Literatura académica sobre el tema "RPE in-Cell"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "RPE in-Cell".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Artículos de revistas sobre el tema "RPE in-Cell"
1
Kuznetsova, Alla V., Alexander M. Kurinov y Maria A. Aleksandrova. "Cell Models to Study Regulation of Cell Transformation in Pathologies of Retinal Pigment Epithelium". Journal of Ophthalmology 2014 (2014): 1–18. http://dx.doi.org/10.1155/2014/801787.
Texto completoResumen
The retinal pigment epithelium (RPE) plays a key role in the development of many eye diseases leading to visual impairment and even blindness. Cell culture models of pathological changes in the RPE make it possible to study factors responsible for these changes and signaling pathways coordinating cellular and molecular mechanisms of cell interactions under pathological conditions. Moreover, they give an opportunity to reveal target cells and develop effective specific treatment for degenerative and dystrophic diseases of the retina. In this review, data are presented on RPE cell sources for culture models, approaches to RPE cell culturing, phenotypic changes of RPE cellsin vitro, the role of signal pathways, and possibilities for their regulation in pathological processes.
2
Marrs, J. A., C. Andersson-Fisone, M. C. Jeong, L. Cohen-Gould, C. Zurzolo, I. R. Nabi, E. Rodriguez-Boulan y W. J. Nelson. "Plasticity in epithelial cell phenotype: modulation by expression of different cadherin cell adhesion molecules." Journal of Cell Biology 129, n.º 2 (15 de abril de 1995): 507–19. http://dx.doi.org/10.1083/jcb.129.2.507.
Texto completoResumen
A primary function of cadherins is to regulate cell adhesion. Here, we demonstrate a broader function of cadherins in the differentiation of specialized epithelial cell phenotypes. In situ, the rat retinal pigment epithelium (RPE) forms cell-cell contacts within its monolayer, and at the apical membrane with the neural retina; Na+, K(+)-ATPase and the membrane cytoskeleton are restricted to the apical membrane. In vitro, RPE cells (RPE-J cell line) express an endogenous cadherin, form adherens junctions and a tight monolayer, but Na+,K(+)-ATPase is localized to both apical and basal-lateral membranes. Expression of E-cadherin in RPE-J cells results in restriction and accumulation of both Na+,K(+)-ATPase and the membrane cytoskeleton at the lateral membrane; these changes correlate with the synthesis of a different ankyrin isoform. In contrast to both RPE in situ and RPE-J cells that do not form desmosomes, E-cadherin expression in RPE-J cells induces accumulation of desmoglein mRNA, and assembly of desmosome-keratin complexes at cell-cell contacts. These results demonstrate that cadherins directly affect epithelial cell phenotype by remodeling the distributions of constitutively expressed proteins and by induced accumulation of specific proteins, which together lead to the generation of structurally and functionally distinct epithelial cell types.
3
Szatmári-Tóth, Mária, Tanja Ilmarinen, Alexandra Mikhailova, Heli Skottman, Anu Kauppinen, Kai Kaarniranta, Endre Kristóf et al. "Human Embryonic Stem Cell-Derived Retinal Pigment Epithelium-Role in Dead Cell Clearance and Inflammation". International Journal of Molecular Sciences 20, n.º 4 (20 de febrero de 2019): 926. http://dx.doi.org/10.3390/ijms20040926.
Texto completoResumen
Inefficient removal of dying retinal pigment epithelial (RPE) cells by professional phagocytes can result in debris formation and development of age-related macular degeneration (AMD). Chronic oxidative stress and inflammation play an important role in AMD pathogenesis. Only a few well-established in vitro phagocytosis assay models exist. We propose human embryonic stem cell-derived-RPE cells as a new model for studying RPE cell removal by professional phagocytes. The characteristics of human embryonic stem cells-derived RPE (hESC-RPE) are similar to native RPEs based on their gene and protein expression profile, integrity, and barrier properties or regarding drug transport. However, no data exist about RPE death modalities and how efficiently dying hESC-RPEs are taken upby macrophages, and whether this process triggers an inflammatory responses. This study demonstrates hESC-RPEs can be induced to undergo anoikis or autophagy-associated cell death due to extracellular matrix detachment or serum deprivation and hydrogen-peroxide co-treatment, respectively, similar to primary human RPEs. Dying hESC-RPEs are efficiently engulfed by macrophages which results in high amounts of IL-6 and IL-8 cytokine release. These findings suggest that the clearance of anoikic and autophagy-associated dying hESC-RPEs can be used as a new model for investigating AMD pathogenesis or for testing the in vivo potential of these cells in stem cell therapy.
4
Daniele, Elena, Lorenzo Bosio, Noor Ahmed Hussain, Barbara Ferrari, Stefano Ferrari, Vanessa Barbaro, Brian McArdle et al. "Denuded Descemet’s membrane supports human embryonic stem cell-derived retinal pigment epithelial cell culture". PLOS ONE 18, n.º 2 (6 de febrero de 2023): e0281404. http://dx.doi.org/10.1371/journal.pone.0281404.
Texto completoResumen
Recent clinical studies suggest that retinal pigment epithelial (RPE) cell replacement therapy may preserve vision in retinal degenerative diseases. Scaffold-based methods are being tested in ongoing clinical trials for delivering pluripotent-derived RPE cells to the back of the eye. The aim of this study was to investigate human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells survival and behaviour on a decellularized Descemet’s Membrane (DM), which may be of clinical relevance in retinal transplantation. DMs were isolated from human donor corneas and treated with thermolysin. The DM surface topology and the efficiency of the denudation method were evaluated by atomic force microscope, scanning electron microscopy and histology. hESC-RPE cells were seeded onto the endothelial-side surface of decellularized DM in order to determine the potential of the membrane to support hESC-RPE cell culture, alongside maintaining their viability. Integrity of the hESC-RPE monolayer was assessed by measuring transepithelial resistance. RPE-specific gene expression and growth factors secretion were assessed to confirm maturation and functionality of the cells over the new substrate. Thermolysin treatment did not affect the integrity of the tissue, thus ensuring a reliable method to standardize the preparation of decellularized DM. 24 hours post-seeding, hESC-RPE cell attachment and initial proliferation rate over the denuded DM were higher than hESC-RPE cells cultured on tissue culture inserts. On the new matrix, hESC-RPE cells succeeded in forming an intact monolayer with mature tight junctions. The resulting cell culture showed characteristic RPE cell morphology and proper protein localization. Gene expression analysis and VEGF secretion demonstrate DM provides supportive scaffolding and inductive properties to enhance hESC-RPE cells maturation. Decellularized DM was shown to be capable of sustaining hESC-RPE cells culture, thus confirming to be potentially a suitable candidate for retinal cell therapy.
5
Kindzelskii, Andrei L., Victor M. Elner, Susan G. Elner, Dongli Yang, Bret A. Hughes y Howard R. Petty. "Toll-Like Receptor 4 (TLR4) of Retinal Pigment Epithelial Cells Participates in Transmembrane Signaling in Response to Photoreceptor Outer Segments". Journal of General Physiology 124, n.º 2 (26 de julio de 2004): 139–49. http://dx.doi.org/10.1085/jgp.200409062.
Texto completoResumen
Retinal pigment epithelial (RPE) cells mediate the recognition and clearance of effete photoreceptor outer segments (POS), a process central to the maintenance of normal vision. Given the emerging importance of Toll-like receptors (TLRs) in transmembrane signaling in response to invading pathogens as well as endogenous substances, we hypothesized that TLRs are associated with RPE cell management of POS. TLR4 clusters on human RPE cells in response to human, but not bovine, POS. However, TLR4 clustering could be inhibited by saturating concentrations of an inhibitory anti-TLR4 mAb. Furthermore, human POS binding to human RPE cells elicited transmembrane metabolic and calcium signals within RPE cells, which could be blocked by saturating doses of an inhibitory anti-TLR4 mAb. However, the heterologous combination of bovine POS and human RPE did not trigger these signals. The pattern recognition receptor CD36 collected at the POS–RPE cell interface for both homologous and heterologous samples, but human TLR4 only collected at the human POS–human RPE cell interface. Kinetic experiments of human POS binding to human RPE cells revealed that CD36 arrives at the POS–RPE interface followed by TLR4 accumulation within 2 min. Metabolic and calcium signals immediately follow. Similarly, the production of reactive oxygen metabolites (ROMs) was observed for the homologous human system, but not the heterologous bovine POS–human RPE cell system. As (a) the bovine POS/human RPE combination did not elicit TLR4 accumulation, RPE signaling, or ROM release, (b) TLR4 arrives at the POS–RPE cell interface just before signaling, (c) TLR4 blockade with an inhibitory anti-TLR4 mAb inhibited TLR4 clustering, signaling, and ROM release in the human POS–human RPE system, and (d) TLR4 demonstrates similar clustering and signaling responses to POS in confluent RPE monolayers, we suggest that TLR4 of RPE cells participates in transmembrane signaling events that contribute to the management of human POS.
6
Voisin, Audrey, Christelle Monville, Alexandra Plancheron, Emile Béré, Afsaneh Gaillard y Nicolas Leveziel. "Cathepsin B pH-Dependent Activity Is Involved in Lysosomal Dysregulation in Atrophic Age-Related Macular Degeneration". Oxidative Medicine and Cellular Longevity 2019 (6 de diciembre de 2019): 1–15. http://dx.doi.org/10.1155/2019/5637075.
