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Marco Ferraguti - One of the best experts on this subject based on the ideXlab platform.
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alike but different the evolution of the Tubifex Tubifex species complex annelida clitellata through polyploidization
BMC Evolutionary Biology, 2014Co-Authors: Roberto Marotta, Angelica Crottini, Elena Raimondi, Cristina Fondello, Marco FerragutiAbstract:Background: Tubifex Tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. Tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. Results: The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. Tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. Conclusions: These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. Tubifex species complex.
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alike but different the evolution of the Tubifex Tubifex species complex annelida clitellata through polyploidization
BMC Evolutionary Biology, 2014Co-Authors: Roberto Marotta, Angelica Crottini, Elena Raimondi, Cristina Fondello, Marco FerragutiAbstract:Tubifex Tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. Tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. Tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. Tubifex species complex.
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a morphological reappraisal of Tubifex blanchardi vejdovský 1891 clitellata tubificidae
Acta Zoologica, 2009Co-Authors: Roberto Marotta, Angelica Crottini, Valeria Prada, Marco FerragutiAbstract:Tubifex blanchardi Vejdovský, 1891 is a freshwater tubificid, often living in sympatry with Tubifex Tubifex (Muller 1774). Although considered from its discovery as a species on its own, its biological status is debated. During the early seventies T. blanchardi was reduced to a mere form of T. Tubifex, as a particular case of polymorphism in chaetal pattern. Using classical histological techniques, microdissections of portions of the male genital apparatus and phalloidin staining of dissected copulatory organs we investigated 163 mixed individuals of T. blanchardi and T. Tubifex belonging to sympatric populations from the Lambro River (Milan, Northern Italy). The internal morphology of T. blanchardi is described for the first time. Our results show that T. Tubifex and T. blanchardi differ in several characters concerning both their external and internal morphology, and in the fine organization of their copulatory organs. Several independent character sets support the separation of T. blanchardi from T. Tubifex, suggesting that it is an independent species. This study also supports the idea that T. blanchardi and T. bergi (Hrabě, 1935), another species closely related to T. Tubifex, are not conspecific. The observed morphological differences between allopatric populations of T. Tubifex are discussed.
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the world in a river a preliminary analysis of the 16s rdna variability of Tubifex species clitellata tubificidae from the lambro river
Molecular Phylogenetics and Evolution, 2008Co-Authors: Angelica Crottini, Roberto Marotta, Michela Barbuto, Maurizio Casiraghi, Marco FerragutiAbstract:Tubifex Tubifex Muller, 1774 is a cosmopolitan freshwater tubificid widely used as a model in ecotoxicology, population dynamics and developmental biology. It is traditionally recognized as a polytypic species and in Lambro River (Milano, Northern Italy) it occurs in two of the three recognized forms, named "Tubifex" and "blanchardi", alternatively considered as ecological forms or distinct species. To investigate the genetic differentiation of the populations occurring in the Lambro River we sequenced a fragment of the 16S rDNA mitochondrial gene. T. blanchardi, characterized by a low genetic diversity, was genetically segregated from the other sympatric T. Tubifex. The ancestral state reconstruction was used to define the morphological traits that support its distinctness. On the contrary, the other T. Tubifex from the Lambro community, although morphologically indistinguishable, revealed an astonishing degree of genetic variability, both between and within the three identified clades that proved to be genetically isolated. Using samples from the mixed Lambro River community and from other countries around the world we present an overview of the species complex' 16S rDNA variability. Our results show that the genetic variability did not sensibly increase widening the data set, suggesting that the Lambro River populations meet the species' worldwide genetic variability.
Evaldo Luiz Gaeta Espindola - One of the best experts on this subject based on the ideXlab platform.
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acute toxicity of zinc and arsenic to the warmwater aquatic oligochaete branchiura sowerbyi as compared to its coldwater counterpart Tubifex Tubifex annelida clitellata
Journal of Soils and Sediments, 2016Co-Authors: Haroldo Lobo, Leire Mendezfernandez, Maite Martinezmadrid, Michiel A Daam, Evaldo Luiz Gaeta EspindolaAbstract:Purpose This study aimed at evaluating the acute effects of arsenic and zinc to the warmwater aquatic oligochaete Branchiura sowerbyi. Relative sensitivity with the coldwater species Tubifex Tubifex was compared. Implications for the use of B. sowerbyi in the risk assessment of sediments in the tropics are discussed.
