The Experts below are selected from a list of 2016 Experts worldwide ranked by ideXlab platform
Vincenzo Penteriani - One of the best experts on this subject based on the ideXlab platform.
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buho real Bubo Bubo linnaeus 1758
2016Co-Authors: Vincenzo Penteriani, Maria Del Mar Delgado, Alfredo Salvador MillaAbstract:Aves - Orden Strigiformes - Familia Strigidae en la Enciclopedia Virtual de Vertebrados Espanoles, http://www.vertebradosibericos.org/. Versiones anteriores: 30-03-2010
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limited prospecting behaviour of juvenile eagle owls Bubo Bubo during natal dispersal implications for conservation
Bird Study, 2016Co-Authors: Antonio Fasciolo, Maria Del Mar Delgado, Gonzalo D Cortes, Alvaro Soutullo, Vincenzo PenterianiAbstract:Capsule Features of the breeding population and temporary settlement area influence the behaviour of Eagle Owls Bubo Bubo prospecting for breeding sites during natal dispersal.Aims To understand how prospecting behaviour during natal dispersal is affected by (i) the main characteristics of the breeding and dispersing portions of the population and (ii) main prey availability.Methods We explored the ten-year dynamics and characteristics of radio-tagged breeders and dispersers of an Eagle Owl population.Results During the first years following natal dispersal there was little prospecting behaviour of nesting sites and birds remained mainly within non-breeding settlement areas, bordering the sector occupied by the breeding population. Settlement areas had an abundant food supply, and low intraspecific competition and mortality. We suggest that these features of the settlement areas may reduce the willingness of individuals to search for breeding sites and may have the potential to impact on the viability of ...
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vocal behaviour and neighbour spatial arrangement during vocal displays in eagle owls Bubo Bubo
Journal of Zoology, 2007Co-Authors: Maria Del Mar Delgado, Vincenzo PenterianiAbstract:We quantified temporal and spatial patterns of adult eagle owl Bubo Bubo vocal behaviour throughout an entire year. The duration of adult eagle owl vocal displays showed significant differences during different periods of the year: there was one major peak in the pre-laying period, when duets of mates were also more frequent. The daily distribution of adult vocalizations showed a similar pattern among the different periods, with vocal activity being most intense at sunset and sunrise. Analyses of the characteristics of call posts showed that the choice of such focal points was guided by the trade-off between the need to defend the territory and within-pair communication inside the core areas, as well as efficient communication with neighbours.
Joaquin Ortego - One of the best experts on this subject based on the ideXlab platform.
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factors associated with the geographic distribution of leucocytozoa parasitizing nestling eagle owls Bubo Bubo a local spatial scale analysis
Conservation Genetics, 2010Co-Authors: Joaquin Ortego, Pedro J CorderoAbstract:Knowledge of the factors influencing the patterns and distribution of parasite infections and disease outbreaks is a major question in disease ecology and conservation research. In this study, we use a highly efficient PCR approach to detect blood parasites and investigate the factors influencing geographical variation in the distribution of leucocytozoids parasitizing nestling eagle owls (Bubo Bubo) over a 3-year study period. We found that both prevalence and intensity of infections by the single lineage of Leucocytozoon ziemanni infecting nestling eagle owls in the study area increased with local owl population density and decreased with nest height above sea level. Overall, these results suggest that higher horizontal transmission rates under higher host density conditions together with the presence of adequate habitats for larval development of vectors are relevant factors influencing blood parasite distribution in the study system.
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pcr based detection and genotyping of haematozoa protozoa parasitizing eagle owls Bubo Bubo
Parasitology Research, 2009Co-Authors: Joaquin Ortego, Pedro J CorderoAbstract:We genetically analysed haematozoa parasites (Protozoa) isolated from nestling eagle owls (Bubo Bubo) in Toledo province, Central Spain. A total of 206 nestlings from 74 nests were screened for parasites of the genera Leucocytozoon, Plasmodium, and Haemoproteus using a very efficient polymerase chain reaction (PCR) approach that amplifies a partial segment of the mitochondrial cytochrome b gene of these parasites. PCR-based detection and sequence analyses revealed a unique lineage of Leucocytozoon (EO1) parasitizing nestling eagle owls. Ocular examination of blood smears identified these parasites as Leucocytozoon ziemanni, the only species deemed valid in owls based on morphology. Preliminary phylogenetic analyses using homologous published sequences isolated from other owl species suggest that L. ziemanni constitutes a monophyletic clade that may be composed by a complex of genetically differentiated cryptic species.
