399 research outputs found
3D-printable tools for developmental biology: Improving embryo injection and screening techniques through 3D-printing technology
Developmental biology requires rapid embryo injections and screening. We applied new affordable high-resolution 3D-printing to create five easily modifiable stamp-mold tools that greatly increase injection and screening speed, while simultaneously reducing the harmful aspects of these processes. We designed two stamps that use different approaches to improve the injection efficiency for two different types of embryo, first for embryos from the snail Crepidula fornicata, and second, for those from the spider Parasteatoda tepidariorum. Both drastically improved injection speeds and embryo survival rates, even in novice hands. The other three tools were designed for rapid side-by-side organism orientating and comparison. The first screening tool allows for optimal imaging in Xenopus laevis tadpoles, while the second and third facilitate rapid high-throughput screening of Xenopus tropicalis tadpoles and Danio rerio juveniles, respectively. These designs can act as templates for many injection or screening applications
Identification of Botanical Biomarkers in Argentinean Diplotaxis Honeys: Flavonoids and Glucosinolates
To select and establish floral biomarkers of the botanical origin ofDiplotaxis tenuifoliahoneys, the flavonoids and glucosinolates present in bee-deposited nectar collected from hive combs (unripe honey) and mature honey from the same hives fron which the unripe honey samples were collected were analyzed by LC-UV-PAD-ESI-MSn. Glycosidic conjugates of the flavonols quercetin, kaempferol, and isorhamnetin were detected and characterized in unripe honey.D. tenuifoliamature honeys contained the aglycones kaempferol, quercetin, and isorhamnetin. The differences between the phenolic profiles of mature honey and freshly deposited honey could be due to hydrolytic enzymatic activities. Aliphatic and indole glucososinolates were analyzed in unripe and mature honeys, this being the first report of the detection and characterization of glucosinolates as honey constituents. Moreover, these honey samples contained different amounts of propolis-derived flavonoid aglycones (1765−3171 μg/100 g) and hydroxycinnamic acid derivatives (29−1514 μg/100 g). Propolis flavonoids were already present in the freshly deposited nectar, showing that the incorporation of these compounds to honey occurs at the early steps of honey production. The flavonoids quercetin, kaempferol, and isorhamnetin and the glucosinolates detected in the samples could be used as complementary biomarkers for the determination of the floral origin of ArgentineanDiplotaxishoneys
Deployment of regulatory genes during gastrulation and germ layer specification in a model spiralian mollusc Crepidula
© 2015 Wiley Periodicals, Inc. Background: During gastrulation, endoderm and mesoderm are specified from a bipotential precursor (endomesoderm) that is argued to be homologous across bilaterians. Spiralians also generate mesoderm from ectodermal precursors (ectomesoderm), which arises near the blastopore. While a conserved gene regulatory network controls specification of endomesoderm in deuterostomes and ecdysozoans, little is known about genes controlling specification or behavior of either source of spiralian mesoderm or the digestive tract. Results: Using the mollusc Crepidula, we examined conserved regulatory factors and compared their expression to fate maps to score expression in the germ layers, blastopore lip, and digestive tract. Many genes were expressed in both ecto- and endomesoderm, but only five were expressed in ectomesoderm exclusively. The latter may contribute to epithelial-to-mesenchymal transition seen in ectomesoderm. Conclusions: We present the first comparison of genes expressed during spiralian gastrulation in the context of high-resolution fate maps. We found variation of genes expressed in the blastopore lip, mouth, and cells that will form the anus. Shared expression of many genes in both mesodermal sources suggests that components of the conserved endomesoderm program were either co-opted for ectomesoderm formation or that ecto- and endomesoderm are derived from a common mesodermal precursor that became subdivided into distinct domains during evolution.Spanish MICINN and the UAM, and funded by project CGL2011-29916 (MICINN)Peer Reviewe
Diversidad de patógenos en aves silvestres neotropicales: estrategias de descubrimiento e identificación del papel de las especies hospedadoras
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, leída el 02/02/2021With this PhD thesis, we want to shed some light on the field of pathogens circulating in wildlife, more specifically, in wild birds. In a global context where pathogen transmission among wildlife, domestic animals and humans is higher than ever before, studies following a discovery-driven approach are essential for human health and biodiversity conservation. However, with some exceptions, few pathogens have been studied in wild birds. In our research, we have focused on two important groups of pathogens carried by this group of animals: viruses and haemosporidians, two models that allow different perspectives in the study of avian pathogens, from discovery to ecological function. Furthermore, we want to highlight the value of remote regions as sources of novel information about pathogen diversity and discovery-driven approaches as essential tools for their study. To this end, we sampled the understory community of wild birds in a tropical rainforest of the Nouragues Natural Reserve (French Guiana) and we analyzed its cloacal virome and the community of haemosporidians infecting them.
