RESUMEN
The lineage and developmental trajectory of a cell are key determinants of cellular identity. In the vascular system, endothelial cells (ECs) of blood and lymphatic vessels differentiate and specialize to cater to the unique physiological demands of each organ1,2. Although lymphatic vessels were shown to derive from multiple cellular origins, lymphatic ECs (LECs) are not known to generate other cell types3,4. Here we use recurrent imaging and lineage-tracing of ECs in zebrafish anal fins, from early development to adulthood, to uncover a mechanism of specialized blood vessel formation through the transdifferentiation of LECs. Moreover, we demonstrate that deriving anal-fin vessels from lymphatic versus blood ECs results in functional differences in the adult organism, uncovering a link between cell ontogeny and functionality. We further use single-cell RNA-sequencing analysis to characterize the different cellular populations and transition states involved in the transdifferentiation process. Finally, we show that, similar to normal development, the vasculature is rederived from lymphatics during anal-fin regeneration, demonstrating that LECs in adult fish retain both potency and plasticity for generating blood ECs. Overall, our research highlights an innate mechanism of blood vessel formation through LEC transdifferentiation, and provides in vivo evidence for a link between cell ontogeny and functionality in ECs.
Asunto(s)
Vasos Sanguíneos , Transdiferenciación Celular , Vasos Linfáticos , Aletas de Animales/citología , Animales , Vasos Sanguíneos/citología , Linaje de la Célula , Células Endoteliales/citología , Vasos Linfáticos/citología , Pez CebraRESUMEN
Identification of signaling events that contribute to innate spinal cord regeneration in zebrafish can uncover new targets for modulating injury responses of the mammalian central nervous system. Using a chemical screen, we identify JNK signaling as a necessary regulator of glial cell cycling and tissue bridging during spinal cord regeneration in larval zebrafish. With a kinase translocation reporter, we visualize and quantify JNK signaling dynamics at single-cell resolution in glial cell populations in developing larvae and during injury-induced regeneration. Glial JNK signaling is patterned in time and space during development and regeneration, decreasing globally as the tissue matures and increasing in the rostral cord stump upon transection injury. Thus, dynamic and regional regulation of JNK signaling help to direct glial cell behaviors during innate spinal cord regeneration.
Asunto(s)
Traumatismos de la Médula Espinal , Regeneración de la Medula Espinal , Animales , Larva , Mamíferos , Regeneración Nerviosa/fisiología , Neuroglía/fisiología , Médula Espinal , Pez Cebra/fisiología , Proteínas Quinasas JNK Activadas por MitógenosRESUMEN
In this study, ZIF-8 nanoparticles were synthesized using a simple method at room temperature. The ZIF-8 nanoparticles were then characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET (Brunauer-Emmett-Teller) specific surface area, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and zeta potential. Subsequent batch adsorption experiments evaluated the adsorption performance of ZIF-8 on tetracycline, examining key pa-rameters like reaction time, pH, temperature, and adsorbent dosage. The results revealed a removal rate for TC of up to 90.59%. The adsorption data aligned with the Sips model, showcasing a maximum adsorption capacity of 359.61 mg/g at 303K. Further, the adsorption kinetics adhered to the pseudo-second-order kinetic model with an equilibrium adsorption capacity of 90 mg/g at 303K. The considerable specific surface area of ZIF-8, standing at 1674.169 m2/g, likely enhances the adsorption efficacy. Analysis using XRD and FTIR confirmed the adsorption of TC on the ma-terial's surface. Overall, the predominant driving forces behind the adsorption process were identified as electrostatic interactions and π-π stacking interactions.
