229 research outputs found
Regulación coordinada de los genes implicados en la síntesis de fenilalanina en pino
Regulación coordinada de los genes implicados en la síntesis de Fenilalanina en pino
Craven-Bartle B, Pascual MB, Cánovas FM, Avila C
Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Campus Universitario de Teatinos, Universidad de Málaga, 29071-Málaga, España
([email protected])
Durante el ciclo vital de coníferas como el pino marítimo (Pinus pinaster Ait.) una gran cantidad de esqueletos carbonados se ven inmovilizados de forma irreversible en la madera. Este es un proceso muy costoso en términos energéticos en el que el carbono de la fotosíntesis se canaliza a través de la vía del Siquimato para la biosíntesis de los fenilpropanoides. Esta ruta metabólica fundamental está finamente regulada principalmente a través de control de la transcripción, y puesto que la fenilalanina es el precursor para la biosíntesis de los fenilpropanoides, la regulación precisa de la síntesis de fenilalanina y su utilización debe ocurrir simultáneamente. Los tres promotores de los genes que codifican las enzimas, Prefenato Aminotransferasa (PAT), Fenilalanina Amonio Liasa (PAL), y la Glutamina Sintetasa (GS1b), contienen elementos AC que participan en la activación transcripcional mediada por factores de R2R3-Myb. En este trabajo hemos examinado la capacidad de los factores de transcripción R2R3-Myb: Myb1, Myb4 y Myb8 para co-regular la expresión de PAT, PAL y GS1b. Sólo Myb8 es capaz de activar la transcripción de los tres genes. Por otra parte, la expresión de este factor de transcripción es mayor en tejidos lignificados, donde hay una gran demanda de fenilpropanoides. En un experimento de ganancia de función, hemos demostrado que Myb8 puede unirse específicamente un elemento bien conservado tipo AC-II, de ocho nucleótidos de longitud en las regiones promotoras de PAT, PAL y GS1b, activando de ese modo su expresión. Nuestros resultados muestran que Myb8 regula la expresión de estos genes implicados en el metabolismo de la fenilalanina, que se requiere para la canalización de carbono fotosintético para promover la formación de la madera. La co-localización de los tránscritos de PAT, PAL, GS1b y MYB8 en células vasculares también apoya esta conclusión.
Financiado por: Proyecto de excelencia de la Junta de Andalucía (CVI-3739), Proyecto del Ministerio de Ciencia e Innovación (BIO2009-07490) y por el programa KBBE Plant (proyecto SUSTAINPINE)Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Root and shoot growth of Pinus strobus x P. wallichiana somatic plants is influenced by the nitrogen composition of the germination medium
Somatic embryogenesis (SE) in conifers has proven to be an useful biotechnological tool for
species conservation and mass propagation, but to make it commercially viable, adaptive
research is required to convert laboratory protocols into plantation reality. Hybrid white pines
are of interest to forest industry in North America due to the potential resistance to white pine
blister rust (Cronartium ribicola). Somatic embryos of many pine species are typically
germinated on the same nutrient medium as used for earlier stages of SE. For most of the
genotypes of white and hybrid white pine, the time required for the plantlets to grow a 2 cm
root takes approximately five to six months at which time the plantlets can be potted and
transferred to a greenhouse. The survival of plants is however sketchy and not always reliable.
In order to accelerate and improve the root growth and survival of the plants in a greenhouse a
study was initiated on the manipulation of the nitrogen composition of the germination
medium. We were interested in learning whether the pine somatic seedlings had a preference
for organic or inorganic forms of N during the germination step and root growth. Experiments
have been conducted to determine the uptake and content of 15N in those roots by submerging
them in a hydroponic solution for two hours. The somatic seedlings’ root growth was
dramatically affected by the N composition of the medium as well as it did affect the uptake of
15N. To follow up the nitrogen metabolism in somatic seedlings, we have performed
microarray and qPCR analysis for nitrogen or nitrogen-related metabolism genes. The results
of the analysis will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Nitrogen metabolism in forest trees
NITROGEN METABOLISM IN FOREST TREES
Francisco Cánovas, Concepción Ávila, Fernando N de la Torre, Rafael Cañas, Belén Pascual.
Universidad de Málaga
Email:[email protected]
Forests are essential components of the ecosystems covering approximately one-third of the Earth’s land area and playing a fundamental role in the regulation of terrestrial carbon sinks. Forest trees are also of significant economic importance, as they are used for timber and paper production worldwide. A sustainable management of forest resources is needed to preserve natural forest and to meet the increasing international demands in the production of wood and the other forest-derived products. New advances and developments in biotechnology will contribute to accelerate the domestication of important traits for forest productivity. It is critical to identify the fundamental constraints on forest productivity to addressing these constraints with modern genomic tools. Nitrogen availability extremely low in forest ecosystems, and consequently, forest trees have evolved adaptive mechanism and biotic interactions to guarantee the strict economy of this essential nutrient. Nitrogen assimilation and recycling play a key role in the tree growth and biomass production and we firmly believe that knowledge on nitrogen metabolism will lead to approaches aimed at increasing forest productivity. In our laboratory, we are interested in studying nitrogen metabolism and its regulation the conifer maritime pine (Pinus pinaster Aiton), a forest tree species of great economic and ecological importance in the Mediterranean area and relevant model for conifer genomic research in Europe.
