58 research outputs found

    Floral gene resources from basal angiosperms for comparative genomics research

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    BACKGROUND: The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST) sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants. RESULTS: Random sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04) generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i) proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii) many known floral gene homologues have been captured, and (iii) phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms. CONCLUSION: Initial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage-specific gene duplication and functional divergence, and analyses of adaptive molecular evolution. Since not all genes in the floral transcriptome will be associated with flowering, these EST resources will also be of interest to plant scientists working on other functions, such as photosynthesis, signal transduction, and metabolic pathways

    Identification of Chromosomes with Secondary Constrictions in \u3ci\u3eMelilotus\u3c/i\u3e Species

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    Secondary constrictions were determined in one chromosome pair in the complements of M. infesta, M. macrocarpa, M. italica (subgenus Micromeliotus), and M. alba and M. officinalis (subgenus Meliotus). The karyotypes of M. infesta and M. macrocarpa were found to be similar. Chromosomes of M. italica were larger than the chromosomes of the other four Melilotus species. The chromosome size in M. italica suggests the presence of large chromosomes in an ancestral or pro-Melilotus prototype. The chromosomes with satellites of M. infesta and M. macrocarpa appear to differ in morphology from the satellite chromosomes of M. alba and M. officinalis by a paracentric inversion. The morphology of the satellite chromosomes in M. italica is thought to represent a more primitive type than in the other Meliotus species studied

    Ambiente de trabajo cooperativo en internet para la educación en valores

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    TesisEl presente trabajo de investigación que lleva por título "AMBIENTE DE TRABAJO COOPERATIVO EN INTERNET PARA LA EDUCACION EN VALORES" responde a la necesidad de desarrollar nuevas formas de planificar y desarrollar la educación, de manera que se promueva la participación sincrónica y asincrónica entre tos sujetos que no se encuentran físicamente en el mismo lugar, ni en las mismas coordenadas temporales. El objetivo fue desarrollar un Ambiente de Trabajo Cooperativo en Internet para la educación en valores utilizando la Metodología Orientada a objetos y la Filosofía de Software Libre propiciando básicamente la reunión síncrona y. asíncrona para los miembros de la Federación de Familias para la Paz Mundial. Se ha utilizado Moodle, el cual es un . proyecto en desarrollo diseñado para dar soporte a un marco de educación social . constructivista. Esta herramienta se ha integrado al Ambiente de Trabajo Cooperativo principalmente para diseñar diferentes cursos en diferentes niveles y a diferentes usuarios. Tambíén se ha empleado los indicadores de calidad del Estándar IS0-9126, tales como funcionalidad, fiabilidad, usabilidad, eficiencia, mantenibilidad y portabilidad en una escala de 1 a 5 puntos. Se llega a la conclusión de que los ambientes de trabajo cooperativos para la educación en valores, permite mejorar el proceso de educación básicamente en la comunicación de los miembros de la Federación de Familias para la Paz Mundial cumpliendo con aprobar el estándar de calidad de software ISO 9126 en el que se observa que un 60% de los profesionales de cada país dicen que el Ambiente de Trabajo Cooperativo es bueno y un 10% afirma que es muy bueno. Palabras Claves: Ambiente de trabajo cooperativo, valores, internet, educació

    Geographically extensive hybridization between the forest trees American butternut and Japanese walnut

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    We investigate the question of naturally occurring interspecific hybrids between two forest trees: the native North American butternut (Juglans cinerea L.) and the introduced Japanese walnut (Juglans ailantifolia Carrière). Using nuclear and chloroplast DNA markers, we provide evidence for 29 F1 and 22 advanced generation hybrids in seven locations across the eastern and southern range of the native species. Two locations show extensive admixture (95% J. ailantifolia and hybrids) while other locations show limited admixture. Hybridization appears to be asymmetrical with 90.9 per cent of hybrids having J. ailantifolia as the maternal parent. This is, to our knowledge, the first genetic data supporting natural hybridization between these species. The long-term outcome of introgression could include loss of native diversity, but could also include transfer of useful traits from the introduced species

    Hoban_J_cinerea_Mol_Ecol_2010_Microsat_Data_Dryad

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    This file contains the microsatellite genotypes for 11 loci and 904 individuals, in 29 natural populations (forest) of butternut (J cinerea L) across eastern North America. These are the data referred to in the first sentence of the Results. They are data AFTER removal of hybrid individuals, identical genotypes, or individuals with too much missing data. These data are therefore the data used to calculate all statistics in the paper. The data are in GENEPOP format. The names of individuals are unique identification numbers used in our lab. The names of the loci correspond to those from Robichaud et al, and Hoban et al, as described in the Materials and Methods of the paper

    Hoban_EvolApps_microsat_Data_For_Dryad

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    The genotypes for trees used in this study for all analyses, after clones, etc. have been removed. The data are referred to in the publication as "1515 unique genotypes for analysis: 79 J. ailantifolia reference, 7 hybrid 231 reference, 66 J. cinerea reference, and 1363 naturally occurring trees." The names of the populations are as in table one, or similar abbreviation. File format is Convert, tab delimited. All 12 microsatellite loci. Missing data with a '?'. Details about collections are in the manuscript
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