Texto completoResumen
Age-related macular degeneration (AMD) is characterized by retinal pigment epithelial (RPE) cell dysfunction beginning at early stages of the disease. The lack of an appropriate in vitro model is a major limitation in understanding the mechanisms leading to the occurrence of AMD. This study compared human-induced pluripotent stem cell- (hiPSC-) RPE cells derived from atrophic AMD patients (77 y/o±7) to hiPSC-RPE cells derived from healthy elderly individuals with no drusen or pigmentary alteration (62.5 y/o±17.5). Control and AMD hiPSC-RPE cell lines were characterized by immunofluorescence, flow cytometry, and electronic microscopy. The toxicity level of iron after Fe-NTA treatment was evaluated by an MTT test and by the detection of dichloro-dihydro-fluorescein diacetate. Twelve hiPSC-RPE cell lines (6 AMD and 6 controls) were used for the experiment. Under basal conditions, all hiPSC-RPE cells expressed a phenotypic profile of senescent cells with rounded mitochondria at passage 2. However, the treatment with Fe-NTA induced higher reactive oxygen species production and cell death in hiPSC-RPE AMD cells than in hiPSC-RPE Control cells. Interestingly, functional analysis showed differences in lysosomal activity between the two populations. Indeed, Cathepsin B activity was higher in hiPSC-RPE AMD cells compared to hiPSC-RPE Control cells in basal condition and link to a pH more acidic in this cell population. Moreover, oxidative stress exposure leads to an increase of Cathepsin D immature form levels in both populations, but in a higher proportion in hiPSC-RPE AMD cells. These findings could demonstrate that hiPSC-RPE AMD cells have a typical disease phenotype compared to hiPSC-RPE Control cells.
7
Arai, Rei, Ayumi Usui-Ouchi, Yosuke Ito, Keitaro Mashimo, Akira Murakami y Nobuyuki Ebihara. "Effects of Secreted Mast Cell Mediators on Retinal Pigment Epithelial Cells: Focus on Mast Cell Tryptase". Mediators of Inflammation 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/3124753.
Texto completoResumen
Numerous mast cells are present in the choroid, but the effects of mast cell mediators on retinal pigment epithelial (RPE) cells are not well understood. We investigated the influence of mast cell mediators on RPE cells in vitro, focusing on tryptase. Expression of receptors was examined by the reverse transcription polymerase chain reaction. We also assessed production of interleukin 8 and vascular endothelial growth factor (VEGF) after RPE cells were stimulated with mast cell mediators by using an antibody array and enzyme-linked immunosorbent assay. Furthermore, we investigated the influence of tryptase on RPE cell migration and integrity by the scratch assay and the transepithelial resistance. RPE cells expressed protease-activated receptor 2 (PAR2), histamine receptor 1, tumor necrosis factor-α (TNF-α) receptor 1, and CCR 1, 3, 4, 8, and 11. Tryptase, PAR2 agonists, histamine, and TNF-α all enhanced interleukin 8 production by RPE cells, while only tryptase enhanced VEGF production. Tryptase also enhanced expression of phosphorylated extracellular signal-regulated kinases 1/2, resulting in increased migration of RPE cells. However, tryptase did not alter epithelial integrity or the expression of zonula occludens-1 and junctional adhesion molecule-A by RPE cells. Mast cell mediators, especially tryptase, may influence RPE cell inflammation.
8
Hellinen, Laura, Heidi Hongisto, Eva Ramsay, Kai Kaarniranta, Kati-Sisko Vellonen, Heli Skottman y Marika Ruponen. "Drug Flux Across RPE Cell Models: The Hunt for An Appropriate Outer Blood–Retinal Barrier Model for Use in Early Drug Discovery". Pharmaceutics 12, n.º 2 (19 de febrero de 2020): 176. http://dx.doi.org/10.3390/pharmaceutics12020176.
Texto completoResumen
The retinal pigment epithelial (RPE) cell monolayer forms the outer blood–retinal barrier and has a crucial role in ocular pharmacokinetics. Although several RPE cell models are available, there have been no systematic comparisons of their barrier properties with respect to drug permeability. We compared the barrier properties of several RPE secondary cell lines (ARPE19, ARPE19mel, and LEPI) and both primary (hfRPE) and stem-cell derived RPE (hESC-RPE) cells by investigating the permeability of nine drugs (aztreonam, ciprofloxacin, dexamethasone, fluconazole, ganciclovir, ketorolac, methotrexate, voriconazole, and quinidine) across cell monolayers. ARPE19, ARPE19mel, and hfRPE cells displayed a narrow Papp value range, with relatively high permeation rates (5.2–26 × 10−6 cm/s. In contrast, hESC-RPE and LEPI cells efficiently restricted the drug flux, and displayed even lower Papp values than those reported for bovine RPE-choroid, with the range of 0.4–32 cm−6/s (hESC-RPE cells) and 0.4–29 × 10−6 cm/s, (LEPI cells). Therefore, ARPE19, ARPE19mel, and hfRPE cells failed to form a tight barrier, whereas hESC-RPE and LEPI cells restricted the drug flux to a similar extent as bovine RPE-choroid. Therefore, LEPI and hESC-RPE cells are valuable tools in ocular drug discovery.
9
Gupta, Santosh, Lyubomyr Lytvynchuk, Taras Ardan, Hana Studenovska, Georgina Faura, Lars Eide, Ljubo Znaor et al. "Retinal Pigment Epithelium Cell Development: Extrapolating Basic Biology to Stem Cell Research". Biomedicines 11, n.º 2 (23 de enero de 2023): 310. http://dx.doi.org/10.3390/biomedicines11020310.
Texto completoResumen
The retinal pigment epithelium (RPE) forms an important cellular monolayer, which contributes to the normal physiology of the eye. Damage to the RPE leads to the development of degenerative diseases, such as age-related macular degeneration (AMD). Apart from acting as a physical barrier between the retina and choroidal blood vessels, the RPE is crucial in maintaining photoreceptor (PR) and visual functions. Current clinical intervention to treat early stages of AMD includes stem cell-derived RPE transplantation, which is still in its early stages of evolution. Therefore, it becomes essential to derive RPEs which are functional and exhibit features as observed in native human RPE cells. The conventional strategy is to use the knowledge obtained from developmental studies using various animal models and stem cell-based exploratory studies to understand RPE biogenies and developmental trajectory. This article emphasises such studies and aims to present a comprehensive understanding of the basic biology, including the genetics and molecular pathways of RPE development. It encompasses basic developmental biology and stem cell-based developmental studies to uncover RPE differentiation. Knowledge of the in utero developmental cues provides an inclusive methodology required for deriving RPEs using stem cells.
10
Kamao, Hiroyuki, Atsushi Miki y Junichi Kiryu. "ROCK Inhibitor-Induced Promotion of Retinal Pigment Epithelial Cell Motility during Wound Healing". Journal of Ophthalmology 2019 (19 de junio de 2019): 1–10. http://dx.doi.org/10.1155/2019/9428738.
Texto completoResumen
Purpose. No standard therapy for RPE tear, a complication of neovascular age-related macular degeneration, exists even though RPE tears cause severe vision loss, and promotion of cell proliferation and/or migration could be a candidate RPE tear therapy. The aim of this study is to evaluate the effect of Rho-associated coiled-coil containing kinase (ROCK) inhibitor Y27632 on retinal pigment epithelial (RPE) cell motility during wound healing. Methods. Human RPE cells were cultured in media with and without 10 μM Y27632. A luminescent cell viability assay and vinculin immunocytochemistry were used to test the Y27632 effect on RPE cell adhesion. The mean size of vinculin puncta was quantified from immunofluorescence images. RPE cell motility during wound healing was evaluated using time-lapse imaging and measuring cell migration distances and cell coverage rate in wound fields. Results. The number of adhered RPE and mean size of vinculin puncta were, respectively, 20519 cells and 3.65 μm2 under nontreatment and 23569 cells and 0.66 μm2 under Y27632 treatment. Cell migration distance and cell coverage percentage for untreated and Y27632-treated cells were 98.9 and 59.4% and 203.4 and 92.5%, respectively. Conclusions. Inhibition of ROCK signaling by using 10 μM Y27632 promoted RPE cell motility during wound healing by reducing RPE cell adhesion strength.
Tesis sobre el tema "RPE in-Cell"
1
Spencer, Samantha A. "The Role of tfec in Zebrafish Neural Crest Cell and RPE Development". VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3754.
Texto completoResumen
Zebrafish (Danio rerio) show a unique pigmentation pattern comprised of three pigment cell types: melanophores, iridophores and xanthophores. Other pigmented cells include the retinal pigmented epithelium (rpe) which absorbs excess light in the eye and maintain the extracellular environment around the photoreceptors. While previous mutations in mitfa showed a role in regulating trunk melanophores, the rpe was not affected. TALENs and CRISPR-Cas9 systems were used to generate mutant zebrafish for tfec, a transcription factor expressed in both neural crest and rpe. Embryos with tfec mutations showed a loss of iridophore pigmentation, and delays in the pigmentation of xanthophores and rpe, showing positive regulation of multiple pigment cells. Double mutants for tfec and mitfa displayed greater losses of iridophore, xanthophore and rpe pigmentation with noncircular globes, suggesting cooperative roles for these transcription factors.
2
Gentles, Jeremy A., William G. Hornsby, Howard S. Gray, Jonathan A. Miller, Andy R. Dotterweich, Charles A. Stuart y Michael H. Stone. "Changes in Cell Free DNA During a College Soccer Season". Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etsu-works/3795.