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habitat preference models for nesting eagle owls Bubo Bubo how much can be inferred from changes with spatial scale
2004Co-Authors: Joaquin Ortego, Mario DiazAbstract:SUMMARY.—Habitat preference models for nesting Eagle Owls Bubo Bubo: How much can be inferred from changes with spatial scale? Aims: To analyze whether habitat preference patterns of the Eagle Owl Bubo Bubo change with spatial scale in an area of very high rabbit Oryctolagus cuniculus density as compared to an area of lower prey availability (Martinez et al., 2003a). Location: An area of over 2,100 km 2 located in the province of Toledo, central Spain. Methods: 17 habitat variables were measured around 100 nests that were occupied between 1999 and 2003 and around 100 random points at four spatial scales (circular areas of 250, 500, 1000 and 1,500 m of radius). The range of spatial scales was established on the basis of the observed high density of Eagle Owl nests in the study area, the second highest reported to date. Habitat features of occupied and random areas were compared by means of logistic regressions for each spatial scale. The possible effect of the spatial autocorrelation was assessed using as additional predictors all the terms of a cubic equation defined by the coordinates of the sampling points. Results: Topographic irregularity and distance to the nearest stream were included into the models at all scales as the main predictors of the presence of Eagle Owl nests, classifying a high percentage of both random and occupied points. Percent correct classification of the models did not change across scales. Positive selection of areas with irregular topography and close to streams can be interpreted as due either to a choice of protected areas for nest location and/or of areas with high prey availability. At the 500 meters of radius scale the model included marginally the positive selection of areas with high covers of dehesa, a variable that may be interpreted in the same way that the selection for the two main predictors. Two terms (X and Y
Hassan Bousbaa - One of the best experts on this subject based on the ideXlab platform.
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kinetochore microtubule interactions in check by bub1 bub3 and bubr1 the dual task of attaching and signalling
Cell Cycle, 2008Co-Authors: Elsa Logarinho, Hassan BousbaaAbstract:The spindle assembly checkpoint (SAC) prevents anaphase onset until all chromosomes accomplish proper bipolar attachments to the mitotic spindle and come under tension, thereby ensuring the fidelity of chromosome segregation. Despite significant advances in our understanding of SAC signalling, a clear link between checkpoint signalling and the molecular mechanisms underlying chromosome attachment to microtubules has not been established so far. However, independent studies from many groups have interestingly found that the bone-a-fide Bub1, BubR1 and Bub3 SAC proteins are themselves required for proper kinetochore-microtubule (K-MT) interactions. Here, we review these findings and discuss the specific contribution of each of these proteins in the regulation of K-MT attachment, taking into consideration their interdependencies for kinetochore localization as well as their relationship with other proteins with a known role in chromosome attachment and congression.
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the human spindle assembly checkpoint protein bub3 is required for the establishment of efficient kinetochore microtubule attachments
Molecular Biology of the Cell, 2008Co-Authors: Elsa Logarinho, Tatiana P Resende, Claudia Torres, Hassan BousbaaAbstract:The spindle assembly checkpoint monitors the status of kinetochore-microtubule (K-MT) attachments and delays anaphase onset until full metaphase alignment is achieved. Recently, the role of spindle assembly checkpoint proteins was expanded with the discovery that BubR1 and Bub1 are implicated in the regulation of K-MT attachments. One unsolved question is whether Bub3, known to form cell cycle constitutive complexes with both BubR1 and Bub1, is also required for proper chromosome-to-spindle attachments. Using RNA interference and high-resolution microscopy, we analyzed K-MT interactions in Bub3-depleted cells and compared them to those in Bub1- or BubR1-depleted cells. We found that Bub3 is essential for the establishment of correct K-MT attachments. In contrast to BubR1 depletion, which severely compromises chromosome attachment and alignment, we found Bub3 and Bub1 depletions to produce defective K-MT attachments that, however, still account for significant chromosome congression. After Aurora B inhibition, alignment defects become severer in Bub3- and Bub1-depleted cells, while partially rescued in BubR1-depleted cells, suggesting that Bub3 and Bub1 depletions perturb K-MT attachments distinctly from BubR1. Interestingly, misaligned chromosomes in Bub3- and Bub1-depleted cells were found to be predominantly bound in a side-on configuration. We propose that Bub3 promotes the formation of stable end-on bipolar attachments.
