asexual worms of D. ryukyuensis . Conclusions Our results suggest that within Tricladida, there are one or more common compounds or functional analogs capable of fully sexualizing asexual worms of D. ryukyuensis ; namely, the crucial sex-inducing substance (hydrophilic and heat-stable, but not a peptide) produced in yolk glands.
Klaus Rohde - One of the best experts on this subject based on the ideXlab platform.
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A Molecular Test of Platyhelminth Phylogeny: Inferences from Partial 28S rDNA Sequences
Invertebrate Biology, 1999Co-Authors: Marianne K Litvaitis, Klaus RohdeAbstract:Nucleotide sequences of the region extending from the D3 to the D6 expansion segments of the 28S rDNA gene were used to reconstruct evolutionary relationships within the Platyhelminthes. Neighbor-joining and parsimony analyses of representatives of most major platyhelminth taxa revealed a basal Catenulida, a monophyletic Acoelomorpha, a sister-group relationship of Macrostomorpha and Polycladida (59% of bootstrap replications), and monophyletic Tricladida. We found no evidence of a taxon Seriata (p=.0001); however, the paraphyletic status of the Proseriata needs further investigation. Although Neodermata appeared as a monophyletic group, Monogenea was paraphyletic (p
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Aspects of the phylogeny of Platyhelminthes based on 18S ribosomal DNA and protonephridial ultrastructure
Biology of Turbellaria and some Related Flatworms, 1995Co-Authors: Klaus Rohde, Peter R Baverstock, Alan M. Johnson, N. A. WatsonAbstract:DNA studies of 23 taxa (20 platyhelminths, 1 nemertean, Homo and Artemia) and electron-microscopic studies of the protonephridia of many platyhelminths (supported by some additional ultrastructural data) have led to the following conclusions: the Neodermata are monophyletic; Temnocephalida and Dalyelliida form one clade and are not the ‘primitive’ sister group of the Neodermata; Gyrocotylidea, Amphilinidea and Eucestoda form one monophylum; Pterastericolidae and Umagillidae are dalyelliids and not the sister group of the Neodermata; and Proseriata are unlikely to be closely related with the Tricladida. A large taxon consisting of the Proseriata and some other ‘turbellarians’ may represent the sister group of the Neodermata.
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Contributions to the phylogeny of platyhelminthes based on partial sequencing of 18S ribosomal DNA
International journal for parasitology, 1993Co-Authors: Klaus Rohde, Peter R Baverstock, N. A. Watson, Alan M. Johnson, Chris Hefford, John Ellis, Sabine DittmannAbstract:Partial sequencing of the 18S ribosomal DNA gene of one nemertean and 13 free-living and parasitic Platyhelminthes (556 nucleotides), and of one nemertean and 20 Platyhelminthes (556 nucleotides) was used to test several hypotheses concerning the phylogenetic relationships of Platyhelminthes. The following conclusions were reached: the Neodermata is monophyletic; Trematoda (Aspidogastrea and Digenea) is monophyletic, although a sister group relationship of the Aspidogastrea and all other Neodermata cannot be definitely ruled out; the Cestoda comprising the Eucestoda, Amphilinidea and Gyrocotylidea is monophyletic; it is unresolved whether the Monogenea is paraphyletic; neither Gyrocotylidea and Monopisthocotylea nor Gyrocotylidea and Monogenea as a whole are sister groups; Anoplodiscus is a monopisthocotylean monogenean; none of Proseriata, Pterastericolidae/Umagillidae, Kalyptorhynchia, Rhabdocoela as a whole, Dalyelliida or the Temnocephalidae is the sister group of the Neodermata; there is some evidence that a larger taxon consisting of Proseriata, Tricladida and Rhabdocoela may be the sister group of the Neodermata but definitive evidence for a sister group relationship between the Neodermata and any turbellarian taxon is lacking; Rhabdocoela and Lecithoepitheliata are not closely related; it is unresolved whether the Rhabdocoela is monophyletic; Umagillidae, Pterastericolidae and Temnocephalidae belong to one monophylum; the Temnocephalidae are very close to the dalyelliids; Tricladida and Rhabdocoela are sister groups, the exact position of the Catenulida and Nemertini in relation to the Platyhelminthes has not been resolved, although Catenulida and Lecithoepitheliata may belong to one clade.
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Ultrastructure of Sperm and Spermatogenesis of Artioposthia Sp (Platyhelminthes, Tricladida, Terricola)
Australian Journal of Zoology, 1992Co-Authors: Li Minmin, N. A. Watson, Klaus RohdeAbstract:This is the first reported study of the ultrastructure of sperm and spermatogenesis of a terrestrial triclad (Terricola). Processes from the cells of the testis wall envelop early germinal cells, and wall cells are ciliated in the transition zone to the sperm duct. Following meiosis of spermatocytes, spermatids develop by formation of a zone of differentiation containing peripheral microtubules, two centrioles facing in opposite directions, a prominent intercentriolar body and a semicircle of dense material around the centrioles. Centrioles become basal bodies giving rise to free flagella. Elongation of this zone, accompanied by rotation of the basal bodies around the shaft, results in flagella being carried to a distal and subterminal location, emerging on the one side of, and perpendicular to, the spermatid shaft. Nucleus and mitochondrion migrate into the shaft. Artioposthia is compared with other triclads and other turbellarian groups. The lack of dense bodies in sperm and of rootlets during spermiogenesis may be autapomorphies for the Tricladida. To our knowledge, the only report of splitting of flagellar tips into a number of separate threads, outside Tricladida, is from Syndisyrinx punicea (Rhabdocoela: Umagillidae) (Rohde and Watson 1988).
