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1.
Annu Rev Biochem ; 87: 965-989, 2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29272143

RESUMO

Super-resolution optical imaging based on the switching and localization of individual fluorescent molecules [photoactivated localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), etc.] has evolved remarkably over the last decade. Originally driven by pushing technological limits, it has become a tool of biological discovery. The initial demand for impressive pictures showing well-studied biological structures has been replaced by a need for quantitative, reliable data providing dependable evidence for specific unresolved biological hypotheses. In this review, we highlight applications that showcase this development, identify the features that led to their success, and discuss remaining challenges and difficulties. In this context, we consider the complex topic of defining resolution for this imaging modality and address some of the more common analytical methods used with this data.


Assuntos
Imagem Individual de Molécula/métodos , Algoritmos , Animais , Análise por Conglomerados , Análise de Fourier , Humanos , Imageamento Tridimensional , Modelos Biológicos , Estrutura Molecular , Nanotecnologia , Imagem Individual de Molécula/estatística & dados numéricos , Processos Estocásticos
2.
Mol Cell ; 77(1): 39-50.e10, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31735642

RESUMO

CRISPR-Cas systems encode RNA-guided surveillance complexes to find and cleave invading DNA elements. While it is thought that invaders are neutralized minutes after cell entry, the mechanism and kinetics of target search and its impact on CRISPR protection levels have remained unknown. Here, we visualize individual Cascade complexes in a native type I CRISPR-Cas system. We uncover an exponential relation between Cascade copy number and CRISPR interference levels, pointing to a time-driven arms race between invader replication and target search, in which 20 Cascade complexes provide 50% protection. Driven by PAM-interacting subunit Cas8e, Cascade spends half its search time rapidly probing DNA (∼30 ms) in the nucleoid. We further demonstrate that target DNA transcription and CRISPR arrays affect the integrity of Cascade and affect CRISPR interference. Our work establishes the mechanism of cellular DNA surveillance by Cascade that allows the timely detection of invading DNA in a crowded, DNA-packed environment.


Assuntos
Bactérias/genética , Proteínas Associadas a CRISPR/genética , Sistemas CRISPR-Cas/genética , DNA/genética , RNA Guia de Cinetoplastídeos/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Replicação do DNA/genética , Dosagem de Genes/genética
3.
Mol Cell ; 75(5): 933-943.e6, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31326272

RESUMO

Target RNA binding to crRNA-bound type III-A CRISPR-Cas multi-subunit Csm surveillance complexes activates cyclic-oligoadenylate (cAn) formation from ATP subunits positioned within the composite pair of Palm domain pockets of the Csm1 subunit. The generated cAn second messenger in turn targets the CARF domain of trans-acting RNase Csm6, triggering its HEPN domain-based RNase activity. We have undertaken cryo-EM studies on multi-subunit Thermococcus onnurineus Csm effector ternary complexes, as well as X-ray studies on Csm1-Csm4 cassette, both bound to substrate (AMPPNP), intermediates (pppAn), and products (cAn), to decipher mechanistic aspects of cAn formation and release. A network of intermolecular hydrogen bond alignments accounts for the observed adenosine specificity, with ligand positioning dictating formation of linear pppAn intermediates and subsequent cAn formation by cyclization. We combine our structural results with published functional studies to highlight mechanistic insights into the role of the Csm effector complex in mediating the cAn signaling pathway.


Assuntos
Nucleotídeos de Adenina/química , Proteínas Arqueais/química , Sistemas CRISPR-Cas , Oligorribonucleotídeos/química , Ribonucleases/química , Sistemas do Segundo Mensageiro , Thermococcus/química , Nucleotídeos de Adenina/metabolismo , Proteínas Arqueais/metabolismo , Microscopia Crioeletrônica , Oligorribonucleotídeos/metabolismo , Ribonucleases/metabolismo , Thermococcus/metabolismo , Thermococcus/ultraestrutura
4.
Proc Natl Acad Sci U S A ; 121(28): e2318029121, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38950360