Texto completoResumen
Objectives: This study investigated chronic changes in cell free DNA (cf-DNA) throughout a collegiate soccer season. The relationship between cf-DNA, C-reactive protein (CRP), creatine kinase (CK), testosterone (T), cortisol (C), testosterone-cortisol ratio (T:C), body mass and body composition were also examined. Design: Longitudinal study design with repeated measures and group comparisons.Methods: Twenty three NCAA Division I male soccer players were divided into two groups. Starters were placed in Group 1 (G1) and non-starters were placed in Group 2 (G2). cf-DNA, CRP, CK, T, C, T:C, body mass and body composition were taken three times, corresponding to pre-season, approximately mid-season and immediately after the concluding the season.Results: In G1, cf-DNA, CRP, CK, cf-DNA %∆, CRP %∆ and, CK %∆ were all statistically higher at T2 and T3 than T1. In G2, CRP %∆ was statistically higher at T2 than T1. In G2, cf-DNA %∆, CRP %∆ and CK %∆ were higher at T2 and T3 than T1.Conclusions: This suggests that cf-DNA may be a useful marker that can reflect accumulated soccer training and competitive stressors.
3
Pierro, Annalisa. "Protein structural dynamics in bacteria via nitroxide-based SDSL-EPR spectroscopy : from method improvements to in-cell studies". Electronic Thesis or Diss., Aix-Marseille, 2021. http://theses.univ-amu.fr.lama.univ-amu.fr/211116_PIERRO_290xrxu60ryzjfl293g970fjmdnl_TH%20(1).pdf.
Texto completoResumen
L'étude des biomolécules dans leur environnement natif, la cellule, est l'un des principaux objectifs de la biologie structurale au cours de la dernière décennie. Ainsi, nous assistons à un remarquable développement des approches dites « in-cell », comme la CryoET, FRET (Förster Resonance Energy Tranfer), RMN. Parmi elles, la technique de marquage de spin couplée à la spectroscopie de Résonance Paramagnétique Electronique (SDSL-RPE) présente des caractéristiques intéressantes et avantageuses permettant de sonder la dynamique des protéines à l'intérieur des cellules. En particulier, l’utilisation des sondes de type nitroxyde combine sensibilité élevée et absence de contraintes de taille de la biomolécule d'intérêt avec la capacité d'étudier les transitions structurales et les interactions protéines-protéines à température physiologique. Cependant, même si de nombreux efforts ont été faits pour adapter cette technique à des études structurales dans les cellules, des progrès restent à faire.Dans cette thèse, nous traitons des principales limitations de l’utilisation des nitroxydes dans un contexte cellulaire. Nous nous sommes concentrés sur la stabilité des marqueurs nitroxydes dans des milieux reducteurs et dans la cellule, sur l’incorporation des protéines marquées dans les cellules et la viabilité de ces cellules en vue de mesures par RPE. Grâce aux résultats obtenus dans cette partie méthodologique, nous avons pu étudier la dynamique structurale de deux protéines chaperons (NarJ et UreG) dans des cellules bactériennes. Ces avancées ont permis de comparer les données obtenues in-cell à celles obtenues in vitro ou dans un environnement mimant le milieu cellulaireThe study of biomolecules in their native environment has been one of the main goals of structural biology in the last decade. As a result, we are assisting to a remarkable increase of new "in-cell" approaches, like Cryo-ET, FRET and NMR. Among these approaches, Site-Directed Spin Labeling (SDSL) coupled to Electron Paramagnetic Resonance (EPR) spectroscopy shows competitive and advantageous features to capture protein dynamics inside cells. In particular, nitroxide-based SDSL-EPR combines the advantages of high sensitivity and the lack of size constraints on the biomolecule of interest with the ability to capture protein structural transitions and interactions at physiological temperature. Despite the methodological advancements of the technique that have allowed the community to obtain increasingly relevant results, progresses still need to be done.In this work, the main limitation of nitroxide-based SDSL-EPR has been addressed. In the first time, we focused on the development of delivery methods to introduce the labeled protein in bacterial cells. Next, the stability of nitroxide labels in reducing environments and in-cell has been assessed, monitoring in parallel the viability of the cells during the EPR measurements. Thanks to the results achieved in this methodological part, we were able to study the structural dynamics of two flexible chaperone proteins directly in bacterial cells: NarJ from Escherichia coli and UreG from Sporosarcina pasteurii. Finally, to go further in understanding the impact of the cellular environment on the protein dynamics, the data obtained in cellular context were compared with those obtained in vitro or in a cell-mimicking environment
4
Guo, Shuangli. "ROLE OF REPLICATION PROTEIN A (RPA) AND PROLIFERATING CELL NUCLEAR ANTIGEN (PCNA) IN DNA MISMATCH REPAIR". UKnowledge, 2005. http://uknowledge.uky.edu/gradschool_diss/258.
Texto completoResumen
PCNA and RPA are required for DNA mismatch repair (MMR), but their rolesin the pathway are not fully understood. Using an affinity pull-down approach, weshow that (1) increased PCNA binding to DNA heteroduplexes is associated withthe appearance and accumulation of excision products; and (2) RPAphosphorylation occurs when DNA polymerase ?? binds to the DNA substrate. Wetherefore hypothesize that PCNA plays an important role in mismatch-provokedexcision and that RPA phosphorylation plays an important role in DNA resynthesis.To determine the role of PCNA in MMR, mismatch-provoked and nick-directedexcision was assayed in a cell-free system in the presence of the PCNA inhibitor,p21CIP1/WAF. We show that whereas PCNA is essential for 3' directed excision, it isdispensable for the 5' directed reaction, suggesting a differential role for PCNA inMMR. We further find that the PCNA-dependent pathway is the only pathway for3' directed excision, but there are at least two pathways for 5' directed excision,one of which is a PCNA-independent 5' excision pathway. To determine if RPAphosphorylation facilitates DNA resynthesis, a gap-filling assay was developedusing both a cell-free system and a purified system, and we demonstrate that RPAphosphorylation stimulates DNA polymerase ??-catalyzed resynthesis in bothsystems. Kinetic studies indicate that phosphorylated RPA has a lower affinity forDNA compared with un-phosphorylated RPA. Therefore, the stimulation ofresynthesis by phosphorylated RPA is likely due to the fact that phosphorylationpromotes the release of RPA from DNA, thereby making DNA template availablefor resynthesis.
5
Guo, Shuangli. "Role of DNA replication proteina (RPA) and proliferating cell nuclear antigen (PCNA) in human DNA mismatch repair". Lexington, Ky. : [University of Kentucky Libraries], 2005. http://lib.uky.edu/ETD/ukybioc2005d00284/etd.pdf.
Texto completoResumen
Thesis (Ph. D.)--University of Kentucky, 2005.Title from document title page (viewed on November 7, 2005). Document formatted into pages; contains x, 3 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 84-92).
6
Davoren, Jonathan M. y University of Lethbridge Faculty of Arts and Science. "Gene expression in a microspore-derived cell suspension culture of Brassica Napus exhibiting enhanced oil production". Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 1997, 1997. http://hdl.handle.net/10133/345.
Texto completoResumen
Triacylglycerol (TAG) production in the microspore derived (MD) cell
suspension culture ofBrassica napus L. cv Jet Neuf was enhanced when the sucrose
concentration in the growth medium was increased from 2 to 14 % (w/v). mRNA
differential display by polymerase chain reaction was used to examine gene expression in
cells grown at different sucrose concentrations in order to identify mRNAs which
could be associated with oil formation. The anchored primer, T12AA, was used to screen
one subset, representing approximately one twelfth of the transcript population, isolated
from cultures grown in media supplemented to 2, 6 and 14 % (w/v) sucrose. Analysis of
this mRNA subset revealed thirteen cDNAs which appeared to be upregulated as the
sucrose concentration was increased. Cloning and sequencing revealed multiple cDNA
fragments for each signal detected by differential display. RT-PCR analysis of sixteen
different cDNAs revealed that eight encoded mRNAs which were upregulated in parallel
to the increase in media sucrose. Comparison of the eight upregulated cDNAs to other
sequences in GenBank revealed the following: (1) BSS8A had a 100% identity with the
last 25 amino acids of an acyl carrier protein from Arabidopsis thaliana, (2) BSS1A
displayed homology to a number of sequences of unknown function, (3) BSS1 IB
displayed weak but significant homology to a number of sequences of unknown function,
(4) BSS13A displayed homology to four members of the thioredoxin family from ,4.
thaliana and (5) four Had no significant homology to previously reported sequences
which makes them potential candidates to encode lipogenic enzymes. These results
indicate that differential display of mRNA may be a simple and rapid method for the
identification of sucrose-modulated gene expression changes in this system and for the
characterization of novel sequences potentially encoding lipogenic proteins.xxi, 256 leaves : ill. ; 28 cm.
7
Pourazadi, Ehsan. "Facile Synthesis of Boron-doped Graphitic Materials for Oxygen Reduction Purpose in Fuel Cell". Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/16032.