Asunto(s)
Contaminantes Químicos del Agua , Adsorción , Contaminantes Químicos del Agua/análisis , Tetraciclina , Antibacterianos/química , Termodinámica , Agua , Cinética , Espectroscopía Infrarroja por Transformada de Fourier , Concentración de Iones de HidrógenoRESUMEN
BACKGROUND: Ethylene plays a vital role in the ripening process of kiwifruit. A terrific amount of transcription factors (TFs) have been shown to regulate ethylene synthesis in various fruits. RESULTS: In this research, two new NAC TFs, named AcNAC3 and AcNAC4, were isolated from kiwifruit, which belonged to NAM subfamily. Bioinformatics analysis showed that both AcNAC3 and AcNAC4 were hydrophilic proteins with similar three-dimensional structures. The expression levels of AcNAC3, AcNAC4 and AcACO1 increased during kiwifruit ripening, as well as were induced by ethylene and repressed by 1-methylcyclopropene (1-MCP). Correlation analysis exhibited that ethylene production was positively correlated with the expression levels of AcNAC3, AcNAC4 and AcACO1. Moreover, both AcNAC3 and AcNAC4 acted as transcriptional activators and could bind to and activate AcACO1 promoter. CONCLUSION: All results unveiled that the ethylene-induced AcNAC3 and AcNAC4 were transcriptional activators, and might participate in kiwifruit ripening and ethylene biosynthesis through activating AcACO1, providing a new insight of ethylene synthetic regulation during kiwifruit ripening. © 2024 Society of Chemical Industry.
Asunto(s)
Actinidia , Etilenos , Frutas , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Factores de Transcripción , Actinidia/metabolismo , Actinidia/genética , Actinidia/crecimiento & desarrollo , Actinidia/química , Etilenos/metabolismo , Frutas/metabolismo , Frutas/crecimiento & desarrollo , Frutas/efectos de los fármacos , Frutas/genética , Frutas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Regiones Promotoras Genéticas , Reguladores del Crecimiento de las Plantas/farmacología , Reguladores del Crecimiento de las Plantas/metabolismo , Ciclopropanos/farmacología , Ciclopropanos/metabolismoRESUMEN
Zizania latifolia is an aquatic and medicinal plant with a long history of development in China and the East Asian region. The smut fungus "Ustilago esculenta" parasitizes Z. latifolia and induces culm expansion to form a vegetable named Jiaobai, which has a unique taste and nutritional attributes. However, the postharvest quality of water bamboo shoots is still a big challenge for farmers and merchants. This paper traced the origin, development process, and morphological characteristics of Z. latifolia. Subsequently, the compilation of the primary nutrients and bioactive substances are presented in context to their effects on ecology a postharvest storage and preservation methods. Furthermore, the industrial, environmental, and material science applications of Z. latifolia in the fields of industry were discussed. Finally, the primary objective of the review proposes future directions for research to support the development of Z. latifolia industry and aid in maximizing its value. To sum up, Z. latifolia, aside from its potential as material it can be utilized to make different productions and improve the existing applications. This paper provides an emerging strategy for researchers undertaking Z. latifolia.
RESUMEN
Luminol-based electrochemiluminescence (ECL) can be readily excited by various reactive oxygen species (ROS) electrogenerated with an oxygen reduction reaction (ORR). However, the multiple active intermediates involved in the ORR catalyzed with complex nanomaterials lead to recognizing the role of ROS still elusive. Moreover, suffering from the absence of the direct electrochemical oxidation of luminol at the cathode and poor transformation efficiency of O2 to ROS, the weak cathodic ECL emission of luminol is often neglected. Herein, owing to the tunable coordination environment and structure-dependent catalytic feature, single-atom catalysts (SACs) are employed to uncover the relationship between the intrinsic ORR activity and ECL behavior. Interestingly, the traditionally negligible cathodic ECL of luminol is first boosted (ca. 70-fold) owing to the combination of electrochemical ORR catalyzed via SACs and chemical oxidation of luminol. The boosted cathodic ECL emission exhibits electron-transfer pathway-dependent response by adjusting the surrounding environment of the center metal atoms in a controlled way to selectively produce different active intermediates. This work bridges the relationship between ORR performance and ECL behavior, which will guide the development of an amplified sensing platform through rational tailoring of the ORR activity of SACs and potential-resolved ECL assays based on the high-efficiency cathodic ECL reported.
Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Catálisis , Técnicas Electroquímicas , Electrodos , Mediciones Luminiscentes , Luminol , Oxígeno , Especies Reactivas de OxígenoRESUMEN
BACKGROUND: Vitamin D is an essential nutrient that has long been known to regulate skeletal growth and integrity. In models of major appendage regeneration, treatment with vitamin D analogs has been reported to improve aspects of zebrafish fin regeneration in specific disease or gene misexpression contexts, but also to disrupt pattern in regenerating salamander limbs. Recently, we reported strong mitogenic roles for vitamin D signaling in several zebrafish tissues throughout life stages, including epidermal cells and osteoblasts of adult fins. To our knowledge, molecular genetic approaches to dissect vitamin D function in appendage regeneration have not been described. RESULTS: Using a knock-in GFP reporter for the expression of the vitamin D target gene and negative regulator cyp24a1, we identified active vitamin D signaling in adult zebrafish fins during tissue homeostasis and regeneration. Transgenic expression of cyp24a1 or a dominant-negative vitamin D receptor (VDR) inhibited regeneration of amputated fins, whereas global vitamin D treatment accelerated regeneration. Using tissue regeneration enhancer elements, we found that local enhancement of VDR expression could improve regeneration with low doses of a vitamin D analog. CONCLUSIONS: Vitamin D signaling enhances the efficacy of fin regeneration in zebrafish.
Asunto(s)
Vitamina D , Pez Cebra , Aletas de Animales/metabolismo , Animales , Animales Modificados Genéticamente , Vitamina D/metabolismo , Vitamina D/farmacología , Pez Cebra/genética , Proteínas de Pez Cebra/metabolismoRESUMEN
BACKGROUND: MYB transcription factors (TFs) are common in plants and play important functions in growth and development, including fruit development and ripening. However, the role of MYB proteins in papaya ripening (fruit ripening and carotenoid biosynthesis) remains unclear. RESULTS: Two MYB genes were cloned from papaya pulp. They were named CpMYB1 (MYB44-like) and CpMYB2, and belong to the S22 subgroup of the R2R3-MYB family. Their expression levels decreased during fruit ripening. Subcellular localization analysis showed that both CpMYB1 and CpMYB2 were nuclear proteins, indicating that they might function in the nucleus. Moreover, CpMYB1 and CpMYB2 could bind to the promoters of cell-wall degradation genes (CpPME1, CpPME2, and CpPG5) and carotenoid biosynthesis genes (CpPDS2, CpPDS4, and CpCHY-b). Further research found that both CpMYB1 and CpMYB2 were transcriptional repressors, and they could suppress the activities of the promoters of CpPME1, CpPME2, CpPG5, CpPDS2, CpPDS4, and CpCHY-b. CONCLUSION: These results indicated that MYB TFs CpMYB1 and CpMYB2 might have a function in papaya fruit softening and carotenoid accumulation by regulating cell-wall degradation and carotenoid biosynthesis related genes, which provide a new view about the role of MYB TFs in fruit ripening. © 2020 Society of Chemical Industry.