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different spindle checkpoint proteins monitor microtubule attachment and tension at kinetochores in drosophila cells
Journal of Cell Science, 2004Co-Authors: Elsa Logarinho, Claudio E Sunkel, Hassan Bousbaa, Jose M Dias, Carla S Lopes, Isabel Amorim, Ana AntunesmartinsAbstract:The spindle assembly checkpoint detects errors in kinetochore attachment to the spindle including insufficient microtubule occupancy and absence of tension across bi-oriented kinetochore pairs. Here, we analyse how the kinetochore localization of the Drosophila spindle checkpoint proteins Bub1, Mad2, Bub3 and BubR1, behave in response to alterations in microtubule binding or tension. To analyse the behaviour in the absence of tension, we treated S2 cells with low doses of taxol to disrupt microtubule dynamics and tension, but not kinetochore-microtubule occupancy. Under these conditions, we found that Mad2 and Bub1 do not accumulate at metaphase kinetochores whereas BubR1 does. Consistently, in mono-oriented chromosomes, both kinetochores accumulate BubR1 whereas Bub1 and Mad2 only localize at the unattached kinetochore. To study the effect of tension we analysed the kinetochore localization of spindle checkpoint proteins in relation to tension-sensitive kinetochore phosphorylation recognised by the 3F3/2 antibody. Using detergent-extracted S2 cells as a system in which kinetochore phosphorylation can be easily manipulated, we observed that BubR1 and Bub3 accumulation at kinetochores is dependent on the presence of phosphorylated 3F3/2 epitopes. However, Bub1 and Mad2 localize at kinetochores regardless of the 3F3/2 phosphorylation state. Altogether, our results suggest that spindle checkpoint proteins sense distinct aspects of kinetochore interaction with the spindle, with Mad2 and Bub1 monitoring microtubule occupancy while BubR1 and Bub3 monitor tension across attached kinetochores.
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localization of the drosophila checkpoint control protein bub3 to the kinetochore requires bub1 but not zw10 or rod
Chromosoma, 1998Co-Authors: Joydeep Basu, Claudio E Sunkel, Elsa Logarinho, Hassan Bousbaa, Siegrun Herrmann, Gordon K Chan, Tim J Yen, Michael L GoldbergAbstract:We report here the isolation and molecular characterization of the Drosophila homolog of the mitotic checkpoint control protein Bub3. The Drosophila Bub3 protein is associated with the centromere/kinetochore of chromosomes in larval neuroblasts whose spindle assembly checkpoints have been activated by incubation with the microtubule-depolymerizing agent colchicine. Drosophila Bub3 is also found at the kinetochore regions in mitotic larval neuroblasts and in meiotic primary and secondary spermatocytes, with the strong signal seen during prophase and prometaphase becoming increasingly weaker after the chromosomes have aligned at the metaphase plate. We further show that the localization of Bub3 to the kinetochore is disrupted by mutations in the gene encoding the Drosophila homolog of the spindle assembly checkpoint protein Bub1. Combined with recent findings showing that the kinetochore localization of Bub1 conversely depends upon Bub3, these results support the hypothesis that the spindle assembly checkpoint proteins exist as a multiprotein complex recruited as a unit to the kinetochore. In contrast, we demonstrate that the kinetochore constituents Zw10 and Rod are not needed for the binding of Bub3 to the kinetochore. This suggests that the kinetochore is assembled in at least two relatively independent pathways.