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acute toxicity of zinc and arsenic to the warmwater aquatic oligochaete branchiura sowerbyi as compared to its coldwater counterpart Tubifex Tubifex annelida clitellata
Journal of Soils and Sediments, 2016Co-Authors: Haroldo Lobo, Leire Mendezfernandez, Maite Martinezmadrid, Michiel A Daam, Evaldo Luiz Gaeta EspindolaAbstract:This study aimed at evaluating the acute effects of arsenic and zinc to the warmwater aquatic oligochaete Branchiura sowerbyi. Relative sensitivity with the coldwater species Tubifex Tubifex was compared. Implications for the use of B. sowerbyi in the risk assessment of sediments in the tropics are discussed. Water-only (96 h) and sediment (14 days) toxicity tests were conducted with both species evaluating a concentration series of arsenic and zinc. The tests were conducted considering the environmental conditions in the natural habitat of T. Tubifex (predominantly temperate) and B. sowerbyi (predominantly tropical). Both lethal and sublethal endpoints (autotomy of the posterior body parts, abnormal behavior and appearance) were determined in the tests. The lethal (LC10 and LC50) and effect (EC10 and EC50) concentrations were also determined to assess metal sensitivity for both species. Both test species were more sensitive to Zn than As in water-only tests, which is in agreement with previous studies evaluating the toxicity of these metals to aquatic oligochaetes. Sublethal effects were generally noted at concentrations lower than those leading to mortality. The warmwater oligochaete B. sowerbyi was more sensitive to both metals tested than the coldwater species T. Tubifex. Study findings support the need for using indigenous tropical species in risk assessments in the tropics. In addition, sublethal effect parameters should be included in toxicity testing with aquatic oligochaetes.
Roberto Marotta - One of the best experts on this subject based on the ideXlab platform.
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alike but different the evolution of the Tubifex Tubifex species complex annelida clitellata through polyploidization
BMC Evolutionary Biology, 2014Co-Authors: Roberto Marotta, Angelica Crottini, Elena Raimondi, Cristina Fondello, Marco FerragutiAbstract:Background: Tubifex Tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. Tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. Results: The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. Tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. Conclusions: These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. Tubifex species complex.
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alike but different the evolution of the Tubifex Tubifex species complex annelida clitellata through polyploidization
BMC Evolutionary Biology, 2014Co-Authors: Roberto Marotta, Angelica Crottini, Elena Raimondi, Cristina Fondello, Marco FerragutiAbstract:Tubifex Tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. Tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. Tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. Tubifex species complex.
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a morphological reappraisal of Tubifex blanchardi vejdovský 1891 clitellata tubificidae
Acta Zoologica, 2009Co-Authors: Roberto Marotta, Angelica Crottini, Valeria Prada, Marco FerragutiAbstract:Tubifex blanchardi Vejdovský, 1891 is a freshwater tubificid, often living in sympatry with Tubifex Tubifex (Muller 1774). Although considered from its discovery as a species on its own, its biological status is debated. During the early seventies T. blanchardi was reduced to a mere form of T. Tubifex, as a particular case of polymorphism in chaetal pattern. Using classical histological techniques, microdissections of portions of the male genital apparatus and phalloidin staining of dissected copulatory organs we investigated 163 mixed individuals of T. blanchardi and T. Tubifex belonging to sympatric populations from the Lambro River (Milan, Northern Italy). The internal morphology of T. blanchardi is described for the first time. Our results show that T. Tubifex and T. blanchardi differ in several characters concerning both their external and internal morphology, and in the fine organization of their copulatory organs. Several independent character sets support the separation of T. blanchardi from T. Tubifex, suggesting that it is an independent species. This study also supports the idea that T. blanchardi and T. bergi (Hrabě, 1935), another species closely related to T. Tubifex, are not conspecific. The observed morphological differences between allopatric populations of T. Tubifex are discussed.