The general objective of this PhD thesis is to highlight how discovery-driven research on pathogens of wildlife living in remote regions contributes substantially to expand the knowledge in the fields of virology and parasitology. With this information, we will improve the understanding of the diversity, host range, ecology and prevalence of both cloacal viruses and haemosporidians infecting birds from Nouragues. Therefore, the four main objectives of this thesis can be summarized in biodiscovery, screening of pathogens in Guianan birds, highlight remote regions and non-traditional hosts as sources of relevant new information in viral discovery and the analysis of avian malaria parasites in Nouragues...Con esta tesis doctoral se pretende arrojar luz en el campo de los patógenos que circulan en la fauna silvestre, más en concreto, en las aves silvestres. En un contexto global en el que la transmisión de patógenos entre fauna silvestre, animales domésticos y humanos es mayor que nunca, los estudios con aproximaciones enfocadas al descubrimiento de nuevos patógenos en la fauna silvestre son esenciales para la salud humana y la conservación de la biodiversidad. Sin embargo, con algunas excepciones, pocos son los patógenos estudiados en aves silvestres. En nuestra investigación, nos hemos centrado en dos grupos importantes de patógenos que portan este grupo de animales: los virus y los hemosporidios, dos modelos que permiten diferentes perspectivas en el estudio de los patógenos de aves. Además, pretendemos resaltar el valor de las zonas remotas como fuente de nueva información en el ámbito de la diversidad de patógenos y de las aproximaciones enfocadas al descubrimiento como una herramienta esencial para su estudio. Para ello, muestreamos la comunidad de aves silvestres del sotobosque en un bosque tropical húmedo de la Reserva Natural de Nouragues (Guayana Francesa) y analizamos su viroma cloacal y la comunidad de hemosporidios que los infectan.
El objetivo general de esta tesis es destacar cómo la investigación dirigida al descubrimiento de nuevos patógenos en fauna silvestre y zonas remotas contribuye sustancialmente a ampliar el conocimiento en los campos de la virología y la parasitología. Con esta información, se mejorará la comprensión de la diversidad, rango de hospedadores, ecología y prevalencia tanto de los virus cloacales como de los hemosporidios que infectan a las aves de Nouragues. Por tanto, los cuatro objetivos principales de esta tesis se resumen en biodescubrimiento, el cribado de patógenos en las aves de Guayana, resaltar los hospedadores no tradicionales y las zonas remotas como fuente de nueva información relevante en el descubrimiento de virus y el análisis de los parásitos de la malaria aviar en Nouragues...Fac. de Ciencias BiológicasTRUEunpu
El libro y sus partes: redacción, estilo y normas ortotipográficas
El principal objetivo de esta investigación se concreta en aspectos relacionados tanto con el plano editorial, en el que se centra prácticamente la mitad de este trabajo, como en el plano lingüístico. El estudio expresa de una manera clara y expositiva conceptos, normas, errores, pautas a seguir, acepciones correctas y excepciones íntimamente relacionadas con la expresión escrita y sus conexiones con la oralidad. A través de los distintos parámetros se va a conseguir una visualización general y particularizada de los diferentes aspectos relacionados con la ortografía, la tipografía, los errores ortotipográficos, los distintos modelos de contratos que relacionan el proceso editorial y las partes externas e internas del libro como elemento y soporte de la materia escrita que le caracteriza, sea con la impresión y encuadernación de ese conjunto de hojas, como por la visión a través de una pantalla digital más o menos grande. También se dan a conocer los distintos tipos de obra que se pueden realizar en una editorial explicando su casuística concreta. Se marca la diferencia entre ortografía y ortotipografía. Dos conceptos que parecen significar lo mismo pero que no es así. La Academia define ortografía como «conjunto de normas que regulan la escritura de una lengua» mientras que ortotipografía sería «conjunto de usos y convenciones particulares por las que se rige en cada lengua la escritura mediante signos tipográficos». Para terminar incidir en una de las premisas principales que se han de tener en cuenta al editar un libro: tener en cuenta, al lector, factor primordial a la hora de escribir. Todo lo especificado en este trabajo de investigación no serviría si el autor no le tiene en cuenta. Independientemente de los elevados conocimientos que posea sobre una materia concreta, el creativo tiene que ser capaz de hacerse entender, de ser comprendido y entendido
Expression pattern of nitric oxide synthase during development of the marine gastropod mollusc, Crepidula fornicata
Nitric Oxide (NO) plays a key role in the induction of larval metamorphosis in several
invertebrate phyla. The inhibition of the NO synthase in Crepidula fornicata, a molluscan model for
evolutionary, developmental, and ecological research, has been demonstrated to block the initiation
of metamorphosis highlighting that endogenous NO is crucial in the control of this developmental
and morphological process. Nitric Oxide Synthase contributes to the development of shell gland,
digestive gland and kidney, being expressed in cells that presumably correspond to FMRF-amide,
serotoninergic and catecolaminergic neurons. Here we identified a single Nos gene in embryonic
and larval transcriptomes of C. fornicata and studied its localization during development, through
whole-mount in situ hybridization, in order to compare its expression pattern with that of other
marine invertebrate animal modelsF.C. was supported by a SZN OU PhD fellowship. M.T.-G. was supported by a predoctoral
fellowship (Ref. BES-2012-052214 MICINN) and by the short-term stays program EEBB-1-16-11411.