Pedro J Cordero - One of the best experts on this subject based on the ideXlab platform.
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factors associated with the geographic distribution of leucocytozoa parasitizing nestling eagle owls Bubo Bubo a local spatial scale analysis
Conservation Genetics, 2010Co-Authors: Joaquin Ortego, Pedro J CorderoAbstract:Knowledge of the factors influencing the patterns and distribution of parasite infections and disease outbreaks is a major question in disease ecology and conservation research. In this study, we use a highly efficient PCR approach to detect blood parasites and investigate the factors influencing geographical variation in the distribution of leucocytozoids parasitizing nestling eagle owls (Bubo Bubo) over a 3-year study period. We found that both prevalence and intensity of infections by the single lineage of Leucocytozoon ziemanni infecting nestling eagle owls in the study area increased with local owl population density and decreased with nest height above sea level. Overall, these results suggest that higher horizontal transmission rates under higher host density conditions together with the presence of adequate habitats for larval development of vectors are relevant factors influencing blood parasite distribution in the study system.
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pcr based detection and genotyping of haematozoa protozoa parasitizing eagle owls Bubo Bubo
Parasitology Research, 2009Co-Authors: Joaquin Ortego, Pedro J CorderoAbstract:We genetically analysed haematozoa parasites (Protozoa) isolated from nestling eagle owls (Bubo Bubo) in Toledo province, Central Spain. A total of 206 nestlings from 74 nests were screened for parasites of the genera Leucocytozoon, Plasmodium, and Haemoproteus using a very efficient polymerase chain reaction (PCR) approach that amplifies a partial segment of the mitochondrial cytochrome b gene of these parasites. PCR-based detection and sequence analyses revealed a unique lineage of Leucocytozoon (EO1) parasitizing nestling eagle owls. Ocular examination of blood smears identified these parasites as Leucocytozoon ziemanni, the only species deemed valid in owls based on morphology. Preliminary phylogenetic analyses using homologous published sequences isolated from other owl species suggest that L. ziemanni constitutes a monophyletic clade that may be composed by a complex of genetically differentiated cryptic species.
Elsa Logarinho - One of the best experts on this subject based on the ideXlab platform.
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kinetochore microtubule interactions in check by bub1 bub3 and bubr1 the dual task of attaching and signalling
Cell Cycle, 2008Co-Authors: Elsa Logarinho, Hassan BousbaaAbstract:The spindle assembly checkpoint (SAC) prevents anaphase onset until all chromosomes accomplish proper bipolar attachments to the mitotic spindle and come under tension, thereby ensuring the fidelity of chromosome segregation. Despite significant advances in our understanding of SAC signalling, a clear link between checkpoint signalling and the molecular mechanisms underlying chromosome attachment to microtubules has not been established so far. However, independent studies from many groups have interestingly found that the bone-a-fide Bub1, BubR1 and Bub3 SAC proteins are themselves required for proper kinetochore-microtubule (K-MT) interactions. Here, we review these findings and discuss the specific contribution of each of these proteins in the regulation of K-MT attachment, taking into consideration their interdependencies for kinetochore localization as well as their relationship with other proteins with a known role in chromosome attachment and congression.
-
the human spindle assembly checkpoint protein bub3 is required for the establishment of efficient kinetochore microtubule attachments
Molecular Biology of the Cell, 2008Co-Authors: Elsa Logarinho, Tatiana P Resende, Claudia Torres, Hassan BousbaaAbstract:The spindle assembly checkpoint monitors the status of kinetochore-microtubule (K-MT) attachments and delays anaphase onset until full metaphase alignment is achieved. Recently, the role of spindle assembly checkpoint proteins was expanded with the discovery that BubR1 and Bub1 are implicated in the regulation of K-MT attachments. One unsolved question is whether Bub3, known to form cell cycle constitutive complexes with both BubR1 and Bub1, is also required for proper chromosome-to-spindle attachments. Using RNA interference and high-resolution microscopy, we analyzed K-MT interactions in Bub3-depleted cells and compared them to those in Bub1- or BubR1-depleted cells. We found that Bub3 is essential for the establishment of correct K-MT attachments. In contrast to BubR1 depletion, which severely compromises chromosome attachment and alignment, we found Bub3 and Bub1 depletions to produce defective K-MT attachments that, however, still account for significant chromosome congression. After Aurora B inhibition, alignment defects become severer in Bub3- and Bub1-depleted cells, while partially rescued in BubR1-depleted cells, suggesting that Bub3 and Bub1 depletions perturb K-MT attachments distinctly from BubR1. Interestingly, misaligned chromosomes in Bub3- and Bub1-depleted cells were found to be predominantly bound in a side-on configuration. We propose that Bub3 promotes the formation of stable end-on bipolar attachments.