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the world in a river a preliminary analysis of the 16s rdna variability of Tubifex species clitellata tubificidae from the lambro river
Molecular Phylogenetics and Evolution, 2008Co-Authors: Angelica Crottini, Roberto Marotta, Michela Barbuto, Maurizio Casiraghi, Marco FerragutiAbstract:Tubifex Tubifex Muller, 1774 is a cosmopolitan freshwater tubificid widely used as a model in ecotoxicology, population dynamics and developmental biology. It is traditionally recognized as a polytypic species and in Lambro River (Milano, Northern Italy) it occurs in two of the three recognized forms, named "Tubifex" and "blanchardi", alternatively considered as ecological forms or distinct species. To investigate the genetic differentiation of the populations occurring in the Lambro River we sequenced a fragment of the 16S rDNA mitochondrial gene. T. blanchardi, characterized by a low genetic diversity, was genetically segregated from the other sympatric T. Tubifex. The ancestral state reconstruction was used to define the morphological traits that support its distinctness. On the contrary, the other T. Tubifex from the Lambro community, although morphologically indistinguishable, revealed an astonishing degree of genetic variability, both between and within the three identified clades that proved to be genetically isolated. Using samples from the mixed Lambro River community and from other countries around the world we present an overview of the species complex' 16S rDNA variability. Our results show that the genetic variability did not sensibly increase widening the data set, suggesting that the Lambro River populations meet the species' worldwide genetic variability.
Angelica Crottini - One of the best experts on this subject based on the ideXlab platform.
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alike but different the evolution of the Tubifex Tubifex species complex annelida clitellata through polyploidization
BMC Evolutionary Biology, 2014Co-Authors: Roberto Marotta, Angelica Crottini, Elena Raimondi, Cristina Fondello, Marco FerragutiAbstract:Background: Tubifex Tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. Tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. Results: The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. Tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. Conclusions: These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. Tubifex species complex.
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alike but different the evolution of the Tubifex Tubifex species complex annelida clitellata through polyploidization
BMC Evolutionary Biology, 2014Co-Authors: Roberto Marotta, Angelica Crottini, Elena Raimondi, Cristina Fondello, Marco FerragutiAbstract:Tubifex Tubifex is a widespread annelid characterized by considerable variability in its taxonomic characteristics and by a mixed reproductive strategy, with both parthenogenesis and biparental reproduction. In a molecular phylogenetic analysis, we detected substantial genetic variability among sympatric Tubifex spp. from the Lambro River (Milano, Italy), which we suggested comprise several cryptic species. To gain insights into the evolutionary events that generated this differentiation, we performed a cytogenetic analysis in parallel with a molecular assay. Approximately 80 cocoons of T. Tubifex and T. blanchardi were collected and dissected. For each cocoon, we sequenced a fragment of the 16S rRNA from half of the sibling embryos and karyotyped the other half. To generate a robust phylogeny enabling the reconstruction of the evolutionary processes shaping the diversity of these sympatric lineages, we complemented our original 16S rRNA gene sequences with additional COI sequences. The chromosome number distribution was consistent with the presence of at least six sympatric euploid chromosome complements (one diploid, one triploid, three tetraploids and one hexaploid), as confirmed by a FISH assay performed with an homologous 18S rDNA probe. All the worms with 2n = 50 chromosomes belonged to an already identified sibling species of T. Tubifex, T. blanchardi. The six euploid sets were coherently arranged in the phylogeny, with each lineage grouping specimens with the same chromosome complement. These results are compatible with the hypothesis that multiple polyploidization events, possibly enhanced by parthenogenesis, may have driven the evolution of the T. Tubifex species complex.
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a morphological reappraisal of Tubifex blanchardi vejdovský 1891 clitellata tubificidae
Acta Zoologica, 2009Co-Authors: Roberto Marotta, Angelica Crottini, Valeria Prada, Marco FerragutiAbstract:Tubifex blanchardi Vejdovský, 1891 is a freshwater tubificid, often living in sympatry with Tubifex Tubifex (Muller 1774). Although considered from its discovery as a species on its own, its biological status is debated. During the early seventies T. blanchardi was reduced to a mere form of T. Tubifex, as a particular case of polymorphism in chaetal pattern. Using classical histological techniques, microdissections of portions of the male genital apparatus and phalloidin staining of dissected copulatory organs we investigated 163 mixed individuals of T. blanchardi and T. Tubifex belonging to sympatric populations from the Lambro River (Milan, Northern Italy). The internal morphology of T. blanchardi is described for the first time. Our results show that T. Tubifex and T. blanchardi differ in several characters concerning both their external and internal morphology, and in the fine organization of their copulatory organs. Several independent character sets support the separation of T. blanchardi from T. Tubifex, suggesting that it is an independent species. This study also supports the idea that T. blanchardi and T. bergi (Hrabě, 1935), another species closely related to T. Tubifex, are not conspecific. The observed morphological differences between allopatric populations of T. Tubifex are discussed.