Texto completoResumen
Modern civilization is blamed for aggravating climate change as well as global warming by pumping millions of tonnes of greenhouse gases into the atmosphere. In addition to environmental concerns, the ever-increasing energy demand calls for new generations of power technologies to supply such a rapid rise in energy market. Fuel cells show to be placed at the cornerstone of technology development for the current century, since they could mitigate the environmental concern and meet the escalation in energy need. However, transforming to a future sustainable energy with zero to low CO2 emission needs the development of cheap fuel cells on top of a sustainable hydrogen supply. The current scientists’ and engineers’ challenge is the fabrication of cheap, durable and reliable catalyst materials for electrochemical reduction of oxygen in cathode which is a crucial factor in determining cell’s efficiency. We also looked into this area to find new cathodic materials and compared their performance against commonly mentioned materials in literature. The focus of this contribution is to compare the Oxygen Reduction Reaction (ORR) performance of widely literature cited boron-doped graphene materials with the new type of boron-doped samples known as Graphene Organic Framework (GOF). The first chapter deals with the commercialization problem by discussing cell’s internal design, classification and its operation. Subsequently, new alternative suggested substitutes such as metallic nano catalyst, metallic-graphene hybrids, polymeric and new non-metallic graphitic electrocatalysts. The chapter will continue subsequently by introducing GOF material, which are able to form the similar CBO2 structure as the previously literature cited substitutionally boron-doped graphene (BGs) formed, as a novel catalyst for ORR. The second chapter examines the material synthesis and characterization. Three samples of substitutionally boron-doped graphene, identified as BG1, BG2 and BG3, and two types of new porous GOFs materials are synthesised under various preparation strategies. In order to confirm the integration and presence of boron in synthesised samples, variety of characterization and spectroscopic analysis are performed. XRD, TGA and FTIR are exclusively applied to GOF materials since their applications to BG samples will not provide any valuable information. However Raman and XPS characterizations are executed for all samples to determine the degree of G-band shifts (i.e. the extent of doping) and corresponding surface concentration of doped boron. The third chapter provides electrochemical results of prepared materials using conventional CV and RDE techniques in electrochemistry. To complete the discussion, subsequently, the incompetency of Koutchy-Levich (K-L) method and Rotating Disk Electrode (RDE) for determining the true ORR path is explained by reviewing Koutchy-Levich (K-L) method fundamentals. Instead Rotating Ring Disk Electrode (RRDE) technique is considered to estimate the true ORR efficiency of literature materials (BGs) versus introduced GOF substances. Finally Table 3.3 provides a comprehensive review on the results achieved during my electrochemistry analysis including testing the materials in two different laboratory facilities. The fourth chapter investigates the understanding of kinetic reaction of oxygen reduction for synthesised electrode catalysts. This is a work which barely has been considered by previous studies and could be beneficial to find the right application for materials. Based on the corresponding analysis in this chapter, except for commercial 20% Pt/C and Glassy Carbon (GC) electrodes, all materials are leading the ORR through multiple parallel-series steps with reaction constants of k1, k2 and k3 >0. However for cases like BG1 and BG2, the k3 value might be very small and close to zero that we can consider two simultaneous parallel 4e- and 2e- ORR. Finally the fifth chapter gives a summary of all thesis contents including future guides for completing this research study.
8
Wolk, Alyson M. "The Role of the Retinal Pigment Epithelium in Sorsby Fundus Dystrophy". Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1606842751125309.
Texto completo
9
Du, Plessis Peter Clark. "Variations in radiosensitivity of breast cancer and normal breast cell lines using a 200MeV clinical proton beam". Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2970.
Texto completoResumen
Thesis (MSc (Radiography))--Cape Peninsula University of Technology, 2018Background: Breast cancer is one of the most commonly diagnosed among woman in South Africa, and a more resilient effort should be focused on treatment improvements. Worldwide, proton therapy is increasingly used as a radiation treatment alternative to photon therapy for breast cancer, mostly to decrease the risk for radiation-induced cardiovascular toxicity. This in vitro study aims to determine a better understanding of the radiosensitivity of both tumour and normal breast cell lines to clinical proton irradiation. In addition, we propose to investigate whether the increase in linear energy transfer (LET) towards the distal part of the proton beam results in an increase in relative biological effectiveness (RBE) for both cell lines. Methods: Malignant (MCF-7) and non-malignant (MCF-10A) breast cells were irradiated at different water equivalent depths in a 200 MeV proton beam at NRF iThemba LABS using a custom-made Perspex phantom: the entrance plateau, 3 points on the Bragg peak, the D80% and the D40%. A cytokinesis-block Micronucleus (CBMN) assay was performed and Micronuclei (MNi) were manually counted in binucleated cells (BNCs) using fluorescent microscopy. Reference dosimetry was carried out with a Markus chamber and irradiations were performed with a clinical proton beam generated at NRF iThemba LABS that was degraded to a R50 (half-value depths) range of 120 mm, with a field size of 10 cm x 10 cm and a 50 mm SOBP. The phantom could be adjusted to accommodate different perspex plates depending on the depth required within the proton beam. Cells were then exposed to 0.5, 1.0, 2.0, 3.0 and 4.0 Gy doses for each cell line independently and for each dose point. Results and Discussion: For the CBMN results, a program was developed on Matlab platform to calculate the 95% confidence ellipse on the co-variance parameters α and β. These values were determined by fitting the linear quadratic dose response curve to the average number of radiation induced MNi per 1000 BN cells. The ellipse region around a coordinate (the average MN frequency) for both MCF-7 and MCF-10A cells at the plateau region was defined by the mean estimate of the α-value and the β-value that were plotted on the X-axis and Y-axis respectively. The ratio of the two parameters, α/β, is a measure of the impact of fractionation to determine the biological effective dose. In fractionated proton therapy, the MCF10A cells will repair less between two fractions compared to the MCF7 cells. This is not an indication of therapeutic gain from a fractioned treatment protocol. For this reason, the hypofractionated stereotactic treatment protocols that can be applied with protons could be to the befit of the breast cancer patient. The above argument is based only on the radiosensitivity of the two cell lines exposed in the plateau region. Further analysis of the 95% confidence ellipse of both cell lines also showed a clear increase of the alpha value toward the distal portion of the beam and indicates an increase in energy transfer in this region. The gradual increase in α and β parameters with depth for protons for both cells is of clinical importance, since it implicates a non-homogeneous dose within the targeted area and an unwanted high dose behind the targeted area. Distal energy modulation could be investigated especially with larger breast tumours. RBE was calculated as the ratio of the dose at the different positions to the dose at the entrance plateau position (reference) to obtain an equal level of biological effect. A statistically significant difference in radiosensitivity could be observed between malignant and non-malignant cells at all positions (p<0.05). The variation in RBE was between 0.99 to 1.99 and 0.92 to 1.6 for the MCF-7 and MCF10A cell respectively. Conclusions: There is a variation in RBE along the depth-dose profile of a clinical proton beam. In addition, there is difference in radiosensitivity between the cancerous cells and the normal breast cells. While this study highlights a variation in sensitivity between cells it could be used by the modelling community to further develop biologically motivated treatment planning for proton therapy.
10
Shani, Saeideh. "The implication of cell-derived microvesicles in retinal pigment epithelium degeneration". Thèse, 2018. http://hdl.handle.net/1866/22150.
Texto completoLibros sobre el tema "RPE in-Cell"
1
Bengtsson, Staffan. Studies on structures and properties of soluble cell-well polysaccharides in rye and barley. Uppsala: Swedish University of Agricultural Sciences, Dept. of Food Science, 1991.
Buscar texto completo
2
Monoclonal antibodies: Principles and practice : production and application of monoclonal antibodies in cell biology, biochemistry, and immunology. 2a ed. London: Academic Press, 1986.
Buscar texto completo
3
Rape in Holding Cell 6. Nazca Plains Corporation, The, 2011.
Buscar texto completo
4
Rape In Holding Cell 6. Nazca Plains Corporation, 2010.
Buscar texto completo
5
Sullivan, Kyle Michel. Rape in Holding Cell 6. KMSCB, 2014.
Buscar texto completo
6
McGough, Michael. A Field Guide to the Culture Wars. Greenwood Publishing Group, Inc, 2008. http://dx.doi.org/10.5040/9798400650796.
Texto completoResumen
Like any realignment in politics, the Democratic takeover of Congress in the 2006 midterm elections inspired a raft of instant analyses. One take on the results that is surely wrong is that the change in control of Congress and the spike in Democratic hopes for the 2008 presidential race mark an end to the culture wars that conventional wisdom blamed (or credited) for George W. Bush's re-election in 2004. This book sets the stage for a new consideration of the contemporary culture wars by examining their antecedents—from the Scopes trial to Prohibition to the controversy over the Supreme Court's desegregation and school-prayer rulings to loyalty-oath battles of the 1950s to the pre- Roe v. Wade campaign to liberalize abortion laws. Even during times of supposed conformism, Americans have been presented with competing claims about what sort of culture this is and how and to what extent government should reflect, and police, values. The author covers such topics as same-sex marriage, stem cell research, intelligent design, and other hot button issues that are debated not just between the religious and secular, but more and more among the ranks of the religious themselves, where a religious left has emerged to counter arguments from the religious right. Anyone interested in the intersection of religion and politics, in the rise of the so-called moral majority, and in the current state of affairs with regard to values and public life in America will gain a better understanding from reading this book.
7
Glausser, Wayne. Entanglement. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190864170.003.0001.
Texto completoResumen
This introductory chapter offers a brief definition of entanglement and contrasts it with four other versions of the relationship between religion and secularity. Unlike these other four models, in which religion and secularity sit apart from each other as separate domains, entanglement presents a contentious but oddly intimate relationship. Neither side simply wins by displacing the other. Two examples flesh out this definition of entangled religious and secular interests. The first example comes from the so-called War on Christmas; the second comes from controversies surrounding stem cell research. In both of these cases, religious and secular elements entangle and complicate each other, even as they engage in adversarial conversation. The introduction then examines recent scholarly re-evaluations of the term “secularity” and connects it with the concept of entanglement.
8
Tallacchini, Mariachiara. Medical Technologies and EU Law: The Evolution of Regulatory Approaches and Governance. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780198807216.003.0002.
Texto completoResumen
The regulatory evolution of medical technologies in the EU offers a unique perspective with regard to highlighting significant elements of both European science policy and the development of European institutions, especially with regard to the passage from their (primarily) economic to their political phases. Since the early 1990s, while establishing a market for biotechnology, the European Communities have been developing some policy-related visions of technoscience and its potential risks, while at the same time framing the concept of European citizenship through European values and rights. The emerging and re-emerging medical technology of xenotransplantation, namely the clinical use of cells, tissues, and organs between species, while having evolved from its primary focus on organs to so-called advanced therapies (cell therapy, gene therapy, and tissue-engineered products), also provided an opportunity to test and implement different science policy models in dealing with risks and uncertainties in the European knowledge-based and innovation-oriented society.