RESUMO

Indonesia has experienced rapid primary forest loss, second only to Brazil in modern history. We examined the fates of Indonesian deforested areas, immediately after clearing and over time, to quantify deforestation drivers in Indonesia. Using time-series satellite data, we tracked degradation and clearing events in intact and degraded natural forests from 1991 to 2020, as well as land use trajectories after forest loss. While an estimated 7.8 Mha (SE = 0.4) of forest cleared during this period had been planted with oil palms by 2020, another 8.8 Mha (SE = 0.4) remained unused. Of the 28.4 Mha (SE = 0.7) deforested, over half were either initially left idle or experienced crop failure before a land use could be detected, and 44% remained unused for 5 y or more. A majority (54%) of these areas were cleared mechanically (not by escaped fires), and in cases where idle lands were eventually converted to productive uses, oil palm plantations were by far the most common outcome. The apparent deliberate creation of idle deforested land in Indonesia and subsequent conversion of idle areas to oil palm plantations indicates that speculation and land banking for palm oil substantially contribute to forest loss, although failed plantations could also contribute to this dynamic. We also found that in Sumatra, few lowland forests remained, suggesting that a lack of remaining forest appropriate for palm oil production, together with an extensive area of banked deforested land, may partially explain slowing forest loss in Indonesia in recent years.


Assuntos
Conservação dos Recursos Naturais , Florestas , Indonésia , Árvores/crescimento & desenvolvimento , Agricultura
5.
Proc Natl Acad Sci U S A ; 121(17): e2307220121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38621138

RESUMO

The expansion of the oil palm industry in Indonesia has improved livelihoods in rural communities, but comes at the cost of biodiversity and ecosystem degradation. Here, we investigated ways to balance ecological and economic outcomes of oil palm cultivation. We compared a wide range of production systems, including smallholder plantations, industrialized company estates, estates with improved agronomic management, and estates with native tree enrichment. Across all management types, we assessed multiple indicators of biodiversity, ecosystem functions, management, and landscape structure to identify factors that facilitate economic-ecological win-wins, using palm yields as measure of economic performance. Although, we found that yields in industrialized estates were, on average, twice as high as those in smallholder plantations, ecological indicators displayed substantial variability across systems, regardless of yield variations, highlighting potential for economic-ecological win-wins. Reducing management intensity (e.g., mechanical weeding instead of herbicide application) did not lower yields but improved ecological outcomes at moderate costs, making it a potential measure for balancing economic and ecological demands. Additionally, maintaining forest cover in the landscape generally enhanced local biodiversity and ecosystem functioning within plantations. Enriching plantations with native trees is also a promising strategy to increase ecological value without reducing productivity. Overall, we recommend closing yield gaps in smallholder cultivation through careful intensification, whereas conventional plantations could reduce management intensity without sacrificing yield. Our study highlights various pathways to reconcile the economics and ecology of palm oil production and identifies management practices for a more sustainable future of oil palm cultivation.


Assuntos
Arecaceae , Óleos Industriais , Ecossistema , Florestas , Biodiversidade , Agricultura , Árvores , Óleo de Palmeira , Conservação dos Recursos Naturais
6.
Mol Cell ; 67(2): 282-293.e7, 2017 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-28712725

RESUMO

The eukaryotic genome is organized within cells as chromatin. For proper information output, higher-order chromatin structures can be regulated dynamically. How such structures form and behave in various cellular processes remains unclear. Here, by combining super-resolution imaging (photoactivated localization microscopy [PALM]) and single-nucleosome tracking, we developed a nuclear imaging system to visualize the higher-order structures along with their dynamics in live mammalian cells. We demonstrated that nucleosomes form compact domains with a peak diameter of ∼160 nm and move coherently in live cells. The heterochromatin-rich regions showed more domains and less movement. With cell differentiation, the domains became more apparent, with reduced dynamics. Furthermore, various perturbation experiments indicated that they are organized by a combination of factors, including cohesin and nucleosome-nucleosome interactions. Notably, we observed the domains during mitosis, suggesting that they act as building blocks of chromosomes and may serve as information units throughout the cell cycle.