C.G. was funded by project no CGL2011-29916. S.D. was funded by the NOEVO SZN projec
Evolution and development of bilateral asymmetries in Gastropoda the gene inversin and the Nodal pathway
Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 27-07-2017Esta tesis tiene embargado el acceso al texto completo hasta el 27-01-201
Selected phytochemical bioactive compounds as quorum sensing inhibitors
Bacterial infections remain an important problem for human health. The control of bacterial infections has been traditionally treated by inhibiting microbial growth using different types of antibiotics. However, the ability of different bacteria to resist the inhibitory action of antibiotics has become a global problem. In fact, there is an important need for the development of new antimicrobials that act on novel bacterial targets. Many pathogenic bacteria control their population and regulate gene expression in response to their cell population density using diffusible signalling com¬pounds. This type of communication has been referred to as “quorum sensing” (QS). This phenomenon can be essential for the synchronization of the virulence production factors, which make it an attractive therapeutic target. Therefore, the search of non-toxic compounds, which inhibit QS and so, the virulence of pathogenic bacteria can bring new alternatives for the treatment of bacterial infections in humans. In this work, we made an attempt to screen the anti-QS activity of 11 bioactive compounds extracted from fruits and vegetables using the biosensor strain, Chromobacterium violaceum. The anti-QS activity was determined quantifying the violacein production of the biosensor strain at three concentrations (50, 100 and 200 µg/ml). At least five of the tested compounds (cinnamaldehyde, pomegranate extracts, ellagic acid resveratrol and rutin) showed anti-QS activity against the biosensor strain. The obtained results showed the potential of bioactive compounds extracted from fruits and vegetables to be used as a new category of anti-pathogenic compounds against bacterial infections.Fil: Truchado , P.. Consejo Superior de Investigaciones Cientificas. Center For Research In Agricultural Genomics.; EspañaFil: Tomás Barberán, F.. Consejo Superior de Investigaciones Cientificas. Center For Research In Agricultural Genomics.; EspañaFil: Allende, A.. Consejo Superior de Investigaciones Cientificas. Center For Research In Agricultural Genomics.; EspañaFil: Ponce, Alejandra Graciela. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Departamento de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin
La implicación de las frutas y hortalizas en las toxiinfecciones alimentarias y la relevancia del estado fisiológico de las bacterias
Fruits and vegetables have always been in the news, mainly because of their beneficial properties for human health. However, they increasingly occupy headlines due to their involvement in foodborne outbreaks. This is the reason why, since 2008, many international organizations consider fruit and vegetables risky food. One major microbiological concern regarding the safety of leafy greens is that pathogenic microorganisms are able to adhere to and survive on plant tissue during cultivation and processing, coexist with epiphytic bacteria and persist for long periods of time. The prevalence of pathogenic microorganisms in fruits and vegetables is low (Las frutas y hortalizas han sido siempre noticia debido principalmente a sus propiedades beneficiosas para la salud. Sin embargo, cada vez más ocupan titulares debido a su implicación en toxiinfecciones alimentarias. Por este motivo, desde 2008, las frutas y hortalizas frescas son consideradas por muchos organismos internacionales como un alimento de riesgo. Uno de los principales problemas microbiológicos de las hortalizas de hojas son las bacterias entéricas que pueden adherirse rápidamente al tejido durante el cultivo, coexistir con las bacterias epífitas y persistir por largos periodos de tiempo. La prevalencia de microorganismos patógenos en las frutas y hortalizas es baja ( < 1%) y la cuantificación de las bacterias patógenas o de microorganismos indicadores generalmente muestra niveles muy bajos, lo que no justificaría el elevado número de alertas microbiológicas asociadas a este tipo de productos. Sin embargo, existen dudas sobre si los recuentos obtenidos utilizando las técnicas convencionales son capaces de reflejar realmente todos los microorganismos presentes en el producto vegetal, así como en el agua de riego y en el suelo. Varios estudios han demostrado que cuando las bacterias son sometidas a distintos factores de estrés entran en un estado temporal de baja actividad metabólica en el cual las células pueden persistir durante largos periodos de tiempo sin división celular, llamado estado de latencia o viable pero no cultivable (VBNC). La relevancia que el estado fisiológico de las bacterias puede tener en el desarrollo de toxiinfecciones alimentarias causadas por las frutas y hortalizas es un tema de gran interés que está atrayendo más y más la atención de los investigadores
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