Asunto(s)
Carica/metabolismo , Carotenoides/metabolismo , Pared Celular/metabolismo , Frutas/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Carica/química , Carica/genética , Carica/crecimiento & desarrollo , Pared Celular/genética , Frutas/química , Frutas/genética , Frutas/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Regiones Promotoras Genéticas , Factores de Transcripción/genéticaRESUMEN
Linoleic acid (LA; C18:2) and α-linolenic acid (ALA; C18:3) are two essential unsaturated fatty acids that play indispensable roles in maintaining membrane integrity in cold stress, and ω-3 fatty acid desaturases (FADs) are responsible for the transformation of LA into ALA. However, how this process is regulated at transcriptional and posttranscriptional levels remains largely unknown. In this study, an MYB transcription factor, MaMYB4, of a banana fruit was identified and found to target several ω-3 MaFADs, including MaFAD3-1, MaFAD3-3, MaFAD3-4 and MaFAD3-7, and repress their transcription. Intriguingly, the acetylation levels of histones H3 and H4 in the promoters of ω-3 MaFADs were elevated in response to cold stress, which was correlated with the enhancement in the transcription levels of ω-3 MaFADs and the ratio of ALA/LA. Moreover, a histone deacetylase MaHDA2 physically interacted with MaMYB4, thereby leading to the enhanced MaMYB4-mediated transcriptional repression of ω-3 MaFADs. Collectively, these data demonstrate that MaMYB4 might recruit MaHDA2 to repress the transcription of ω-3 MaFADs by affecting their acetylation levels, thus modulating fatty acid biosynthesis. Our findings provided new molecular insights into the regulatory mechanisms of fatty acid biosynthesis in cold stress in fruits.
Asunto(s)
Ácido Graso Desaturasas/metabolismo , Frutas/metabolismo , Histona Desacetilasas/metabolismo , Musa/metabolismo , Proteínas de Plantas/metabolismo , Respuesta al Choque por Frío/genética , Respuesta al Choque por Frío/fisiología , Frutas/genética , Musa/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
KEY MESSAGE: MaC2H2s are involved in cold stress response of banana fruit via repressing the transcription of MaICE1. Although C2H2 zinc finger proteins have been found to be involved in banana fruit ripening through transcriptional controlling of ethylene biosynthetic genes, their involvement in cold stress of banana remains elusive. In this study, another C2H2-ZFP gene from banana fruit was identified, which was named as MaC2H2-3. Gene expression analysis revealed that MaC2H2-1, MaC2H2-2 and MaC2H2-3 were cold inducible in the peel of banana during low temperature storage. MaC2H2-3 functions as a transcriptional repressor and localizes predominantly in nucleus. Particularly, promoters of MaC2H2-2 and MaC2H2-3 were noticeably activated by cold as well, further indicating the potential roles of C2H2 in cold stress of banana. Moreover, MaC2H2-2 and MaC2H2-3 significantly repressed the transcription of MaICE1, a key component in cold signaling pathway. Overall, these findings suggest that MaC2H2s may take part in controlling cold stress of banana through suppressing the transcription of MaICE1, providing new insight of the regulatory basis of C2H2 in cold stress.
Asunto(s)
Frío , Frutas/fisiología , Musa/fisiología , Proteínas de Plantas/metabolismo , Frutas/genética , Regulación de la Expresión Génica de las Plantas , Musa/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Papaya is an important tropical fruit with a rich source of carotenoids. The ripening of papaya is a physiological and metabolic process with remarkable changes including accumulation of carotenoids, which depends primarily on the action of ethylene. Ethylene response is mediated by a transcriptional cascade involving the transcription factor families of EIN3/EILs and ERFs. Although ERF members have been reported to control carotenoid production in Arabidopsis and tomato, whether EIN3/EILs are also involved in carotenoid biosynthesis during fruit ripening remains unclear. In this work, two EIN3 genes from papaya fruit, namely CpEIN3a and CpEIN3b, were studied, of which CpEIN3a was increased during fruit ripening, concomitant with the increase of transcripts of carotenoid biosynthesis-related genes including CpPDS2/4, CpZDS, CpLCY-e and CpCHY-b, and carotenoid content. Electrophoretic mobility shift assays (EMSAs) and transient expression analyses revealed that CpEIN3a was able to bind to the promoters of CpPDS4 and CpCHY-b, and promoted their transcription. Protein-protein interaction assays indicated that CpEIN3a physically interacted with another transcription factor CpNAC2, which acted as a transcriptional activator of CpPDS2/4, CpZDS, CpLCY-e and CpCHY-b by directly binding to their promoters. More importantly, the transcriptional activation abilities of CpPDS2/4, CpLCY-e and CpCHY-b were more pronounced following their interaction. Collectively, our findings suggest that CpEIN3a interacts with CpNAC2 and, individually or co-operatively, activates the transcription of a subset of carotenoid biosynthesis-related genes, providing new insights into the regulatory networks of carotenoid biosynthesis during papaya fruit ripening.