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the world in a river a preliminary analysis of the 16s rdna variability of Tubifex species clitellata tubificidae from the lambro river
Molecular Phylogenetics and Evolution, 2008Co-Authors: Angelica Crottini, Roberto Marotta, Michela Barbuto, Maurizio Casiraghi, Marco FerragutiAbstract:Tubifex Tubifex Muller, 1774 is a cosmopolitan freshwater tubificid widely used as a model in ecotoxicology, population dynamics and developmental biology. It is traditionally recognized as a polytypic species and in Lambro River (Milano, Northern Italy) it occurs in two of the three recognized forms, named "Tubifex" and "blanchardi", alternatively considered as ecological forms or distinct species. To investigate the genetic differentiation of the populations occurring in the Lambro River we sequenced a fragment of the 16S rDNA mitochondrial gene. T. blanchardi, characterized by a low genetic diversity, was genetically segregated from the other sympatric T. Tubifex. The ancestral state reconstruction was used to define the morphological traits that support its distinctness. On the contrary, the other T. Tubifex from the Lambro community, although morphologically indistinguishable, revealed an astonishing degree of genetic variability, both between and within the three identified clades that proved to be genetically isolated. Using samples from the mixed Lambro River community and from other countries around the world we present an overview of the species complex' 16S rDNA variability. Our results show that the genetic variability did not sensibly increase widening the data set, suggesting that the Lambro River populations meet the species' worldwide genetic variability.
Haroldo Lobo - One of the best experts on this subject based on the ideXlab platform.
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acute toxicity of zinc and arsenic to the warmwater aquatic oligochaete branchiura sowerbyi as compared to its coldwater counterpart Tubifex Tubifex annelida clitellata
Journal of Soils and Sediments, 2016Co-Authors: Haroldo Lobo, Leire Mendezfernandez, Maite Martinezmadrid, Michiel A Daam, Evaldo Luiz Gaeta EspindolaAbstract:Purpose This study aimed at evaluating the acute effects of arsenic and zinc to the warmwater aquatic oligochaete Branchiura sowerbyi. Relative sensitivity with the coldwater species Tubifex Tubifex was compared. Implications for the use of B. sowerbyi in the risk assessment of sediments in the tropics are discussed.
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acute toxicity of zinc and arsenic to the warmwater aquatic oligochaete branchiura sowerbyi as compared to its coldwater counterpart Tubifex Tubifex annelida clitellata
Journal of Soils and Sediments, 2016Co-Authors: Haroldo Lobo, Leire Mendezfernandez, Maite Martinezmadrid, Michiel A Daam, Evaldo Luiz Gaeta EspindolaAbstract:This study aimed at evaluating the acute effects of arsenic and zinc to the warmwater aquatic oligochaete Branchiura sowerbyi. Relative sensitivity with the coldwater species Tubifex Tubifex was compared. Implications for the use of B. sowerbyi in the risk assessment of sediments in the tropics are discussed. Water-only (96 h) and sediment (14 days) toxicity tests were conducted with both species evaluating a concentration series of arsenic and zinc. The tests were conducted considering the environmental conditions in the natural habitat of T. Tubifex (predominantly temperate) and B. sowerbyi (predominantly tropical). Both lethal and sublethal endpoints (autotomy of the posterior body parts, abnormal behavior and appearance) were determined in the tests. The lethal (LC10 and LC50) and effect (EC10 and EC50) concentrations were also determined to assess metal sensitivity for both species. Both test species were more sensitive to Zn than As in water-only tests, which is in agreement with previous studies evaluating the toxicity of these metals to aquatic oligochaetes. Sublethal effects were generally noted at concentrations lower than those leading to mortality. The warmwater oligochaete B. sowerbyi was more sensitive to both metals tested than the coldwater species T. Tubifex. Study findings support the need for using indigenous tropical species in risk assessments in the tropics. In addition, sublethal effect parameters should be included in toxicity testing with aquatic oligochaetes.
