7 research outputs found
Caracterização de sequências de DNA expressas durante o desenvolvimento de órgãos reprodutivos de Brachiaria brizantha (Hochst. ex A. Rich.) Stapf
Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, 2012.Brachiaria brizantha é uma gramínea forrageira da família Poaceae, introduzida da África, e amplamente utilizada no Brasil. Brachiaria se reproduz de modo sexual ou assexual por apomixia, clonagem de plantas por sementes. O desenvolvimento de ferramentas biotecnológicas para transferência de genes é de grande interesse para os programas de melhoramento desse gênero. As bases moleculares da reprodução ainda não estão bem elucidadas, a formação do gametófito e os principais eventos reprodutivos ocorrem dentro das anteras e ovários, sendo de grande interesse a identificação de genes expressos nesses órgãos e suas regiões regulatórias. Neste trabalho foram escolhidas sete sequências de cDNA de alta expressão em ovários de Brachiaria, na megasporogênese e megagametogênese com objetivo de isolar as sequências promotoras desses genes. As regiões codificadoras dos cDNA foram amplificadas de modo a ter essa região completa e conhecer a função inferida em bancos de dados. As sete sequências estudadas tiveram maior expressão em órgãos reprodutivos (ovários e anteras) e raízes quando comparada a folhas. Transcritos desses genes foram localizados em diferentes tecidos de ovários e anteras. A região codificadora completa e a região promotora putativa foram obtidas para BbrizRPS8, BbrizRPS15a e BbrizRPL41, nomeados neste trabalho em função da similaridade com os genes codificadores de proteínas ribossomais correspondentes. A expressão de BbrizRPS8, BbrizRPS15a e BbrizRPL41 foi observada em células mitoticamente ativas, em tecidos em crescimento do óvulos, anteras e raízes, consistente com a expressão de genes que codificam proteínas ribossomais em outras plantas, sugerindo envolvimento desses genes em atividades gerais de regulação do crescimento e desenvolvimento de órgãos reprodutivos e raízes, independentemente do modo de reprodução. As regiões promotoras putativas de BbrizRPS8, BbrizRPS15a e BbrizRPL41 foram capazes de dirigir a expressão transiente do gene repórter GUS em unidades embriogênicas de arroz e flores de Arabidopsis thaliana e poderão ser utilizadas em futuras análises de expressão de genes de interesse em órgãos reprodutivos. _______________________________________________________________________________________ ABSTRACTBrachiaria brizantha is a forage grass of the Poaceae family, introduced from Africa and largely used in Brazil. Brachiaria reproduces sexually or asexually by apomixis, an asexual mode of reproduction through seeds. The development of biotechnological tools for gene transfer is being researched to support the breeding programs on this genus. The molecular bases of reproduction have not yet been fully elucidated, however it is known that gametophyte formation and main reproductive events occur inside the anthers and ovaries. There is therefore much interest in identifying expressed genes and their corresponding upstream regulatory sequences in these organs. In this work seven cDNA sequences with higher expression in ovaries of Brachiaria at megasporogenesis and megagametogenesis were chosen in order to isolate the corresponding promoter sequences. The open read frame (ORF) of cDNAs were amplified and their function inferred in databases. The seven sequences studied had higher expression in reproductive organs (ovaries and anthers) and roots compared to leaves. Transcripts of these genes were located in different tissues of ovaries and anthers. The complete coding region and putative promoter region were obtained for clones BbrizRPS8, and BbrizRPS15a BbrizRPL41 as nominated in this work due to their similarities with corresponding genes encoding ribosomal proteins. The expression of BbrizRPS8, BbrizRPS15a and BbrizRPL41 was observed in mitotically active cells, in growing ovule, anthers and roots, consistent with the expression of genes encoding ribosomal proteins in other plants, suggesting that these genes could be involved in general activities regulating growth and development of reproductive organs and roots, irrespective of the mode of reproduction. The putative promoter regions of BbrizRPS8, BbrizRPS15a and BbrizRPL41 were able to drive transient expression of the reporter gene GUS in the embryogenic units of rice and Arabidopsis thaliana flowers and may be used for future analysis of expression of genes in reproductive organs
Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural
oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3 e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um.
Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue
Brachiaria brizantha : caracterização de cDNA de ovários e identificação de explantes para transformação via biobalística
Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, 2007.Brachiaria é uma gramínea de grande importância econômica. Amplamente utilizada no Brasil como forrageira sendo cultivada em uma área de aproximadamente 70 milhões de hectares. A grande demanda no uso de Brachiaria como pastagem é devida à fácil adaptação a solos ácidos e pobres, resistência a seca e a pragas, e à grande qualidade nutricional adequada para alimentação bovina. Uma das limitações ao melhoramento de Brachiaria é a presença da apomixia, modo de reprodução onde há clonagem através de sementes. A transformação genética de plantas amplia a possibilidade de introdução de características de interesse como também o estudo da expressão dos genes que controlam a apomixia. Neste trabalho foram utilizadas duas abordagens de interesse para o estudo da apomixia em Brachiaria. A primeira objetiva a caracterização de seqüências de cDNA de expressão específica em ovário e a segunda objetiva otimizar o sistema de transformação. Foi demonstrada a órgão-especificidade de seqüências de cDNA isoladas de ovários de plantas apomíticas e sexuais de B. brizantha, clones 09 e 21. Paralelamente, o uso de segmentos basais de plantas in vitro e aspectos do processo de indução de embriogênese somática e regeneração de diferentes explantes foram analisados visando melhor eficiência do sistema de transformação genética de Brachiaria. Na análise dos segmentos basais por microscopia, foi observado que apesar da grande proliferação de gemas nesses segmentos basais em meio de micropropagação, suas regiões meristemáticas não são expostas, não sendo acessíveis às partículas durante o bombardeamento. Dentro do sistema de embriogênese somática embriões isolados de sementes maduras, calos embriogênicos e células em suspensão foram analisados. De acordo com os resultados, as células em suspensão mostraram os melhores resultados quanto à homogeneidade de estruturas, à formação de embriões e alta taxa de regeneração, indicando que poderão ser usadas como explantes na transformação genética por biobalística em Brachiaria. _______________________________________________________________________________ ABSTRACTBrachiaria is a forage grass of great economic importance. Widely used as forage for cattle in Brazil, it is cultivated in about 70 million hectares. Its economic value is due to its adaptability to poor and acid soil, spittlebug and dry resistance and high nutritional quality. One limiting factor in Brachiaria breeding is apomixis, an assexual reproduction through seeds. Plant transformation increases the possibilities to introduce interesting characteristics and also could be a tool for gene expression studies that control apomixis. In this present work two relevant approaches for the apomixis studies of Brachiaria were used. The first one aims to identify sequences of cDNA with specific expressions in ovary and the second one aims to optimize the system of transformation. Therefore, was demonstrated the organ-specificity of ovary cDNA sequences isolated from apomitic and sexual B. brizantha, clones 09 and 21. Also, the use of basal segments of in vitro plants, aspects of somatic embriogenic induction, regeneration of different explants was analyzed aiming a better Brachiaria transformation efficiency. The evaluation of basal segments for transformation, microscopy analysis showed that, even with high bud proliferation of these segments, their meristematic regions were not exposed and for that not accessible to biolistic DNA coated particles. The explants analyzed in somatic embryogenesis were embryos isolated from mature seeds, embriogenic calli and culture cells. According to the experiments, culture cells showed better results concerning the homogeneity of the structures, embryo formation and regeneration rates and for that they will be used as explants in Brachiaria biolistic transformation
Exílio escravista: Hercule Florence e as fronteiras do açúcar e do café no Oeste paulista (1830-1879)
RESUMO O artigo investiga a trajetória do artista e inventor Antonie Hercule Romuald Florence (1804-1879) na sociedade escravista brasileira do século XIX, procurando examinar os fundamentos do "sentimento de exílio" que marcou sua longa vivência no Oeste de São Paulo. Na primeira parte, trato Florence como um observador das paisagens escravistas do açúcar e do café. A série de desenhos e aquarelas que compôs sobre a fazenda Ibicaba e o engenho da Cachoeira nos permite observar como ele apreendeu os processos concretos de transformação agrária e ambiental da fronteira escravista de São Paulo. Na segunda parte, analiso a conversão de Florence em cafeicultor escravista, momento em ele assumiu por razões familiares a gestão de uma propriedade cafeeira com trinta escravos no município de Campinas
NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics
Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data
NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics
Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data
NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics
Xenarthrans—anteaters, sloths, and armadillos—have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, 10 anteaters, and 6 sloths. Our data set includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the southern United States, Mexico, and Caribbean countries at the northern portion of the Neotropics, to the austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n = 5,941), and Cyclopes sp. have the fewest (n = 240). The armadillo species with the most data is Dasypus novemcinctus (n = 11,588), and the fewest data are recorded for Calyptophractus retusus (n = 33). With regard to sloth species, Bradypus variegatus has the most records (n = 962), and Bradypus pygmaeus has the fewest (n = 12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other data sets of Neotropical Series that will become available very soon (i.e., Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans data set. Please cite this data paper when using its data in publications. We also request that researchers and teachers inform us of how they are using these data