Salvador Carranza - One of the best experts on this subject based on the ideXlab platform.
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morphological
2014Co-Authors: Salvador Carranza, Iñaki Ruiz-trillo, D. Timothy, J. Littlewood, Karen A. Clough, Jaume Bagun A, Marta RiutortAbstract:A robust molecular phylogeny of the Tricladida (Platyhelminthes: Seriata) with a discussion o
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A robust molecular phylogeny of the Tricladida (Platyhelminthes: Seriata) with a discussion on morphological synapomorphies
Proceedings of The Royal Society B: Biological Sciences, 1998Co-Authors: Salvador Carranza, D. T. J. Littlewood, K. A. Clough, Iñaki Ruiz-trillo, Jaume Baguñà, Marta RiutortAbstract:The suborder Tricladida (Platyhelminthes: Turbellaria, Seriata) comprises most well–known species of free–living flatworms. Four infraorders are recognized: (i) the Maricola (marine planarians); (ii) the Cavernicola (a group of primarily cavernicolan planarians); (iii) the Paludicola (freshwater planarians); and (iv) the Terricola (land planarians). The phylogenetic relationships among these infraorders have been analysed using morphological characters, but they remain uncertain. Here we analyse the phylogeny and classification of the Tricladida, with additional, independent, molecular data from complete sequences of 18S rDNA and 18S rRNA. We use maximum parsimony and neighbour–joining methods and the characterization of a unique gene duplication event involving the Terricola and the dugesiids to reconstruct the phylogeny. The results show that the Maricola is monophyletic and is the primitive sister group to the rest of the Tricladida (the Paludicola plus the Terricola). The Paludicola are paraphyletic since the Terricola and one paludicolan family, the Dugesiidae, share a more recent common ancestor than the dugesiids with other paludicolans (dendrocoelids and planariids). A reassessment of morphological evidence may confirm the apparent redundancy of the existing infraorders Paludicola and Terricola. In the meantime, we suggest replacing the Paludicola and Terricola with a new clade, the Continenticola, which comprises the families Dugesiidae, Planariidae, Dendrocoelidae and the Terricola.
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a reappraisal of the phylogenetic and taxonomic position of land planarians platyhelminthes turbellaria Tricladida inferred from 18s rdna sequence s
Pedobiologia, 1998Co-Authors: Salvador Carranza, Marta Riutort, D. T. J. Littlewood, Inaki Ruiztrillo, Jaume BaguñàAbstract:Land planarians belong to the suborder Tricladida within which four infraorders are currently recognized: the Maricola, the Cavernicola, the Paludicola and the Terricola (land planarians). Phylogenetic analyses using morphological characters support the monophyly of all infraorders with the Maricola as the primitive sister group to the rest of the Tricladida, and Terricola and Paludicola being derived sister groups. In view of the biological importance of land planarians, a robust phylogenetic scheme of the Tricladida is required for both taxonomy and comparative purposes. Using nucleotide-sequence data of the 18S ribosomal genes it has recently been reported that the Terricola and a family of the Paludicola, the Dugesiidae, share an 18S gene duplication (types I and II) that can be explained only by accepting a common origin for the Terricola+Dugesiidae (Carranza et al. 1998). In addition, both distance and maximum parsimony analyses also support that Terricola and Dugesiidae form a monophyletic group. Here, we extend our analysis up to 18 species of paludicolans and 11 species of terricolans. Distance-based and maximum-likelihood analyses resulted in phylogenetic trees strongly supporting the Terricola and the Dugesiidae as forming a monophyletic group, though the internal phylogeny of each clade remains unresolved. These results strongly supports that landplanarians derive from freshwater ancestors and, therefore, that its taxonomic rank and position within the Tricladida has to be reconsidered.
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Isolation and characterization of microsatellite loci from the planarian Dugesia polychroa (Schmidt) (Platyhelminthes: Tricladida)
Molecular Ecology, 1997Co-Authors: S. Ramachandran, Letizia Gerace, N. Pavlovic, Salvador Carranza, Leo W Beukeboom, Nicolaas Karel MichielsAbstract:The genomes of many species have been shown to contain loci composed of tandemly repeated short DNA sequences known as microsatellites or simple sequence motifs (Tautz & Renz 1984). Allelic variation in copy number of the repeat unit renders these loci polymorphic, making them convenient markers for evolutionary studies, including the analysis of population structure (Bruford & Wayne 1993; Schlotterer & Pemberton 1994), mating systems and paternity (Queller et al. 1993). We developed microsatellite markers for the free-living fresh water planarian Dugesia polychroa (Platyhelminthes: Tricladida) to study the population structure and mating system of these simultaneously hermaphroditic worms characterized by internal fertilization. Dugesia polychroa has two reproductive biotypes, sexual diploids and pseudogamous parthenogens, which