Assuntos
Montagem e Desmontagem da Cromatina , Heterocromatina/metabolismo , Microscopia de Vídeo/métodos , Mitose , Nucleossomos/metabolismo , Animais , Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular , Proteínas Cromossômicas não Histona/metabolismo , Cromossomos Humanos , Células HCT116 , Células HeLa , Heterocromatina/química , Humanos , Camundongos , Movimento (Física) , Conformação de Ácido Nucleico , Nucleossomos/química , Conformação Proteica , Interferência de RNA , Relação Estrutura-Atividade , Fatores de Tempo , Transcrição Gênica , Transfecção , Coesinas
7.
Mol Cell Proteomics ; 22(8): 100593, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37328063

RESUMO

Proteins containing a CAAX motif at the C-terminus undergo prenylation for localization and activity and include a series of key regulatory proteins, such as RAS superfamily members, heterotrimeric G proteins, nuclear lamina protein, and several protein kinases and phosphatases. However, studies of prenylated proteins in esophageal cancer are limited. Here, through research on large-scale proteomic data of esophageal cancer in our laboratory, we found that paralemmin-2 (PALM2), a potential prenylated protein, was upregulated and associated with poor prognosis in patients. Low-throughput verification showed that the expression of PALM2 in esophageal cancer tissues was higher than that in their paired normal esophageal epithelial tissues, and it was generally expressed in the membrane and cytoplasm of esophageal cancer cells. PALM2 interacted with the two subunits of farnesyl transferase (FTase), FNTA and FNTB. Either the addition of an FTase inhibitor or mutation in the CAAX motif of PALM2 (PALM2C408S) impaired its membranous localization and reduced the membrane location of PALM2, indicating PALM2 was prenylated by FTase. Overexpression of PALM2 enhanced the migration of esophageal squamous cell carcinoma cells, whereas PALM2C408S lost this ability. Mechanistically, PALM2 interacted with the N-terminal FERM domain of ezrin of the ezrin/radixin/moesin (ERM) family. Mutagenesis indicated that lysine residues K253/K254/K262/K263 in ezrin's FERM domain and C408 in PALM2's CAAX motif were important for PALM2/ezrin interaction and ezrin activation. Knockout of ezrin prevented enhanced cancer cell migration by PALM2 overexpression. PALM2, depending on its prenylation, increased both ezrin membrane localization and phosphorylation of ezrin at Y146. In summary, prenylated PALM2 enhances the migration of cancer cells by activating ezrin.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Movimento Celular , Neoplasias Esofágicas/metabolismo , Proteômica
8.
Br J Haematol ; 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39226157

RESUMO

Large language models (LLMs) have significantly impacted various fields with their ability to understand and generate human-like text. This study explores the potential benefits and limitations of integrating LLMs, such as ChatGPT, into haematology practices. Utilizing systematic review methodologies, we analysed studies published after 1 December 2022, from databases like PubMed, Web of Science and Scopus, and assessing each for bias with the QUADAS-2 tool. We reviewed 10 studies that applied LLMs in various haematology contexts. These models demonstrated proficiency in specific tasks, such as achieving 76% diagnostic accuracy for haemoglobinopathies. However, the research highlighted inconsistencies in performance and reference accuracy, indicating variability in reliability across different uses. Additionally, the limited scope of these studies and constraints on datasets could potentially limit the generalizability of our findings. The findings suggest that, while LLMs provide notable advantages in enhancing diagnostic processes and educational resources within haematology, their integration into clinical practice requires careful consideration. Before implementing them in haematology, rigorous testing and specific adaptation are essential. This involves validating their accuracy and reliability across different scenarios. Given the field's complexity, it is also critical to continuously monitor these models and adapt them responsively.