Current research efforts are focused on improving the understanding of the response of conifer trees to ammonium availability and the transcriptional control of ammonium assimilation into amino acids. An overview and update of our research programme will be presented and discussed. Research supported by Spanish Ministry of Economy and Competitiveness and Junta de Andalucía (Grants BIO2012-33797, PLE2009-016 and research group BIO-114).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Influence of Chemical Enhancers and Iontophoresis on the In Vitro Transdermal Permeation of Propranolol: Evaluation by Dermatopharmacokinetics
[EN] The aims of this study were to assess, in vitro, the possibility of administering propranolol transdermally and to evaluate the usefulness of the dermatopharmacokinetic (DPK) method in assessing the transport of drugs through stratum corneum, using propranolol as a model compound. Four chemical enhancers (decenoic and oleic acid, laurocapram, and R-(+)-limonene) and iontophoresis at two current densities, 0.25 and 0.5 mA/cm(2) were tested. R-(+)-limonene, and iontophoresis at 0.5 mA/cm(2) were proven to be the most efficient in increasing propranolol transdermal flux, both doubled the original propranolol transdermal flux. Iontophoresis was demonstrated to be superior than the chemical enhancer because it allowed faster delivery of the drug. The DPK method was sufficiently sensitive to detect subtle vehicle-induced effects on the skin permeation of propranolol. The shorter duration of these experiments and their ability to provide mechanistic information about partition between vehicle and skin and diffusivity through skin place them as practical and potentially insightful approach to quantify and, ultimately, optimize topical bioavailability.This research was funded by Ministerio de Ciencia e Innovación (AP2007-03456) and the Universidad CEU Cardenal Herrera.Calatayud-Pascual, M.; Sebastian-Morelló, M.; Balaguer-Fernandez, C.; Delgado-Charro, M.; Lopez-Castellano, A.; Merino Sanjuán, V. (2018). Influence of Chemical Enhancers and Iontophoresis on the In Vitro Transdermal Permeation of Propranolol: Evaluation by Dermatopharmacokinetics. Pharmaceutics. 10(4):1-15. https://doi.org/10.3390/pharmaceutics10040265S11510
Two-loop corrections to the Isgur-Wise function in QCD sum rules
We complete the QCD sum rule analysis of the Isgur Wise form factor
at next-to-leading order in renormalization-group improved
perturbation theory. To this end, the exact result for the two-loop corrections
to the perturbative contribution is derived using the heavy quark effective
theory. Several techniques for the evaluation of two-loop integrals involving
two different types of heavy quark propagators are discussed in detail, among
them the methods of integration by parts and differential equations. The
order- corrections to the Isgur-Wise function turn out to be small
and well under control. At large recoil, they tend to decrease the form factor
by .Comment: 24 pages (REVTEX), 2 figures available upon request, SLAC-PUB-599
Lower relative differential expression of two genes is associated with delayed ripening in melon
[SPA] Con el fin de comparar la expresión génica de un melón cerca de la línea isogénica (NIL) SC10-2 y su parental Piel de Sapo (PS) durante la maduración y para comprender los mecanismos de diferenciación, se realizó una secuenciación transcriptoma. Dos genes de CmGGP (GDP-L-galactosa fosforilasa 1) y CmRAP2-11 (factor de transcripción sensible al etileno RAP2-11) mostraron menor expresión relativa en la NIL SC10 -2 versus PS debido a la introgresión en LG X. Sin embargo, no existieron diferencias en expresión de CmAP2-like X1 (factor de transcripción sensible al etileno, similar a AP2 TOE3 isoforma X1). En consecuencia, la expresión de genes que mapearon en el grupo de ligamiento X como un factor de transcripción de respuesta a etileno o del metabolismo del ácido ascórbico estuvieron probablemente asociados con el retraso de maduración.
