91 research outputs found
Adicion de la figura de la adopcion internacional en el Codigo civil del estado de Guerrero
No full textOverlapping and specialized roles of tomato phytoene synthases in carotenoid and abscisic acid production
No full textCarotenoids are plastidial isoprenoids required for photoprotection and phytohormone production in all plants. In tomato (Solanum lycopersicum), carotenoids also provide color to flowers and ripe fruit. Phytoene synthase (PSY) catalyzes the first and main flux-controlling step of the carotenoid pathway. Three genes encoding PSY isoforms are present in tomato, PSY1 to PSY3. Mutants have shown that PSY1 is the isoform providing carotenoids for fruit pigmentation, but it is dispensable in photosynthetic tissues. No mutants are available for PSY2 or PSY3, but their expression profiles suggest a main role for PSY2 in leaves and PSY3 in roots. To further investigate isoform specialization with genetic tools, we created gene-edited lines defective in PSY1 and PSY2 in the MicroTom background. The albino phenotype of lines lacking both PSY1 and PSY2 confirmed that PSY3 does not contribute to carotenoid biosynthesis in shoot tissues. Our work further showed that carotenoid production in tomato shoots relies on both PSY1 and PSY2 but with different contributions in different tissues. PSY2 is the main isoform for carotenoid biosynthesis in leaf chloroplasts, but PSY1 is also important in response to high light. PSY2 also contributes to carotenoid production in flower petals and, to a lesser extent, fruit chromoplasts. Most interestingly, our results demonstrate that fruit growth is controlled by abscisic acid (ABA) specifically produced in the pericarp from PSY1-derived carotenoid precursors, whereas PSY2 is the main isoform associated with ABA synthesis in seeds and salt-stressed roots.This work was funded by grants from Spanish Agencia Estatal de Investigación MCIN/AEI /10.13039/501100011033 and European Commission NextGeneration EU/PRTR and PRIMA programs to M.R.-C. (PID2020-115810GB-I00 and UToPIQ-PCI2021-121941). M.R.-C. is also supported by Consejo Superior de Investigaciones Cientificas (202040E299) and Generalitat Valenciana (PROMETEU/2021/056 and AGROALNEXT/2022/067). M.E. and E.B.-E. received predoctoral fellowships from MCIN/AEI (BES-2017-080652) and Colombia’s Colciencias Doctorado Exterior program (MINCIENCIAS885/2020), respectively.Peer reviewe
Arabidopsis FIBRILLIN6 influences carotenoid biosynthesis by directly promoting phytoene synthase activity
No full text© The Author(s) 2023. Published by Oxford University Press on behalf of American Society of Plant Biologists. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact [email protected] are health-promoting plastidial isoprenoids with essential functions in plants as photoprotectants and photosynthetic pigments in chloroplasts. They also accumulate in specialized plastids named chromoplasts, providing color to non-photosynthetic tissues such as flower petals and ripe fruit. Carotenoid accumulation in chromoplasts requires specialized structures and proteins such as fibrillins (FBNs). The FBN family includes structural components of carotenoid sequestering structures in chromoplasts and members with metabolic roles in chloroplasts and other plastid types. However, the association of FBNs with carotenoids in plastids other than chromoplasts has remained unexplored. Here, we show that Arabidopsis (Arabidopsis thaliana) FBN6 interacts with phytoene synthase (PSY), the first enzyme of the carotenoid pathway. FBN6, but not FBN4 (a FBN that does not interact with PSY), enhances the activity of plant PSY (but not of the bacterial PSY crtB) in Escherichia coli cells. Overexpression of FBN6 in Nicotiana benthamiana leaves results in a higher production of phytoene, the product of PSY activity, whereas loss of FBN6 activity in Arabidopsis mutants dramatically reduces the production of carotenoids during seedling de-etiolation and after exposure to high light. Our work hence demonstrates that FBNs promote not only the accumulation of carotenoids in chromoplasts but also their biosynthesis in chloroplasts.This work was funded by grants from Spanish MCIN/AEI/10.13039/501100011033 and European NextGeneration EU/PRTR and PRIMA programs to M.R.-C. (PID2020-115810GB-I00 and UToPIQ-PCI2021-121941). M.R.-C. is also supported by Generalitat Valenciana (PROMETEU/2021/056 and AGROALNEXT/2022/067). Our group is a member of CaRed (Spanish Carotenoid Network) funded by MCIN/AEI (RED2022-134577-T). A.I.-S. and J.N.-C. received predoctoral fellowships from MCIN/AEI (PRE2018-083610 and PRE2021-098681, respectively).Peer reviewe
Cre-LoxP-regulated expression of monoclonal antibodies driven by an ovalbumin promoter in primary oviduct cells