Asunto(s)
Carica/fisiología , Carotenoides/biosíntesis , Frutas/fisiología , Proteínas de Plantas/genética , Carica/genética , Carotenoides/genética , Ensayo de Cambio de Movilidad Electroforética , Frutas/genética , Regulación de la Expresión Génica de las Plantas , Liasas Intramoleculares/genética , Liasas Intramoleculares/metabolismo , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo , Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Proteínas de Plantas/metabolismo , Regiones Promotoras Genéticas , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
We report a simple, low-cost, and brand-new electrochemical lithography technique for replicating the template pattern with high resolution at â¼2 µm. The developed method is that the electroactive material is first deposited on the patterned conductive template by the electrochemical technique and then peeled by an adhesive tape/material. The resulting film with the precise pattern shows excellent mechanical and electronic properties and promises high prospect in designing flexible electronics. This interesting approach can be performed at ambient conditions and easily generalized to pattern various electroactive materials covering metal, alloy, nonmetal, salt, oxide, and composite on different types of substrates in several seconds to a few minutes, making the mass production of flexible/rigid/stretchable patterned thin films quite possible.
RESUMEN
Fruit ripening is a complex, genetically programmed process involving the action of critical transcription factors (TFs). Despite the established significance of dehydration-responsive element binding (DREB) TFs in plant abiotic stress responses, the involvement of DREBs in fruit ripening is yet to be determined. Here, we identified four genes encoding ripening-regulated DREB TFs in banana (Musa acuminata), MaDREB1, MaDREB2, MaDREB3, and MaDREB4, and demonstrated that they play regulatory roles in fruit ripening. We showed that MaDREB1-MaDREB4 are nucleus-localized, induced by ethylene and encompass transcriptional activation activities. We performed a genome-wide chromatin immunoprecipitation and high-throughput sequencing (ChIP-Seq) experiment for MaDREB2 and identified 697 genomic regions as potential targets of MaDREB2. MaDREB2 binds to hundreds of loci with diverse functions and its binding sites are distributed in the promoter regions proximal to the transcriptional start site (TSS). Most of the MaDREB2-binding targets contain the conserved (A/G)CC(G/C)AC motif and MaDREB2 appears to directly regulate the expression of a number of genes involved in fruit ripening. In combination with transcriptome profiling (RNA sequencing) data, our results indicate that MaDREB2 may serve as both transcriptional activator and repressor during banana fruit ripening. In conclusion, our study suggests a hierarchical regulatory model of fruit ripening in banana and that the MaDREB TFs may act as transcriptional regulators in the regulatory network.