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different spindle checkpoint proteins monitor microtubule attachment and tension at kinetochores in drosophila cells
Journal of Cell Science, 2004Co-Authors: Elsa Logarinho, Claudio E Sunkel, Hassan Bousbaa, Jose M Dias, Carla S Lopes, Isabel Amorim, Ana AntunesmartinsAbstract:The spindle assembly checkpoint detects errors in kinetochore attachment to the spindle including insufficient microtubule occupancy and absence of tension across bi-oriented kinetochore pairs. Here, we analyse how the kinetochore localization of the Drosophila spindle checkpoint proteins Bub1, Mad2, Bub3 and BubR1, behave in response to alterations in microtubule binding or tension. To analyse the behaviour in the absence of tension, we treated S2 cells with low doses of taxol to disrupt microtubule dynamics and tension, but not kinetochore-microtubule occupancy. Under these conditions, we found that Mad2 and Bub1 do not accumulate at metaphase kinetochores whereas BubR1 does. Consistently, in mono-oriented chromosomes, both kinetochores accumulate BubR1 whereas Bub1 and Mad2 only localize at the unattached kinetochore. To study the effect of tension we analysed the kinetochore localization of spindle checkpoint proteins in relation to tension-sensitive kinetochore phosphorylation recognised by the 3F3/2 antibody. Using detergent-extracted S2 cells as a system in which kinetochore phosphorylation can be easily manipulated, we observed that BubR1 and Bub3 accumulation at kinetochores is dependent on the presence of phosphorylated 3F3/2 epitopes. However, Bub1 and Mad2 localize at kinetochores regardless of the 3F3/2 phosphorylation state. Altogether, our results suggest that spindle checkpoint proteins sense distinct aspects of kinetochore interaction with the spindle, with Mad2 and Bub1 monitoring microtubule occupancy while BubR1 and Bub3 monitor tension across attached kinetochores.
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localization of the drosophila checkpoint control protein bub3 to the kinetochore requires bub1 but not zw10 or rod
Chromosoma, 1998Co-Authors: Joydeep Basu, Claudio E Sunkel, Elsa Logarinho, Hassan Bousbaa, Siegrun Herrmann, Gordon K Chan, Tim J Yen, Michael L GoldbergAbstract:We report here the isolation and molecular characterization of the Drosophila homolog of the mitotic checkpoint control protein Bub3. The Drosophila Bub3 protein is associated with the centromere/kinetochore of chromosomes in larval neuroblasts whose spindle assembly checkpoints have been activated by incubation with the microtubule-depolymerizing agent colchicine. Drosophila Bub3 is also found at the kinetochore regions in mitotic larval neuroblasts and in meiotic primary and secondary spermatocytes, with the strong signal seen during prophase and prometaphase becoming increasingly weaker after the chromosomes have aligned at the metaphase plate. We further show that the localization of Bub3 to the kinetochore is disrupted by mutations in the gene encoding the Drosophila homolog of the spindle assembly checkpoint protein Bub1. Combined with recent findings showing that the kinetochore localization of Bub1 conversely depends upon Bub3, these results support the hypothesis that the spindle assembly checkpoint proteins exist as a multiprotein complex recruited as a unit to the kinetochore. In contrast, we demonstrate that the kinetochore constituents Zw10 and Rod are not needed for the binding of Bub3 to the kinetochore. This suggests that the kinetochore is assembled in at least two relatively independent pathways.