No full textAbstract Background A promoter capable of driving high-level transgene expression in oviduct cells is important for developing transgenic chickens capable of producing therapeutic proteins, including monoclonal antibodies (mAbs), in the whites of laid eggs. Ovalbumin promoters can be used as oviduct-specific regulatory sequences in transgenic chickens, but their promoter activities are not high, according to previous reports. Results In this study, while using a previously characterized ovalbumin promoter, we attempted to improve the expression level of mAbs using a Cre/loxP-mediated conditional excision system. We constructed a therapeutic mAb expression vector, pBS-DS-hIgG, driven by the CMV and CAG promoters, in which the expression of the heavy and light chains of humanized immunoglobulin G (hIgG) is preceded by two floxed stuffer reporter genes. In the presence of Cre, the stuffer genes were precisely excised and hIgG expression was induced in pBS-DS-hIgG-transfected 293T cells. In chicken oviduct primary culture cells, hIgG was expressed after transfection of pBS-DS-hIgG together with the ovalbumin promoter-driven Cre expression vector. The expression level of hIgG in these cells was increased 40-fold over that induced directly by the ovalbumin promoter. On the other hand, hIgG was not induced by the ovalbumin promoter-driven Cre in chicken embryonic fibroblast cells. Conclusions The Cre/loxP-based system could significantly increase ovalbumin promoter-driven production of proteins of interest, specifically in oviduct cells. This expression system could be useful for producing therapeutic mAbs at high level using transgenic chickens as bioreactors.</p
Specific sets of geranylgeranyl diphosphate synthases and phytoene synthases control the production of carotenoids and ABA in different tomato tissues
No full textPlant carotenoids are plastid-synthesized isoprenoids with roles as photoprotectants, pigments, and precursors of bioactive molecules such as the hormone abscisic acid (ABA). The first step of the carotenoid biosynthesis pathway is the production of phytoene from geranylgeranyl diphosphate (GGPP), catalyzed by phytoene synthase (PSY). GGPP produced by plastidial GGPP synthases (GGPPS) is channeled to the carotenoid pathway by direct interaction of GGPPS and PSY enzymes. Three plastid-localized GGPPS isoforms (referred to as SlG1-3) and three PSY enzymes (PSY1-3) are present in tomato (Solanum lycopersicum). Our previous work showed that SlG1 and PSY3 function together in the roots, whereas the rest of the isoforms are required in aerial tissues. Here we generated and analyzed combinations of double mutants lacking PSY1 or PSY2 and SlG2 or SlG3 to investigate the contribution of specific GGPPS and PSY pairs to the production of carotenoids and ABA in different tissues of the tomato plant. Despite that the loss of individual enzymes was found to trigger compensatory mechanisms that complicate interpretation of the results, the results confirm a major role for SlG3 in providing GGPP to PSY2 for housekeeping carotenoid biosynthesis in leaves, whereas SlG2 and PSY1 become most relevant when a more active production is required in flowers and breaker fruits, i.e., at the onset of ripening. We could also confirm that ABA production in the fruit pericarp is more dependent on PSY1 activity than on total carotenoid levels and that fruit size correlates with ABA levels accumulated in ripe rather than breaker fruits
Relationship among research collaboration, number of documents and number of citations. A case study in Spanish computer science production in 2000-2009.
No full textThis paper analyzes the relationship among research collaboration, number of documents and number of citations of computer science research activity. It analyzes the number of documents and citations and how they vary by number of authors. They are also analyzed (according to author set cardinality) under different circumstances, that is, when documents are written in different types of collaboration, when documents are published in different document types, when documents are published in different computer science subdisciplines, and, finally, when documents are published by journals with different impact factor quartiles. To investigate the above relationships, this paper analyzes the publications listed in the Web of Science and produced by active Spanish university professors between 2000 and 2009, working in the computer science field. Analyzing all documents, we show that the highest percentage of documents are published by three authors, whereas single-authored documents account for the lowest percentage. By number of citations, there is no positive association between the author cardinality and citation impact. Statistical tests show that documents written by two authors receive more citations per document and year than documents published by more authors. In contrast, results do not show statistically significant differences between documents published by two authors and one author. The research findings suggest that international collaboration results on average in publications with higher citation rates than national and institutional collaborations. We also find differences regarding citation rates between journals and conferences, across different computer science subdisciplines and journal quartiles as expected. Finally, our impression is that the collaborative level (number of authors per document) will increase in the coming years, and documents published by three or four authors will be the trend in computer science literature
Zebrafish IκB Kinase 1 Negatively Regulates NF-κB Activity
No full textSummaryThe IκB kinase (IKK) activity is critical for processing IκB inhibitory proteins and activating the NF-κB signaling, which is involved in a series of physiological and developmental steps in vertebrates [1–4]. The IKK activity resides in two catalytic subunits, IKK1 and IKK2, and two regulatory subunits, NEMO and ELKS [5–8]. IKK2 is the major cytokine-responsive IκB kinase [9–11] because depletion of IKK1 does not interfere with the IKK activity [12–14]. In fact, IKK1−/− mice display morphological abnormalities that are independent of its kinase activity and NF-κB activation [12–14]. Hence, using zebrafish (Danio rerio) as a model, we examined the evolutionary role of IKK1 in modulating NF-κB. Ikk1−/− zebrafish embryos present head and tail malformations and, surprisingly, show upregulation of NF-κB-responsive genes and increased NF-κB-dependent apoptosis. Overexpression of ikk1 leads to midline structure defects that resemble NF-κB blockage in vivo [1]. Zebrafish Ikk1 forms complexes with NEMO that represses NF-κB in vertebrate cells. Indeed, truncation of its NEMO binding domain (NBD) restores NF-κB-dependent transcriptional activity and, consequently, the ikk1-overexpressing phenotype. Here, we report that Ikk1 negatively regulates NF-κB by sequestering NEMO from active IKK complexes, indicating that IKK1 can function as a repressor of NF-κB