9
Izzedine, Hassan y Victor Gueutin. Drug-induced acute tubulointerstitial nephritis. Editado por Adrian Covic. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0084.
Texto completoResumen
Drug-induced acute tubulointerstitial nephritis (ATIN) is the most common aetiology of ATIN and a potentially correctable cause of acute kidney injury (AKI). An interval of 7–10 days typically exists between drug exposure and development of AKI, but this interval can be considerably shorter following re-challenge or markedly longer with certain drugs. It occurs in an idiosyncratic and non-dose-dependent manner. Antibiotics, NSAIDs, and proton pump inhibitors are the most frequently involved agents, but the list of drugs that can induce ATIN is continuously increasing. The mechanism of renal injury is postulated to involve cell-mediated immunity, supported by the observation that T cells are the predominant cell type comprising the interstitial infiltrate. A humoral response underlies rare cases of ATIN, in which a portion of a drug molecule (i.e. methicillin) may act as a hapten, bind to the tubular basement membrane (TBM), and elicit anti-TBM antibodies. The classic symptoms of fever, rash, and arthralgia may be absent in up to two-thirds of patients. Diagnostic studies, such as urine eosinophils and renal gallium-67 scanning provide only suggestive evidence. Renal biopsy remains the gold standard for diagnosis, but it may not be required in mild cases or when clinical improvement is rapid after removal of an offending medication. Pathologic findings include interstitial inflammation, oedema, and tubulitis. The time until removal of such agents and the severity of renal biopsy findings provide the best prognostic value for the return to baseline renal function. Poor prognostic indicators are the long duration of AKI (> 3 weeks), a patient’s advanced age, and the high degree of interstitial fibrosis. Early recognition and appropriate therapy are essential to the management of drug-induced ATIN, because patients can ultimately develop chronic kidney disease. The mainstay of therapy is timely discontinuation of the causative agent, whereas controversy persists about the role of steroids.
10
Snyder, Jeremy. Exploiting Hope. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780197501252.001.0001.
Texto completoResumen
One often hears stories of people in terrible and seemingly intractable situations who are preyed upon by individuals offering empty promises of help. Frequently these cases are condemned as “exploiting the hope” of another. These accusations are made in a range of contexts, including human smuggling, the beauty industry, and unproven medical interventions. This concept is meant to do heavy lifting in public discourse, identifying a specific form of unethical conduct. However, it is poorly understood what is meant to be wrong by the accusation of exploiting hope, the range of activities that can accurately be captured under this concept, and what should be done about it. Thus, it is an ethical concept that is ripe for extended analysis and discussion. This book offers a close study of the concept of exploiting hope. First, it examines this concept in the abstract, including a close look at how this term is used in the popular press and individual examinations of the concepts of exploitation and hope. This theory-based section culminates in the author’s own account of what it is to exploit hope and when and why doing so is morally problematic. The second section of the book examines how hope for improved health from unproven medical interventions can be exploited. This includes exploitation of hope in the context of participants in clinical trials, purchasing unproven stem cell interventions, right to try legislation, and crowdfunding for unproven interventions.
Capítulos de libros sobre el tema "RPE in-Cell"
1
Qin, Suofu. "Roles for AMP-Activated Protein Kinase in RPE Cell Function". En Retinal Degenerative Diseases, 745–51. Boston, MA: Springer US, 2011. http://dx.doi.org/10.1007/978-1-4614-0631-0_95.
Texto completo
2
Rashid, Alia, Shagun K. Bhatia, Karina I. Mazzitello, Micah A. Chrenek, Qing Zhang, Jeffrey H. Boatright, Hans E. Grossniklaus, Yi Jiang y John M. Nickerson. "RPE Cell and Sheet Properties in Normal and Diseased Eyes". En Retinal Degenerative Diseases, 757–63. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-17121-0_101.
Texto completo
3
Khristov, Vladimir, Arvydas Maminishkis, Juan Amaral, Aaron Rising, Kapil Bharti y Sheldon Miller. "Validation of iPS Cell-Derived RPE Tissue in Animal Models". En Retinal Degenerative Diseases, 633–40. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-75402-4_77.
Texto completo
4
Yamada, H., N. Ogata, C. Yamamoto, M. Miyashiro, M. Uyama y A. Del Monte. "Localization of bFGF in wound healing process of RPE cell in vitro". En Documenta Ophthalmologica Proceedings Series, 89–93. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5137-5_13.
Texto completo
5
Hazim, Roni, Mei Jiang, Julian Esteve-Rudd, Tanja Diemer, Vanda S. Lopes y David S. Williams. "Live-Cell Imaging of Phagosome Motility in Primary Mouse RPE Cells". En Retinal Degenerative Diseases, 751–55. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-17121-0_100.
Texto completo
6
Skottman, Heli. "RPE and Stem Cell Therapy". En Retinal Pigment Epithelium in Health and Disease, 249–63. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-28384-1_14.
Texto completo
7
Detrick, Barbara y John J. Hooks. "The RPE Cell and the Immune System". En Retinal Pigment Epithelium in Health and Disease, 101–14. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-28384-1_6.
Texto completo
8
Ben M’Barek, Karim, Walter Habeler, Florian Regent y Christelle Monville. "Developing Cell-Based Therapies for RPE-Associated Degenerative Eye Diseases". En Pluripotent Stem Cells in Eye Disease Therapy, 55–97. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-28471-8_3.
Texto completo
9
Hazim, Roni A. y David S. Williams. "Cell Culture Analysis of the Phagocytosis of Photoreceptor Outer Segments by Primary Mouse RPE Cells". En Methods in Molecular Biology, 63–71. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-7720-8_4.
Texto completo
10
Kuhns, Stefanie, Alice Dupont Juhl, Zeinab Anvarian, Daniel Wüstner, Lotte B. Pedersen y Jens S. Andersen. "Endogenous Tagging of Ciliary Genes in Human RPE1 Cells for Live-Cell Imaging". En Methods in Molecular Biology, 147–66. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-3507-0_9.
Texto completoActas de conferencias sobre el tema "RPE in-Cell"
1
Delori, François C. "Fluorophotometer for Noninvasive Measurement of RPE Lipofuscin". En Noninvasive Assessment of the Visual System. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/navs.1992.tuc3.
Texto completoResumen
Lipofuscin is a fluorescent pigment that accumulates throughout life preferentially in the macular RPE. At old age, lipofuscin is the major constituent of the cell as it occupies most of the free cytoplasmic [1]. It has been hypothesized that cell congestion by lipofuscin affects the normal metabolic activity of the RPE [1-3], and that this process plays a role in the pathogenesis of age-related macular degeneration (AMD). Massively engorged RPE cells are found adjacent to areas where the RPE is absent secondary to atrophy in AMD [3]. Although the evidence for lipofuscin involvement in AMD is circumstantial, the possibility of quantifying lipofuscin concentration in old subjects and in patients with AMD offers the potential of a meaningful clinical evaluation of the role of lipofuscin in the development of degenerative diseases such as AMD.
2
Kelly, Michael W. y Charles P. Lin. "Microcavitation and cell injury in RPE cells following short-pulsed laser irradiation". En BiOS '97, Part of Photonics West, editado por Steven L. Jacques. SPIE, 1997. http://dx.doi.org/10.1117/12.275473.
Texto completo
3
Glickman, Randolph D., Meena Vendal, Mary Ann Gonzalez y Neeru Kumar. "Intracellular photochemical reactions in the RPE cell exhibit a wavelength dependence that resembles the action spectrum of melanin". En BiOS '99 International Biomedical Optics Symposium, editado por Steven L. Jacques, Gerhard J. Mueller, Andre Roggan y David H. Sliney. SPIE, 1999. http://dx.doi.org/10.1117/12.349992.
Texto completo
4
Brinkmann, Ralf, Jan Roegener, Charles P. Lin, Johann Roider, Reginald Birngruber y Gereon Huettmann. "Selective RPE photodestruction: mechanism of cell damage by pulsed-laser irradiance in the ns to μm time regime". En BiOS '99 International Biomedical Optics Symposium, editado por Steven L. Jacques, Gerhard J. Mueller, Andre Roggan y David H. Sliney. SPIE, 1999. http://dx.doi.org/10.1117/12.350041.
Texto completo
5
Patel, Gaurav, Hitesh Tekchandani y Shrish Verma. "Intermediate Generation Selection Attention and Multi-scale Feature Aggregation for segmentation of cell regions in RPE implant absorbance images". En 2020 IEEE 17th India Council International Conference (INDICON). IEEE, 2020. http://dx.doi.org/10.1109/indicon49873.2020.9342342.
Texto completo
6
Schüle, Georg, Elke Joachimmeyer, Carsten Framme, Johann Roider, Reginald Birngruber y Ralf Brinkmann. "Optoacoustic detection of selective RPE cell damage during µs-laser irradiation". En European Conference on Biomedical Optics. Washington, D.C.: Optica Publishing Group, 2001. http://dx.doi.org/10.1364/ecbo.2001.4433_92.