Asunto(s)
Frutas/fisiología , Redes Reguladoras de Genes/genética , Musa/genética , Musa/fisiología , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Secuencia de Bases , Pared Celular/metabolismo , Deshidratación , Regulación hacia Abajo/genética , Frutas/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Motivos de Nucleótidos/genética , Proteínas de Plantas/aislamiento & purificación , Regiones Promotoras Genéticas/genética , Unión Proteica/genética , Fracciones Subcelulares/metabolismo , Factores de Transcripción/aislamiento & purificación , Activación Transcripcional/genéticaRESUMEN
Phytohormone ethylene controls diverse developmental and physiological processes such as fruit ripening via modulation of ethylene signaling pathway. Our previous study identified that ETHYLENE RESPONSE FACTOR11 (MaERF11), a transcription factor in the ethylene signaling pathway, negatively regulates the ripening of banana, but the mechanism for the MaERF11-mediated transcriptional regulation remains largely unknown. Here we showed that MaERF11 has intrinsic transcriptional repression activity in planta. Electrophoretic mobility shift assay and chromatin immunoprecipitation analyses demonstrated that MaERF11 binds to promoters of three ripening-related Expansin genes, MaEXP2, MaEXP7 and MaEXP8, as well as an ethylene biosynthetic gene MaACO1, via the GCC-box motif. Furthermore, expression patterns of MaACO1, MaEXP2, MaEXP7, and MaEXP8 genes are correlated with the changes of histone H3 and H4 acetylation level during fruit ripening. Moreover, we found that MaERF11 physically interacts with a histone deacetylase, MaHDA1, which has histone deacetylase activity, and the interaction significantly strengthens the MaERF11-mediated transcriptional repression of MaACO1 and Expansins Taken together, these findings suggest that MaERF11 may recruit MaHDA1 to its target genes and repress their expression via histone deacetylation.
Asunto(s)
Frutas/crecimiento & desarrollo , Frutas/genética , Regulación de la Expresión Génica de las Plantas , Histona Desacetilasas/metabolismo , Musa/metabolismo , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Acetilación , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Secuencia de Bases , Genes de Plantas , Histonas/metabolismo , Musa/genética , Musa/crecimiento & desarrollo , Regiones Promotoras Genéticas/genética , Unión Proteica , Transcripción GenéticaRESUMEN
In this work, we report a nanoscale multichannel closed bipolar electrode (BPE) array based on the poly(ethylene terephthalate) (PET) membrane for the first time. With our design, oxidants, coreactants, quenchers, and even biomarkers can be detected in a Ru(bpy)3(2+)/TPA (tripropylamine) electrochemiluminescence (ECL) system. The multichannel PET membrane was etched according to our desire by NaOH, and then Au nanofibers were decorated in the inner region of the channel as a BPE array. Using ECL as a signal readout, a series of targets including TPA, Ru(bpy)3(2+), dopamine, H2O2, alpha-fetoprotein (AFP), and carcino-embryonic antigen (CEA) can be detected with this device. The practical application of the proposed multichannel closed BPE array was verified in the detection of AFP and CEA in human serum with satisfying results. This kind of nanoscale device holds promising potential for multianalysis. More importantly, as the PET membrane used in this device can be etched with a desirable diameter (nano- to microscale) and different BPE array densities (ion tracks of 10(8)/cm(2), 10(6)/cm(2), 10(4)/cm(2)), our design can be served as a useful platform for future advances in nanoscale bipolar electrochemistry.
Asunto(s)
Antígeno Carcinoembrionario/sangre , Técnicas Electroquímicas/instrumentación , Luminiscencia , Mediciones Luminiscentes/métodos , Nanotecnología/instrumentación , alfa-Fetoproteínas/análisis , Electrodos , Humanos , Mediciones Luminiscentes/instrumentación , Tereftalatos Polietilenos/químicaRESUMEN
The DNA binding with one finger (Dof) proteins, a family of plant-specific transcription factors, are involved in a variety of plant biological processes. However, little information is available on their involvement in fruit ripening. We have characterized 25 MaDof genes from banana fruit (Musa acuminata), designated as MaDof1-MaDof25 Gene expression analysis in fruit subjected to different ripening conditions revealed that MaDofs were differentially expressed during different stages of ripening. MaDof10, 23, 24, and 25 were ethylene-inducible and nuclear-localized, and their transcript levels increased during fruit ripening. Moreover, yeast two-hybrid and bimolecular fluorescence complementation analyses demonstrated a physical interaction between MaDof23 and MaERF9, a potential regulator of fruit ripening reported in a previous study. We determined that MaDof23 is a transcriptional repressor, whereas MaERF9 is a transcriptional activator. We suggest that they might act antagonistically in regulating 10 ripening-related genes, including MaEXP1/2/3/5, MaXET7, MaPG1, MaPME3, MaPL2, MaCAT, and MaPDC, which are associated with cell wall degradation and aroma formation. Taken together, our findings provide new insight into the transcriptional regulation network controlling banana fruit ripening.