The generation of kidney organoids by differentiation of human pluripotent cells to ureteric bud progenitor-like cells
No full textInternational audienceThis protocol presents recently developed methodologies for the differentiation of human pluripotent stem cells (hPSCs) into ureteric bud (UB) progenitor-like cells. Differentiation of human PSCs to UB progenitor-like cells allows for the generation of chimeric kidney cultures in which the human cells can self-assemble into chimeric 3D structures in combination with embryonic mouse kidney cells over a period of 18 d. UB progenitor-like cells are generated by a two-step process that combines in vitro commitment of human PSCs, whether embryonic stem cells (ESCs) or induced PSCs (iPSCs), under chemically defined culture conditions, with ex vivo cultures for the induction of 3D organogenesis. The models described here provide new opportunities for investigating human kidney development, modeling disease, evaluating regenerative medicine strategies, as well as for toxicology studies
A shade-hyposensitive tomato line shows altered auxin homeostasis and higher fruit yield under high-density field conditions
No full text[EN] Plants detect the presence of nearby vegetation as a reduced ratio of red to far-red light (low R : FR). This proximity shade signal can be simulated in the lab by supplementing white light (W) with FR (W + FR). While shade avoidance strategies are considered undesirable in agricultural crops, FR supplementation enhances plant growth and fruit quality in tomato (Solanum lycopersicum). Here we compared the response of different tomato genotypes to W + FR in the lab and identified one Solanum pennellii introgression line (IL2-2) with a shade-tolerant phenotype at the seedling stage. Compared to the shade-avoider parental genotype M82, IL2-2 plants showed reduced elongation upon W + FR exposure and a disrupted expression of auxin-related genes both under W and W + FR. At harvest, W + FR treatment improved M82 fruit quality by increasing degrees Brix, ascorbic acid, and carotenoids, and these quality traits remained virtually unchanged in IL2-2. Under high density (HD) conditions, fruit quality traits were hardly impacted by planting density or genotype, but IL2-2 showed improved fruit yield. Our findings suggest that IL2-2 could serve as a valuable genotype for high-density or intercropping agrosystems.We thank the staff at the IBMCP Metabolomics Platform for technical support. This study was part of the PRIMA project UToPIQ funded by the Italian Ministero dell'Istruzione e del Merito (MIUR) to MMR (reference E79J21005760001) and the Spanish Agencia Estatal de Investigacion (AEI, MCIN/AEI/10.13039/501100011033) and European Commission NextGeneration EU/PRTR to MR-C (reference PCI2021-121941). Additional funding for MMR and MR-C came from the EU/COST-funded ReCrop network (Reproductive Enhancement of CROP resilience to extreme climate, CA22157). We also acknowledge the support of MICIN/AEI grants PID2020-115810GB-I00, RED2022-134577-T and PID2023-149584NB-I00 to MR-C and PID2020-115782GB-I00, PLEC2022-009323, and PID2023-149395NB-I00 to JFM-G and Generalitat Valenciana grants AGROALNEXT/2022/067 to MR-C and PROMETEU/2021/056 to JFM-G. EB-E received a predoctoral fellowship from Colombia's Colciencias Doctorado Exterior program (MINCIENCIAS885/2020). JP-R is supported by a predoctoral fellowship from AEI (PRE2021-099195).Burbano-Erazo, E.;Francesca, S.;Simon-Moya, M.;Palau-Rodriguez, Julia;Berdonces, A.;Valverde, L.;Pérez-Beser, J.... (2025). A shade-hyposensitive tomato line shows altered auxin homeostasis and higher fruit yield under high-density field conditions. New Phytologist. 247(6). https://doi.org/10.1111/nph.70384S247
In Vivo Activation of a Conserved MicroRNA Program Induces Mammalian Heart Regeneration
No full textSummaryHeart failure is a leading cause of mortality and morbidity in the developed world, partly because mammals lack the ability to regenerate heart tissue. Whether this is due to evolutionary loss of regenerative mechanisms present in other organisms or to an inability to activate such mechanisms is currently unclear. Here we decipher mechanisms underlying heart regeneration in adult zebrafish and show that the molecular regulators of this response are conserved in mammals. We identified miR-99/100 and Let-7a/c and their protein targets smarca5 and fntb as critical regulators of cardiomyocyte dedifferentiation and heart regeneration in zebrafish. Although human and murine adult cardiomyocytes fail to elicit an endogenous regenerative response after myocardial infarction, we show that in vivo manipulation of this molecular machinery in mice results in cardiomyocyte dedifferentiation and improved heart functionality after injury. These data provide a proof of concept for identifying and activating conserved molecular programs to regenerate the damaged heart
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