Texto completoResumen
Objective: The selective damage of the retinal pigment epithelium (RPE) with repetitive µs laser pulses is a new technique for the treatment of several retinal diseases. RPE can selectively be damaged by simultaneously sparing off the adjacent photoreceptor tissue. Objective of this study is to investigate whether optoacoustic (OA) transients occurring during irradiation might be used to control the invisible treatment effect. Setup: A train of frequency doubled Nd:YLF laser pulses (527 nm, 1.7µs pulse length, 500Hz rep. rate) were applied via a laser slit lamp on porcine RPE samples. The acoustic transients were recorded with a broadband transducer. Results: At low radiant exposures (< 100 mJ/cm2) we found a bipolar pressure transient due to thermoelastic expansion of the RPE. The pressure waves from the individual pulses of one pulse train show nearly identical transients. The transients differ slightly from different sites on the sample. At higher radiant exposures (> 150 mJ/cm2), the OA transients differ from pulse to pulse within a pulse train, which can be attributed to microbubble formation around the strong absorbing melanosomes inside the RPE cells. FFT spectra of the OA transients show slight differences in the frequency spectrum with the different radiant exposures.
7
Zhang, Xiongjun, Jun Zhang, Dengsheng Wu, Jiangang Zheng, Mingzhong Li, Kuixing Zheng, Jingqin Su y Feng Jing. "Progress of rep-rate plasma Pockels cell technology in RCLF". En SPIE LASE, editado por Abdul A. S. Awwal, A. Mike Dunne, Hiroshi Azechi y Brian E. Kruschwitz. SPIE, 2011. http://dx.doi.org/10.1117/12.876549.
Texto completo
8
Ruby, Douglas S., Saleem Zaidi, S. Narayanan, Satoshi Yamanaka y Ruben Balanga. "RIE-Texturing of Industrial Multicrystalline Silicon Solar Cells". En ASME 2003 International Solar Energy Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/isec2003-44003.
Texto completoResumen
We developed a maskless plasma texturing technique for multicrystalline Si (mc-Si) cells using Reactive Ion Etching (RIE) that results in higher cell performance than that of standard untextured cells. Elimination of plasma damage has been achieved while keeping front reflectance to low levels. Internal quantum efficiencies higher than those on planar and wet-textured cells have been obtained, boosting cell currents and efficiencies by up to 6% on tricrystalline Si cells.
9
Zhao, Yu, Ignas Niemegeers y Sonia Heemstra de Groot. "Power Allocation in mmWave Cell-F ree Massive MIMO with User Mobility Using Deep Learning". En 2020 IEEE 20th International Conference on Communication Technology (ICCT). IEEE, 2020. http://dx.doi.org/10.1109/icct50939.2020.9295936.
Texto completo
10
Chitakudige, Ramachandra, Sarat Kumar Dash y A. M. Khan. "Deprocessing Methodologies for Detection of IBC and Cell-to-Cell Shorts in Submicron DRAM". En ISTFA 2012. ASM International, 2012. http://dx.doi.org/10.31399/asm.cp.istfa2012p0383.
Texto completoResumen
Abstract Detection of both Insufficient Buried Contact (IBC) and cell-to-cell short defects is quite a challenging task for failure analysis in submicron Dynamic Random Access Memory (DRAM) devices. A combination of a well-controlled wet etch and high selectivity poly silicon etch is a key requirement in the deprocessing of DRAM for detection of these types of failures. High selectivity poly silicon etch methods have been reported using complicated system such as ECR (Electron Cyclotron Resonance) Plasma system. The fact that these systems use hazardous gases like Cl2, HBr, and SF6 motivates the search for safer alternative deprocessing chemistries. The present work describes high selectivity poly silicon etch using simple Reactive Ion Etch (RIE) plasma system using less hazardous gases such as CF4, O2 etc. A combination of controlled wet etch and high selectivity poly silicon etch have been used to detect both IBC and cell-to-cell shorts in submicron DRAMs.
Informes sobre el tema "RPE in-Cell"
1
Carpita, Nicholas C., Ruth Ben-Arie y Amnon Lers. Pectin Cross-Linking Dynamics and Wall Softening during Fruit Ripening. United States Department of Agriculture, julio de 2002. http://dx.doi.org/10.32747/2002.7585197.bard.
Texto completoResumen
Our study was designed to elucidate the chemical determinants of pectin cross-linking in developing fruits of apple and peach and to evaluate the role of breakage cross-linkages in swelling, softening, and cell separation during the ripening. Peaches cell walls soften and swell considerably during the ripening, whereas apples fruit cells maintain wall firmness but cells separate during late stages of ripening. We used a "double-reduction" technique to show that levels of non-methyl esters of polyuronic acid molecules were constant during the development and ripening and decreased only in overripe fruit. In peach, methyl and non-methyl esters increased during the development and decreased markedly during the ripening. Non-methyl ester linkages in both fruit decreased accompanied fruit softening. The identity of the second component of the linkage and its definitive role in the fruit softening remain elusive. In preliminary examination of isolated apples cell walls, we found that phenolic compounds accumulate early in wall development but decrease markedly during ripening. Quantitative texture analysis was used to correlate with changes to wall chemistry from the fresh-picked ripe stage to the stage during storage when the cell separation occurs. Cell wall composition is similar in all cultivars, with arabinose as the principal neutral sugar. Extensive de-branching of these highly branched arabinans pre-stages softening and cell-cell separation during over-ripening of apple. The longer 5-arabinans remain attached to the major pectic polymer rhamnogalacturonan I (RG I) backbone. The degree of RG I branching, as judged from the ratios of 2-Rha:2,4-Rha, also decreases, specially after an extensive arabinan de-branching. Loss of the 4-Rham linkages correlated strongly with the softening of the fruit. Loss of the monomer or polymer linked to the RG I produce directly or indirectly the softening of the fruit. This result will help to understand the fruit softening and to have better control of the textural changes in fruit during the ripening and especially during the storage. 'Wooliness', an undesirable mealy texture that is induced during chilling of some peach cultivars, greatly reduces the fruit storage possibilities. In order to examine the hypothesis that the basis for this disorder is related to abnormality in the cell wall softening process we have carried out a comparative analysis using the resistant cultivar, Sunsnow, and a sensitive one, Hermosa. We investigated the activity of several pectin- and glycan-modifying enzymes and the expression of their genes during ripening, chilling, and subsequent shelf-life. The changes in carbohydrate status and in methyl vs. non-methyl uronate ester levels in the walls of these cultivars were examined as well to provide a basis for comparison of the relevant gene expression that may impact appearance of the wooly character. The activities of the specific polygalacturonase (PGase) and a CMC-cellulase activities are significantly elevated in walls of peaches that have become wooly. Cellulase activities correlated well with increased level of the transcript, but differential expression of PGase did not correspond with the observed pattern of mRNA accumulation. When expression of ethylene biosynthesis related genes was followed no significant differences in ACC synthase gene expression was observed in the wooly fruit while the normal activation of the ACC oxidase was partially repressed in the Hermosa wooly fruits. Normal ripening-related loss of the uronic acid-rich polymers was stalled in the wooly Hermosa inconsistent with the observed elevation in a specific PGase activity but consistent with PG gene expression. In general, analysis of the level of total esterification, degree of methyl esterification and level of non-methyl esters did not reveal any major alterations between the different fruit varieties or between normal and abnormal ripening. Some decrease in the level of uronic acids methyl esterification was observed for both Hermosa and Sunsnow undergoing ripening following storage at low temperature but not in fruits ripening after harvest. Our results support a role for imbalanced cell wall degradation as a basis for the chilling disorder. While these results do not support a role for the imbalance between PG and pectin methyl esterase (PME) activities as the basis for the disorder they suggest a possible role for imbalance between cellulose and other cell wall polymer degradation during the softening process.
2
Manulis, Shulamit, Christine D. Smart, Isaac Barash, Guido Sessa y Harvey C. Hoch. Molecular Interactions of Clavibacter michiganensis subsp. michiganensis with Tomato. United States Department of Agriculture, enero de 2011. http://dx.doi.org/10.32747/2011.7697113.bard.
Texto completoResumen
Clavibacter michiganensis subsp. michiganensis (Cmm), the causal agent of bacterial wilt and canker of tomato, is the most destructive bacterial disease of tomato causing substantial economic losses in Israel, the U.S.A. and worldwide. The molecular strategies that allow Cmm, a Gram-positive bacterium, to develop a successful infection in tomato plants are largely unknown. The goal of the project was to elucidate the molecular interactions between Cmmand tomato. The first objective was to analyze gene expression profiles of susceptible tomato plants infected with pathogenic and endophytic Cmmstrains. Microarray analysis identified 122 genes that were differentially expressed during early stages of infection. Cmm activated typical basal defense responses in the host including induction of defense-related genes, production of scavenging of free oxygen radicals, enhanced protein turnover and hormone synthesis. Proteomic investigation of the Cmm-tomato interaction was performed with Multi-Dimensional Protein Identification Technology (MudPIT) and mass spectroscopy. A wide range of enzymes secreted by Cmm382, including cell-wall degrading enzymes and a large group of serine proteases from different families were identified in the xylem sap of infected tomato. Based on proteomic results, the expression pattern of selected bacterial virulence genes and plant defense genes were examined by qRT-PCR. Expression of the plasmid-borne cellulase (celA), serine protease (pat-1) and serine proteases residing on the chp/tomA pathogenicity island (chpCandppaA), were significantly induced within 96 hr after inoculation. Transcription of chromosomal genes involved in cell wall degradation (i.e., pelA1, celB, xysA and xysB) was also induced in early infection stages. The second objective was to identify by VIGS technology host genes affecting Cmm multiplication and appearance of disease symptoms in plant. VIGS screening showed that out of 160 tomato genes, which could be involved in defense-related signaling, suppression of 14 genes led to increase host susceptibility. Noteworthy are the genes Snakin-2 (inhibitor of Cmm growth) and extensin-like protein (ELP) involved in cell wall fortification. To further test the significance of Snakin -2 and ELP in resistance towards Cmm, transgenic tomato plants over-expressing the two genes were generated. These plants showed partial resistance to Cmm resulting in a significant delay of the wilt symptoms and reduction in size of canker lesion compared to control. Furthermore, colonization of the transgenic plants was significantly lower. The third objective was to assess the involvement of ethylene (ET), jasmonate (JA) and salicylic acid (SA) in Cmm infection. Microarray and proteomic studies showed the induction of enzymes involved in ET and JA biosynthesis. Cmm promoted ET production 8 days after inoculation and SIACO, a key enzyme of ET biosynthesis, was upregulated. Inoculation of the tomato mutants Never ripe (Nr) impaired in ET perception and transgenic plants with reduced ET synthesis significantly delayed wilt symptoms as compared to the wild-type plants. The retarded wilting in Nr plants was shown to be a specific effect of ET insensitivity and was not due to altered expression of defense related genes, reduced bacterial population or decrease in ethylene biosynthesis . In contrast, infection of various tomato mutants impaired in JA biosynthesis (e.g., def1, acx1) and JA insensitive mutant (jai1) yielded unequivocal results. The fourth objective was to determine the role of cell wall degrading enzymes produced by Cmm in xylem colonization and symptoms development. A significance increase (2 to 7 fold) in expression of cellulases (CelA, CelB), pectate lyases (PelA1, PelA2), polygalacturonase and xylanases (XylA, XylB) was detected by qRT-PCR and by proteomic analysis of the xylem sap. However, with the exception of CelA, whose inactivation led to reduced wilt symptoms, inactivation of any of the other cell wall degrading enzymes did not lead to reduced virulence. Results achieved emphasized the complexity involved in Cmm-tomato interactions. Nevertheless they provide the basis for additional research which will unravel the mechanism of Cmm pathogenicity and formulating disease control measures.