9.
BMC Plant Biol ; 24(1): 910, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39349997

RESUMO

BACKGROUND: Oil palm (Elaeis guineensis Jacq.) is a very important tropical woody oil plant with high commercial and ornamental value. The exocarp of the oil palm fruit is rich in anthocyanosides and proanthocyanidins, which not only give it a bright colour, but also mark the maturity of the fruit. The study of the dynamic change pattern of anthocyanoside content and important anthocyanoside metabolism-related regulatory genes during oil palm ripening is conducive to the improvement of the ornamental value of oil palm and the determination of the optimal harvesting period of the fruits. METHODS: We analyzed the virescens oil palm (AS) and nigrescens oil palm (AT) at 95 days (AS1, AT1), 125 days (AS2, AT2) and 185 days (AS3, AT3) after pollination were used as experimental materials for determining the changes in the total amount of anthocyanins as well as their metabolomics and transcriptomics studies by using the LC-MS/MS technique and RNA-Seq technique. RESULT: The results showed that the total anthocyanin content decreased significantly from AS1 (119 µg/g) to AS3 (23 µg/g), and from AT1 (1302 µg/g) to AT3 (170 µg/g), indicating a clear decreasing trend during fruit development. Among them, the higher flavonoids in AS and AT included anthocyanins such as peonidin-3-O-rutinoside (H35), pelargonidin-3-O-rutinoside (H21), and cyanidin-3-O-glucoside (H7), as well as condensed tannins such as procyanidin B2 (H47), procyanidin C1 (H49), and procyanidin B3 (H48). Notably, nine genes involved in the anthocyanin biosynthetic pathway exhibited up-regulated expression during the pre-development stage of oil palm fruits, particularly during the AS1 and AT1 periods. These genes include: Chalcone synthase (CHS; LOC105036364); Flavanone 3-hydroxylase (F3H; LOC105054663); Dihydroflavonol 4-reductase (DFR; LOC105040724, LOC105048473); Anthocyanidin synthase (ANS; LOC105035842), UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT; LOC105039612); Flavonoid 3',5'-hydroxylase (F3'5'H; LOC105036086, LOC105044124, LOC105045493). In contrast, five genes demonstrated up-regulated expression as the fruits developed, specifically during the AS3 and AT3 periods. These genes include: Chalcone synthase (CHS; LOC105036921, LOC105035716); Chalcone isomerase (CHI; LOC105045978); UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT; LOC105046326); Flavonoid 3'-hydroxylase (F3'H; LOC105036086). CONCLUSION: Most of differentially expressed genes exhibited up-regulation during the early stages of fruit development, which may contribute to the elevated anthocyanin content observed in oil palm fruits of both types during the pre-developmental period. Furthermore, the expression levels of most genes were found to be higher in the AT fruit type compared to the AS fruit type, suggesting that the differential expression of these genes may be a key factor underlying the differences in anthocyanoside production in the exocarp of oil palm fruits from these two fruit types. The findings of this study provide a theoretical foundation for the identification and characterization of genes involved in anthocyanin synthesis in oil palm fruits, as well as the development of novel variations using molecular biology approaches.


Assuntos
Antocianinas , Arecaceae , Frutas , Perfilação da Expressão Gênica , Metabolômica , Antocianinas/metabolismo , Antocianinas/biossíntese , Frutas/genética , Frutas/metabolismo , Frutas/crescimento & desenvolvimento , Arecaceae/genética , Arecaceae/metabolismo , Arecaceae/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Transcriptoma , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Metaboloma
10.
BMC Plant Biol ; 24(1): 225, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38539110