[ENG] The expression of selected genes during ripening was studied considering a melon Near-isogenic Line (NIL) SC10-2 and its parental “Piel de Sapo” (PS). The expression of CmGGP (GDP-L-galactose phosphorylase 1), CmAP2-like X1 (AP2-like ethylene-responsive transcription factor TOE3 isoform X1) and CmRAP2-11 (ethylene-responsive transcription factor RAP2-11) were differentially expressed in the NIL SC10-2 compared with PS. Consequently, expression of genes that mapped in LG X such as one ethylene response transcription factors or ascorbic acid metabolism gene were probably associated with delayed ripening.Financial support: Fundación Séneca de la Región de Murcia (11784/PI/09), MINECO & UE-FEDER funds (AGL2010-20858). Thanks for the technical assistance to P. Varó and his team in CIFEA-Torre Pacheco (Consejería de Agricultura, Región de Murcia) for crop management and IRTA-CRAG for the seeds of the NIL
Density functional method for nonequilibrium electron transport
We describe an ab initio method for calculating the electronic structure,
electronic transport, and forces acting on the atoms, for atomic scale systems
connected to semi-infinite electrodes and with an applied voltage bias. Our
method is based on the density functional theory (DFT) as implemented in the
well tested Siesta approach (which uses non-local norm-conserving
pseudopotentials to describe the effect of the core electrons, and linear
combination of finite-range numerical atomic orbitals to describe the valence
states). We fully deal with the atomistic structure of the whole system,
treating both the contact and the electrodes on the same footing. The effect of
the finite bias (including selfconsistency and the solution of the
electrostatic problem) is taken into account using nonequilibrium Green's
functions. We relate the nonequilibrium Green's function expressions to the
more transparent scheme involving the scattering states. As an illustration,
the method is applied to three systems where we are able to compare our results
to earlier ab initio DFT calculations or experiments, and we point out
differences between this method and existing schemes. The systems considered
are: (1) single atom carbon wires connected to aluminum electrodes with
extended or finite cross section, (2) single atom gold wires, and finally (3)
large carbon nanotube systems with point defects.Comment: 18 pages, 23 figure
Revista de Vertebrados de la Estación Biológica de Doñaña
Comportamiento reproductor del camaleón común (Chamaeleo chamaeleon L.) en el sur de EspañaDistribución de los reptiles en la provincia de Granada (SE. Península Ibérica)Datos sobre la reproducción y el crecimientode Psammodromus hispanicus Fitzinger, 1826 en un medio adehesado de la España CentralVariación en la colocación y orientación del nido del Alzacola (Cercotrichas galactotes) en dos especies de árbolesOrganización de la comunidad de aves reproductora en las landas montanas del País Vasco AtlánticoEcología de una población ibérica de lobos (Canis Lupus)Etude biométrique des Crosidures (Soricidae, Insectivora) de la región de Massa (Souss, Maroe).Variación geográfica del género Eliomys en la Península IbéricaTendencias gregarias del Ciervo (Cervus elaphus) en Doñana.Data on the autumn diet of the red deer (Cervus elaphus L. 1758) in the Montes de Toledo (Central Spain)Nota sobre la coexistencia de Hyla arborea (L. 1758E Hyla meridionalis (Boettger 1874) rn rl Valle del TiétarCalendario reproductivo y tamaño de las puesta en el galápago leproso, Mauremys leprosa (Shweigger, 1812), en Doñana, HuelvaPelícola (Felicola) inaqualis Piager, 1880 (MALLOPHAGA:TRICHODECTIDAE) parásito deE Herpestes ichneumon L (CARNIVORA: HERPESTIDAE)Abundancia y amplitud de los desplazamientos de Apodemus sylvaticus en cuatro biotopos de Doñana que difieren en cobertura vegetalPeer reviewe
Assessment of plasma chitotriosidase activity, CCL18/PARC concentration and NP-C suspicion index in the diagnosis of Niemann-Pick disease type C: A prospective observational study
Background: Niemann-Pick disease type C (NP-C) is a rare, autosomal recessive neurodegenerative disease caused by mutations in either the NPC1 or NPC2 genes. The diagnosis of NP-C remains challenging due to the non-specific, heterogeneous nature of signs/symptoms. This study assessed the utility of plasma chitotriosidase (ChT) and Chemokine (C-C motif) ligand 18 (CCL18)/pulmonary and activation-regulated chemokine (PARC) in conjunction with the NP-C suspicion index (NP-C SI) for guiding confirmatory laboratory testing in patients with suspected NP-C. Methods: In a prospective observational cohort study, incorporating a retrospective determination of NP-C SI scores, two different diagnostic approaches were applied in two separate groups of unrelated patients from 51 Spanish medical centers (n = 118 in both groups). From Jan 2010 to Apr 2012 (Period 1), patients with =2 clinical signs/symptoms of NP-C were considered ''suspected NP-C'' cases, and NPC1/NPC2 sequencing, plasma chitotriosidase (ChT), CCL18/PARC and sphingomyelinase levels were assessed. Based on findings in Period 1, plasma ChT and CCL18/PARC, and NP-C SI prediction scores were determined in a second group of patients between May 2012 and Apr 2014 (Period 2), and NPC1 and NPC2 were sequenced only in those with elevated ChT and/or elevated CCL18/PARC and/or NP-C SI =70. Filipin staining and 7-ketocholesterol (7-KC) measurements were performed in all patients with NP-C gene mutations, where possible. Results: In total across Periods 1 and 2, 10/236 (4%) patients had a confirmed diagnosis o NP-C based on gene sequencing (5/118 4.2%] in each Period): all of these patients had two causal NPC1 mutations. Single mutant NPC1 alleles were detected in 8/236 (3%) patients, overall. Positive filipin staining results comprised three classical and five variant biochemical phenotypes. No NPC2 mutations were detected. All patients with NPC1 mutations had high ChT activity, high CCL18/PARC concentrations and/or NP-C SI scores =70. Plasma 7-KC was higher than control cut-off values in all patients with two NPC1 mutations, and in the majority of patients with single mutations. Family studies identified three further NP-C patients. Conclusion: This approach may be very useful for laboratories that do not have mass spectrometry facilities and therefore, they cannot use other NP-C biomarkers for diagnosis
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