3
Prusky, Dov, Noel T. Keen y Stanley Freeman. Elicitation of Preformed Antifungal Compounds by Non-Pathogenic Fungus Mutants and their Use for the Prevention of Postharvest Decay in Avocado Fruits. United States Department of Agriculture, enero de 1996. http://dx.doi.org/10.32747/1996.7570573.bard.
Texto completoResumen
C. gloeosporioides attacks unripe avocado fruits in the orchard. Germinated spores produce appressoria that germinate and breach the cuticle, but the resultant subcuticular hyphae become quiescent and do not develop further until fruit is harvested and ripens. Resistance of unripe avocado to attach by C. gloeosporioides is correlated with the presence of fungitoxic concentrations of the preformed antifungal compound, 1-acetoxy-2-hydroxy-4-oxoheneicosa-12, 15 diene in the pericarp of unripe fruits. The objective of this proposal was to study the signal transduction process by which elicitors induce resistance in avocado. It was found that abiotic elicitors, infection of avocado fruit with C. gloeosporioides or treatment of avocado cell suspension with cell-wall elicitor induced a significant production of reactive oxygen species (ROS). Ripe and unripe fruit tissue differ with regard to the ROS production. The unripe, resistant fruit are physiologically able to react and to produce high levels of ROS and increased activity of H+ATPase that can enhance the phenylpropanoid pathway ad regulate the levels of the antifungal compound-diene, inhibit fungal development, resulting in its quiescence. Interestingly, it was also found that growth regulators like cytokinin could do activation of the mechanism of resistance. Postharvest treatments of cytokinins strongly activated the phenylpropanoid pathway and induce resistance. We have developed non-pathogenic strains of C. gloeosporioides by Random Enzyme Mediated Integration and selected a hygromycin resistance, non-pathogenic strain Cg-142 out of 3500 transformants. This non-pathogenic isolate activates H+ATPase and induces resistance against Colletotrichum attack. As a basis for studying the importance of PL in pathogenicity, we have carried out heterologous expression of pel from C. gloeosporioides in the non-pathogenic C. magna and determine the significant increase in pathogenicity of the non-pathogenic strain. Based on these results we can state that pectate lyase is an important pathogenicity factor of C. gloeosporioides and found that fungal pathogenicity is affected not by pel but by PL secretion. Our results suggest that PH regulates the secretion of pectate lyase, and support its importance as a pathogenicity factor during the attack of avocado fruit by C. gloeosporioides . This implicates that if these findings are of universal importance in fungi, control of disease development could be done by regulation of secretion of pathogenicity factors.
4
Friedmann, Michael, Charles J. Arntzen y Hugh S. Mason. Expression of ETEC Enterotoxin in Tomato Fruit and Development of a Prototype Transgenic Tomato for Dissemination as an Oral Vaccine in Developing Countries. United States Department of Agriculture, marzo de 2003. http://dx.doi.org/10.32747/2003.7585203.bard.
Texto completoResumen
The broad objective of the project was to develop a feasible approach to combat diarrheal disease caused by ETEC through the development of a low-cost oral immunogen in tomato fruit, expressed in the context of a prototype tomato that would answer the shortcomings of plant oral vaccines, especially in terms of produce handling and control of gene escape. Specifically, the goals for Boyce Thompson Institute (BTI) on this project were to develop transgenic tomato lines that express the enterotoxigenic E. coli (ETEC) heat-labile enterotoxin (LT) subunits A and/or B for use in oral edible vaccines, and to optimize expression and assembly of these antigens in tomato fruits.LT-B is a useful vaccine antigen against ETEC disease, since antibodies against LT-B can prevent binding and delivery of the holotoxinLT. Mutant forms of the toxic LT-A subunit that have reduced toxicity can be co-expressed and assembled with LT-Bpentamers to form mutant LT (mLT) complexes that could be used as mucosaladjuvants for other oral vaccines. Work on the project is continuing at Arizona State University, after Dr. Mason moved there in August 2002. A number of approaches were taken to ensure the expression of both subunits and bring about their assembly inside the transgenic fruits. Initially, expression was driven by the fruit-specific E-8 promoter for LT-B and the constitutive CaMV 35S promoter for LT-A(K63). While LT-B accumulated up to 7 µg per gram ripe fruit, assembled LT-K63 was only 1 µg per gram. Since promoter activities for the two genes likely differed in cell type and developmental stage specificity, the ratios of A and B subunits was not optimal for efficient assembly in all cells. In order to maximize the chance of assembly of mLT in fruit, we focused on constructs in which both genes are driven by the same promoter. These included co-expression plasmids using the 35S promoter for both, while switching to attenuated mLTs (LT-R72 and LT-G192) that have shown greater potential for oral adjuvanticity than the initial LT-K63, and thus are better candidates for a plant-derived adjuvant. Other, more novel approaches were then attempted, including several new vectors using the tomato fruit-specific E8 promoter driving expression of both LT-B and mutant LT-A, as well as a dicistronic construct for co-expression of both LT-B and mutant LT-A genes from a single promoter, and a geminivirusreplicon construct. We describe in the Appendix the results obtained in transgenic tomato lines transformed with these constructs. Overall, each contributed to enhanced expression levels, but the assembly itself of the holotoxin to high levels was not observed in the fruit tissues. The Israeli lab’s specific objective was to develop transgenic tomato lines expressing the LTholotoxin antigen bearing attributes to prevent gene escape (male sterility and orange fruit color) and to improve the dissemination of the oral vaccine (long shelf-life tomato cherry fruit or tomato processing background). Breeding lines bearing a number of attributes to prevent gene escape were developed by combining material and backcrossing either to a tomato cherry background, or two different processing backgrounds. Concomitantly, (these lines can be utilized for the creation of any future oral vaccine or other therapeutic-expressing tomato, either by crosses or transformation), the lines were crossed to the holotoxin-expressing tomatoes received from the United States, and this transgenic material was also incorporated into the backcrossing programs. To date, we have finalized the preparation of the cherry tomato material, both non-transgenic (bearing all the desired attributes), and transgenic, expressing the holotoxin. The level of expression of LT-B in the cherry fruits was comparable to the original transgenic tomatoes. Since it was not higher, this would necessitate the consumption of more fruits to reach a desired dose. A final backcross has been made for both the non-transgenic and the transgenic material in the processing lines. Auxin sprays resulted in high percentages of fruit set, but the processing genotypes gave many puffed fruits.
5
Sengupta-Gopalan, Champa, Shmuel Galili y Rachel Amir. Improving Methionine Content in Transgenic Forage Legumes. United States Department of Agriculture, febrero de 2001. http://dx.doi.org/10.32747/2001.7580671.bard.