Asunto(s)
Frutas/crecimiento & desarrollo , Frutas/genética , Genes de Plantas , Musa/genética , Proteínas de Plantas/metabolismo , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Secuencia de Aminoácidos , Núcleo Celular/metabolismo , Regulación de la Expresión Génica de las Plantas , Musa/crecimiento & desarrollo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Unión Proteica , Transporte de Proteínas , Saccharomyces cerevisiae/metabolismo , Alineación de Secuencia , Análisis de Secuencia de ADN , Fracciones Subcelulares/metabolismo , Nicotiana/genética , Factores de Transcripción/química , Factores de Transcripción/genética , Activación Transcripcional/genéticaRESUMEN
KEY MESSAGE: CpERF9 controls papaya fruit ripening through transcriptional repression of cell-wall-modifying genes CpPME1/2 and CpPG5 by directly binding to their promoters. Papaya fruit ripening is an intricate and highly coordinated developmental process which is controlled by the action of ethylene and expression of numerous ethylene-responsive genes. Ethylene response factors (ERFs) representing the last regulators of ethylene-signaling pathway determine the specificities of ethylene response. However, knowledge concerning the transcriptional controlling mechanism of ERF-mediated papaya fruit ripening is limited. In the present work, a gene-encoding AP2/ERF protein with two ERF-associated amphiphilic repression (EAR) motifs, named CpERF9, was characterized from papaya fruit. CpERF9 was found to localize in nucleus, and possess transcriptional repression ability. CpERF9 expression steadily decreased during papaya fruit ripening, while several genes encoding pectin methylesterases (PMEs) and polygalacturonases (PGs), such as CpPME1/2 and CpPG5, were gradually increased, paralleling the decline of fruit firmness. Electrophoretic mobility shift assay (EMSA) demonstrated a specific binding of CpERF9 to promoters of CpPME1/2 and CpPG5, via the GCC-box motif. Transient expression of CpERF9 in tobacco repressed CpPME1/2 and CpPG5 promoter activities, which was depended on two EAR motifs of CpERF9 protein. Taken together, these findings suggest that papaya CpERF9 may act as a transcriptional repressor of several cell-wall modifying genes, such as CpPME1/2 and CpPG5, via directly binding to their promoters.
Asunto(s)
Carica/crecimiento & desarrollo , Carica/genética , Pared Celular/genética , Frutas/crecimiento & desarrollo , Frutas/genética , Genes de Plantas , Proteínas de Plantas/metabolismo , Proteínas Represoras/metabolismo , Transcripción Genética , Secuencia de Aminoácidos , Carica/citología , Ensayo de Cambio de Movilidad Electroforética , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/química , Proteínas de Plantas/genética , Regiones Promotoras Genéticas , Unión Proteica/genética , Protoplastos/metabolismo , Proteínas Represoras/química , Proteínas Represoras/genética , Análisis de Secuencia de Proteína , Fracciones Subcelulares/metabolismo , Nicotiana/metabolismoRESUMEN
Here we report a novel sensing strategy based on the closed bipolar system, in which we utilize a light emitting diode (LED) to connect a split bipolar electrode (BPE) and generate the luminescent signal in the presence of the target. With this design, we have constructed a BPE array for the quick and high-throughput determination of various electroactive substances with naked eyes. Due to the ultrahigh current efficiency of the closed bipolar system, the sample concentration can be reported by the luminous intensity of the inserted LED without the expensive luminescent agent and instruments. Besides, the stability of the signal is improved because of the electroluminescent property of the LED. To demonstrate the promising applications of the bipolar LED electrode (BP-LED-E), the rapid quantification of four model targets (H2O2, ascorbic acid (AA), glucose, and blood sugar) has been achieved based on different principles.