RESUMO

BACKGROUND: Plants are considered the primary source of many principal bioactive compounds that have been utilized in a wide range of applications including the pharmaceutical and biotechnological industries. Therefore, there is an imperative need to modulate the production of natural bioactive components. The present study aimed to determine the importance of dried and pulverized date palm seeds (DPS) as a natural elicitor for the synthesis of secondary metabolites in Lotus arabicus L. RESULTS: The presence of various antioxidant compounds, simple sugars, amino acids, fatty acids and reasonable mineral contents was distinct in the phytochemical characterization of DPS. The major components detected in DPS analysis were the 5-(hydroxymethyl) furfural and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyranone. The induced callus of L. arabicus (seven weeks old) was supplemented with DPS at different concentrations (0, 2, 4, 8 and 10 g/l) in culture media. Treatment with 8 g/l DPS induced the highest antioxidant capacity, ascorbic acid content and secondary metabolites (total phenolics and flavonoids) in the produced callus. Stress biomarkers (hydrogen peroxide and malondialdehyde) were found in the control ranges except at 10 g/l DPS. The expression patterns of key genes involoved in secondary metabolism modulation, such as phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), flavonol synthase (FLS) and deoxyxylulose phosphate reductoisomerase (DXR), were triggered after DPS treatments. Moreover, the quantitative profiling of phenolic and flavonoid compounds showed that supplementation with DPS, especially at 8 g/l, led to pronounced increases in most of the measured compounds. CONCLUSION: The marked upregulation of eliciting-responsive genes and overproduction of secondary metabolites provide molecular-based evidence for intensifying the principal pathways of phenylpropanoid, flavonoid and terpenoid biosynthesis. Overall, the present in vitro study highlights the stimulating capacity of DPS utilization to improve the bioactive components of L. arabicus at the physiological and molecular levels, enhancing its potential as a medicinal herb.


Assuntos
Lotus , Phoeniceae , Antioxidantes/metabolismo , Lotus/metabolismo , Phoeniceae/metabolismo , Pós , Flavonoides/metabolismo , Fenóis/metabolismo , Sementes/metabolismo
11.
New Phytol ; 243(3): 1247-1261, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38837425

RESUMO

The afila (af) mutation causes the replacement of leaflets by a branched mass of tendrils in the compound leaves of pea - Pisum sativum L. This mutation was first described in 1953, and several reports of spontaneous af mutations and induced mutants with a similar phenotype exist. Despite widespread introgression into breeding material, the nature of af and the origin of the alleles used remain unknown. Here, we combine comparative genomics with reverse genetic approaches to elucidate the genetic determinants of af. We also investigate haplotype diversity using a set of AfAf and afaf cultivars and breeding lines and molecular markers linked to seven consecutive genes. Our results show that deletion of two tandemly arranged genes encoding Q-type Cys(2)His(2) zinc finger transcription factors, PsPALM1a and PsPALM1b, is responsible for the af phenotype in pea. Eight haplotypes were identified in the af-harbouring genomic region on chromosome 2. These haplotypes differ in the size of the deletion, covering more or less genes. Diversity at the af locus is valuable for crop improvement and sheds light on the history of pea breeding for improved standing ability. The results will be used to understand the function of PsPALM1a/b and to transfer the knowledge for innovation in related crops.


Assuntos
Haplótipos , Fenótipo , Pisum sativum , Melhoramento Vegetal , Pisum sativum/genética , Haplótipos/genética , Genes de Plantas , Proteínas de Plantas/genética , Mutação/genética , Folhas de Planta/genética , Cruzamento , Fatores de Transcrição/genética , Variação Genética
12.
Glob Chang Biol ; 30(8): e17436, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39162201

RESUMO

Measurements of net primary productivity (NPP) and litter decomposition from tropical peatlands are severely lacking, limiting our ability to parameterise and validate models of tropical peatland development and thereby make robust predictions of how these systems will respond to future environmental and climatic change. Here, we present total NPP (i.e., above- and below-ground) and decomposition data from two floristically and structurally distinct forested peatland sites within the Pastaza Marañón Foreland Basin, northern Peru, the largest tropical peatland area in Amazonia: (1) a palm (largely Mauritia flexuosa) dominated swamp forest and (2) a hardwood dominated swamp forest (known as 'pole forest', due to the abundance of thin-stemmed trees). Total NPP in the palm forest and hardwood-dominated forest (9.83 ± 1.43 and 7.34 ± 0.84 Mg C ha-1 year-1, respectively) was low compared with values reported for terra firme forest in the region (14.21-15.01 Mg C ha-1 year-1) and for tropical peatlands elsewhere (11.06 and 13.20 Mg C ha-1 year-1). Despite the similar total NPP of the two forest types, there were considerable differences in the distribution of NPP. Fine root NPP was seven times higher in the palm forest (4.56 ± 1.05 Mg C ha-1 year-1) than in the hardwood forest (0.61 ± 0.22 Mg C ha-1 year-1). Above-ground palm NPP, a frequently overlooked component, made large contributions to total NPP in the palm-dominated forest, accounting for 41% (14% in the hardwood-dominated forest). Conversely, Mauritia flexuosa litter decomposition rates were the same in both plots: highest for leaf material, followed by root and then stem material (21%, 77% and 86% of mass remaining after 1 year respectively for both plots). Our results suggest potential differences in these two peatland types' responses to climate and other environmental changes and will assist in future modelling studies of these systems.