Texto completoResumen
Leguminous forage crops are high in proteins but deficient in S- amino acids. It has been shown that both wool quality and milk production can be limited by the post-ruminal supply of sulfur-containing amino acids. Efforts to use conventional plant breeding and cell selection techniques to increase the S-amino acid content of alfalfa have met with little success. With the objective to increase the S-amino acid content of forage legumes, the goal of this project was to co- express the methionine rich zein genes from corn along with a gene for a key enzyme in methionine biosynthesis, aspartate kinase(AK). The zeins are seed storage proteins from corn and are groupec into four distinct classes based on their amino acid sequence homologies. The b-zein (15kd) and the 6zein (10kD and 18kD) have proportionately high levels of methionine (10%, 22% and 28%, respectively). Initial studies from our lab had shown that while the 15kD zein accumulated to high levels in vegetative tissues of transgenic tobacco the l0kD zein did not. However, co-expression of the 10kD zein with the 15kD zein genes in tobacco showed stabilization of the 10kD zein and the co-localization of the 10kD and 15kD zein proteins in unique ER derived protein bodies. AK is the key enzyme for producing carbon skeletons for all amino acids of the aspartate family including methionine. It is, however, regulated by end-product feedback inhibition. The specific objectives of this proposal were: i. to co-express the 15kD zein with the 10/18kD zein genes in alfalfa in order to enhance the level of accumulation of the 10/18kD zein; ii. to increase methionine pools by expressing a feedback insensitive AK gene in transformants co-expressing the 15kD and 10/18kD zein genes. The Israeli partners were successful in expressing the AK gene in alfalfa which resulted in an increase in free and bound threonine but not in methionine (Galili et al., 2000). Since our target was to increase methionine pools, we changed our second objective to replace the AK gene with the gene for cystathionine gamma synthase (CGS) in the co-expression studies. The first methionine specific reaction is catalyzed by CGS. An additional objective was to develop a transformation system for Berseem clover, and to introduce the appropriate gene constructs into it with the goal of improving their methionine content. Genes for the 15kD zein along with the genes for either the 10kD or 18kD zein have been introduced into the same alfalfa plant both by sexual crosses and by re-transformation. Analysis of these zein co-expressors have shown that both the IOkD and 18kD zein levels go up 5 to 10 fold when co-expressed with the 15kD zein (Bagga et al., MS in preparation). Incubation of the leaves of transgenic alfalfa co-expressing the 15kD and 10kD zein genes, in the rumen of cows have shown that the zein proteins are stable in the rumen. To increase the level of zein accumulation in transgenic alfalfa different promoters have been used to drive the zein genes in alfalfa and we have concluded that the CaMV 35S promoter is superior to the other strong leaf -specific promoters. By feeding callus tissue of alfalfa plants co-expressing the 15kD and 10kD zein genes with methionine and its precursors, we have shown that the zein levels could be significantly enhanced by increasing the methionine pools. We have now introduced the CGS gene (from Arabidopsis; kindly provided to us by Dr. Leustek), into the 15kD zein transformants and experiments are in progress to check if the expression of the CGS gene indeed increases the level of zein accumulation in alfalfa. We were not successful in developing a transformation protocol for Berseem clover.
6
Fahima, Tzion y Jorge Dubcovsky. Map-based cloning of the novel stripe rust resistance gene YrG303 and its use to engineer 1B chromosome with multiple beneficial traits. United States Department of Agriculture, enero de 2013. http://dx.doi.org/10.32747/2013.7598147.bard.
Texto completoResumen
Research problem: Bread wheat (Triticumaestivum) provides approximately 20% of the calories and proteins consumed by humankind. As the world population continues to increase, it is necessary to improve wheat yields, increase grain quality, and minimize the losses produced by biotic and abiotic stresses. Stripe rust, caused by Pucciniastriiformisf. sp. tritici(Pst), is one of the most destructive diseases of wheat. The new pathogen races are more virulent and aggressive than previous ones and have produced large economic losses. A rich source for stripe-rust resistance genes (Yr) was found in wild emmer wheat populations from Israel. Original Project goals: Our long term goal is to identify, map, clone, characterize and deploy in breeding, novel wild emmer Yr genes, and combine them with multiple beneficial traits. The current study was aiming to map and clone YrG303 and Yr15, located on chromosome 1BS and combine them with drought resistance and grain quality genes. Positional cloning of YrG303/Yr15: Fine mapping of these genes revealed that YrG303 is actually allelic to Yr15. Fine genetic mapping using large segregating populations resulted in reduction of the genetic interval spanning Yr15 to less than 0.1 cM. Physical mapping of the YrG303/Yr15 locus was based on the complete chromosome 1BS physical map of wheat constructed by our group. Screening of 1BS BAC library with Yr15 markers revealed a long BAC scaffold covering the target region. The screening of T. dicoccoidesaccession-specific BAC library with Yr15 markers resulted in direct landing on the target site. Sequencing of T. dicoccoidesBAC clones that cover the YrG303/Yr15 locus revealed a single candidate gene (CG) with conserved domains that may indicate a role in disease resistance response. Validation of the CG was carried out using EMS mutagenesis (loss-of- function approach). Sequencing of the CG in susceptible yr15/yrG303 plants revealed three independent mutants that harbour non-functional yr15/yrG303 alleles within the CG conserved domains, and therefore validated its function as a Pstresistance gene. Evaluation of marker-assisted-selection (MAS) for Yr15. Introgressions of Yr15 into cultivated wheat are widely used now. Recently, we have shown that DNA markers linked to Yr15 can be used as efficient tools for introgression of Yr15 into cultivated wheat via MAS. The developed markers were consistent and polymorphic in all 34 tested introgressions and are the most recommended markers for the introgression of Yr15. These markers will facilitate simultaneous selection for multiple Yr genes and help to avoid escapees during the selection process. Engineering of improved chromosome 1BS that harbors multiple beneficial traits. We have implemented the knowledge and genetic resources accumulated in this project for the engineering of 1B "super-chromosome" that harbors multiple beneficial traits. We completed the generation of a chromosome including the rye 1RS distal segment associated with improved drought tolerance with the Yr gene, Yr15, and the strong gluten allele 7Bx-over-expressor (7Bxᴼᴱ). We have completed the introgression of this improved chromosome into our recently released variety Patwin-515HP and our rain fed variety Kern, as well as to our top breeding lines UC1767 and UC1745. Elucidating the mechanism of resistance exhibited by Yr36 (WKS1). The WHEAT KINASE START1 (WKS1) resistance gene (Yr36) confers partial resistance to Pst. We have shown that wheat plants transformed with WKS1 transcript are resistant to Pst. WKS1 is targeted to the chloroplast where it phosphorylates the thylakoid-associatedascorbateperoxidase (tAPX) and reduces its ability to detoxify peroxides. Based on these results, we propose that the phosphorylation of tAPX by WKS1 reduces the ability of the cells to detoxify ROS and contributes to cell death. Distribution and diversity of WKS in wild emmer populations. We have shown that WKS1 is present only in the southern distribution range of wild emmer in the Fertile Crescent. Sequence analysis revealed a high level of WKS1 conservation among wild emmer populations, in contrast to the high level of diversity observed in NB-LRR genes. This phenomenon shed some light on the evolution of genes that confer partial resistance to Pst. Three new WKS1 haplotypes displayed a resistance response, suggesting that they can be useful to improve wheat resistance to Pst. In summary, we have improved our understanding of cereals’ resistance mechanisms to rusts and we have used that knowledge to develop improved wheat varieties.
7
Hovav, Ran, Peggy Ozias-Akins y Scott A. Jackson. The genetics of pod-filling in peanut under water-limiting conditions. United States Department of Agriculture, enero de 2012. http://dx.doi.org/10.32747/2012.7597923.bard.
Texto completoResumen
Pod-filling, an important yield-determining stage is strongly influenced by water stress. This is particularly true for peanut (Arachishypogaea), wherein pods are developed underground and are directly affected by the water condition. Pod-filling in peanut has a significant genetic component as well, since genotypes are considerably varied in their pod-fill (PF) and seed-fill (SF) potential. The goals of this research were to: Examine the effects of genotype, irrigation, and genotype X irrigation on PF and SF. Detect global changes in mRNA and metabolites levels that accompany PF and SF. Explore the response of the duplicate peanut pod transcriptome to drought stress. Study how entire duplicated PF regulatory processes are networked within a polyploid organism. Discover locus-specific SNP markers and map pod quality traits under different environments. The research included genotypes and segregating populations from Israel and US that are varied in PF, SF and their tolerance to water deficit. Initially, an extensive field trial was conducted to investigate the effects of genotype, irrigation, and genotype X irrigation on PF and SF. Significant irrigation and genotypic effect was observed for the two main PF related traits, "seed ratio" and "dead-end ratio", demonstrating that reduction in irrigation directly influences the developing pods as a result of low water potential. Although the Irrigation × Genotype interaction was not statistically significant, one genotype (line 53) was found to be more sensitive to low irrigation treatments. Two RNAseq studies were simultaneously conducted in IL and the USA to characterize expression changes that accompany shell ("source") and seed ("sink") biogenesis in peanut. Both studies showed that SF and PF processes are very dynamic and undergo very rapid change in the accumulation of RNA, nutrients, and oil. Some genotypes differ in transcript accumulation rates, which can explain their difference in SF and PF potential; like cvHanoch that was found to be more enriched than line 53 in processes involving the generation of metabolites and energy at the beginning of seed development. Interestingly, an opposite situation was found in pericarp development, wherein rapid cell wall maturation processes were up-regulated in line 53. Although no significant effect was found for the irrigation level on seed transcriptome in general, and particularly on subgenomic assignment (that was found almost comparable to a 1:1 for A- and B- subgenomes), more specific homoeologous expression changes associated with particular biosynthesis pathways were found. For example, some significant A- and B- biases were observed in particular parts of the oil related gene expression network and several candidate genes with potential influence on oil content and SF were further examined. Substation achievement of the current program was the development and application of new SNP detection and mapping methods for peanut. Two major efforts on this direction were performed. In IL, a GBS approach was developed to map pod quality traits on Hanoch X 53 F2/F3 generations. Although the GBS approach was found to be less effective for our genetic system, it still succeeded to find significant mapping locations for several traits like testa color (linkage A10), number of seeds/pods (A5) and pod wart resistance (B7). In the USA, a SNP array was developed and applied for peanut, which is based on whole genome re-sequencing of 20 genotypes. This chip was used to map pod quality related traits in a Tifrunner x NC3033 RIL population. It was phenotyped for three years, including a new x-ray method to phenotype seed-fill and seed density. The total map size was 1229.7 cM with 1320 markers assigned. Based on this linkage map, 21 QTLs were identified for the traits 16/64 weight, kernel percentage, seed and pod weight, double pod and pod area. Collectively, this research serves as the first fundamental effort in peanut for understanding the PF and SF components, as a whole, and as influenced by the irrigation level. Results of the proposed study will also generate information and materials that will benefit peanut breeding by facilitating selection for reduced linkage drag during introgression of disease resistance traits into elite cultivars. BARD Report - Project4540 Page 2 of 10