Asunto(s)
Ácido Ascórbico/análisis , Glucemia/análisis , Técnicas Electroquímicas , Glucosa/análisis , Peróxido de Hidrógeno/análisis , Luz , Electrodos , Sustancias Luminiscentes/químicaRESUMEN
The isthmic organiser located at the midbrain-hindbrain boundary (MHB) is the crucial developmental signalling centre responsible for patterning mesencephalic and metencephalic regions of the vertebrate brain. Formation and maintenance of the MHB is characterised by a hierarchical program of gene expression initiated by fibroblast growth factor 8 (Fgf8), coupled with cellular morphogenesis, culminating in the formation of the tectal-isthmo-cerebellar structures. Here, we show in zebrafish that one orthologue of the transcription factor grainy head-like 2 (Grhl2), zebrafish grhl2b plays a central role in both MHB maintenance and folding by regulating two distinct, non-linear pathways. Loss of grhl2b expression induces neural apoptosis and extinction of MHB markers, which are rescued by re-expression of engrailed 2a (eng2a), an evolutionarily conserved target of the Grhl family. Co-injection of sub-phenotypic doses of grhl2b and eng2a morpholinos reproduces the apoptosis and MHB marker loss, but fails to substantially disrupt formation of the isthmic constriction. By contrast, a novel direct grhl2b target, spec1, identified by phylogenetic analysis and confirmed by ChIP, functionally cooperates with grhl2b to induce MHB morphogenesis, but plays no role in apoptosis or maintenance of MHB markers. Collectively, these data show that MHB maintenance and morphogenesis are dissociable events regulated by grhl2b through diverse transcriptional targets.
Asunto(s)
Proteínas Portadoras/metabolismo , Mesencéfalo/crecimiento & desarrollo , Morfogénesis , Rombencéfalo/crecimiento & desarrollo , Factores de Transcripción/metabolismo , Proteínas de Pez Cebra/metabolismo , Pez Cebra/crecimiento & desarrollo , Animales , Apoptosis , Proteínas Portadoras/genética , Regulación del Desarrollo de la Expresión Génica/genética , Proteínas de Homeodominio/biosíntesis , Proteínas de Homeodominio/genética , Mesencéfalo/metabolismo , Morfolinos/genética , Proteínas del Tejido Nervioso/biosíntesis , Proteínas del Tejido Nervioso/genética , Filogenia , Rombencéfalo/metabolismo , Transducción de Señal , Factores de Transcripción/genética , Pez Cebra/genética , Proteínas de Pez Cebra/genéticaRESUMEN
In this work, a novel and universal ion sensing platform was presented, which enables the visual detection of various ions with high sensitivity and selectivity. Coaxial potential signals (millivolt-scale) of the sample from the self-referencing (SR) ion selective chip can be transferred into the ad620-based amplifier with an output of volt-scale potentials. The amplified voltage is high enough to drive a light emitting diode (LED), which can be used as an amplifier and indicator to report the sample information. With this double amplification device (light emitting diode-based self-referencing-ion selective field-effect transistor, LED-SR-ISFET), a tiny change of the sample concentration can be observed with a distinguishable variation of LED brightness by visual inspection. This LED-based luminescent platform provided a facile, low-cost, and rapid sensing strategy without the need of additional expensive chemiluminescence reagent and instruments. Moreover, the SR mode also endows this device excellent stability and reliability. With this innovative design, sensitive determination of K(+), H(+), and Cl(-) by the naked eye was achieved. It should also be noticed that this sensing strategy can easily be extended to other ions (or molecules) by simply integrating the corresponding ion (or molecule) selective electrode.