Mediciones de la productividad primaria neta (PPN) y la descomposición de materia orgánica de las turberas tropicales son escasas, lo que limita nuestra capacidad para parametrizar y validar modelos de desarrollo de las turberas tropicales y, en consecuencia, realizar predicciones sólidas sobre la respuesta de estos sistemas ante futuros cambios ambientales y climáticos. En este estudio, presentamos datos de PPN total (es decir, biomasa aérea y subterránea) y descomposición de la materia orgánica colectada en dos turberas boscosas con características florísticas y estructurales contrastantes dentro de la cuenca Pastaza Marañón al norte del Perú, el área de turberas tropicales más grande de la Amazonia: (1) un bosque pantanoso dominado por palmeras (principalmente Mauritia flexuosa) y (2) un bosque pantanosos dominado por árboles leñosos de tallo delgado (conocido como 'varillal hidromórfico'). La PPN total en el bosque de palmeras y el varillal hidromórfico (9,83 ± 1,43 y 7,34 ± 0,84 Mg C ha­1 año­1 respectivamente) fue baja en comparación con los valores reportados para los bosques de tierra firme en la región (14,21­15,01 Mg C ha­1 año­1) y para turberas tropicales en otros lugares (11,06 y 13,20 Mg C ha­1 año­1). A pesar de que la PPN total fue similar en ambos tipos de bosque, hubo diferencias considerables en la distribución de la PPN. La PPN de las raíces finas fue siete veces mayor en el bosque de palmeras (4,56 ± 1,05 Mg C ha­1 año­1) que en el varillal hidromórfico (0,61 ± 0,22 Mg C ha­1 año­1). La PPN de la biomasa aérea de las palmeras, un componente ignorado frecuentemente, contribuyó en gran medida a la PPN total del bosque de palmeras, representando el 41% (14% en el varillal hidromórfico). Por el contrario, la tasa de descomposición de materia orgánica de Mauritia flexuosa fue la misma en ambos sitios: la más alta corresponde a la hojarasca, seguida por las raíces y luego el tallo (21%, 77% y 86% de la masa restante después de un año, respectivamente para ambos sitios). Nuestros resultados sugieren diferencias potenciales en la respuesta de estos dos tipos de turberas al clima y otros cambios ambientales, y ayudarán en futuros estudios de modelamiento de estos sistemas.


Assuntos
Florestas , Peru , Áreas Alagadas , Solo/química , Folhas de Planta/metabolismo , Clima Tropical
13.
Anal Biochem ; 684: 115372, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-37940013

RESUMO

Because of the heterogeneity among seedlings of outbreeding species, the use of seedling tissues as a source of DNA is unsuitable for the genomic characterization of elite germplasms. High-quality DNA, free of RNA, proteins, polysaccharides, secondary metabolites, and shearing, is mandatory for downstream molecular biology applications, especially for next-generation genome sequencing and pangenome analysis aiming to capture the complete genetic diversity within a species. The study aimed to accomplish an efficient protocol for the extraction of high-quality DNA suitable for diverse plant species/tissues. We describe a reliable, and consistent protocol suitable for the extraction of DNA from 42 difficult-to-extract plant species belonging to 33 angiosperm (monocot and dicot) families, including tissues such as seeds, roots, endosperm, and flower/fruit tissues. The protocol was first optimized for the outbreeding recalcitrant trees viz., Prosopis cineraria, Conocarpus erectus, and Phoenix dactylifera, which are rich in proteins, polysaccharides, and secondary metabolites, and the quality of the extracted DNA was confirmed by downstream applications. Nine procedures were attempted to extract high-quality, impurities-free DNA from these three plant species. Extraction of the ethanol-precipitated DNA from cetyltrimethylammonium bromide (CTAB) protocol using sodium dodecyl sulfate (SDS) buffer, i.e., the extraction using a cationic (CTAB) detergent followed by an anionic (SDS) detergent was the key for high yield and high purity (1.75-1.85 against A260/280 and an A260/230 ratio of >2) DNA. A vice versa extraction procedure, i.e., SDS buffer followed by CTAB buffer, and also CTAB buffer followed by CTAB, did not yield good-quality DNA. PCR (using different primers) and restriction endonuclease digestion of the DNA extracted from these three plants validated the protocol. The accomplishment of the genome of P. cineraria using the DNA extracted using the modified protocol confirmed its applicability to genomic studies. The optimized protocol successful in extracting high-quality DNA from diverse plant species/tissues extends its applicability and is useful for accomplishing genome sequences of elite germplasm of recalcitrant plant species with quality reads.


Assuntos
DNA , Detergentes , Humanos , Cetrimônio , Plantas/genética , Genômica , Polissacarídeos , DNA de Plantas/genética
14.
Genetica ; 152(1): 11-29, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38099985

RESUMO

The African grass or Nile rat (NR) (Arvicanthis niloticus) is a herbivorous diurnal rodent which is used as a biological model for research on type 2 diabetes mellitus (T2DM) and the circadian rhythm. Similar to humans, male NRs develop T2DM with high-carbohydrate diets. The NR thus provides a unique opportunity to identify the nutritional and underlying genetic factors that characterise human T2DM, as well as the effects of potential anti-diabetic phytochemicals such as Water-Soluble Palm Fruit Extract. Whole genome sequencing (WGS) could help identify possible genetic causes why NRs spontaneously develop T2DM in captivity. In this study, we performed WGS on a hepatic deoxyribonucleic acid (DNA) sample isolated from a male NR using PacBio high-fidelity long-read sequencing. The WGS data obtained were then de novo assembled and annotated using PacBio HiFi isoform sequencing (Iso-Seq) data as well as previous Illumina RNA sequencing (RNA-Seq) data. Genes related to insulin and circadian rhythm pathways were present in the NR genome, similar to orthologues in the rat, mouse and human genomes. T2DM development in the NR is thus most likely not attributable to structural differences in these genes when compared to other biological models. Further studies are warranted to gain additional insights on the genetic-environmental factors which underlie the genetic permissiveness of NRs to develop T2DM.


Assuntos
Diabetes Mellitus Tipo 2 , Insulina , Humanos , Camundongos , Animais , Masculino , Murinae/genética , Diabetes Mellitus Tipo 2/genética , Ritmo Circadiano/genética
15.
Transgenic Res ; 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39120800

RESUMO

Root-specific or preferential promoters are essential to genetically modify plants with beneficial root traits. We have characterised the promoter from an oil palm metallothionein gene (EgMT) and performed a serial 5' deletion analysis to identify the region(s) essential for transgenes expression in roots. Stable functional characterisation of tobacco transgenic lines using the T1 generation showed that a deletion construct, designated as RSP-2D (1107 bp), directed strong GUS expression at all stages of root development, particularly in mature roots. Other constructs, RSP-2A (2481 bp) and RSP-2C (1639 bp), drove GUS expression in roots with an intensity lower than RSP-2D. The promoter activity was also detectable in seed pods and immature seeds, albeit at lower levels than CaMV35S. The promoter activity may also be induced by wounding as intact GUS staining was observed at the flower- and leaf-cutting sites of T1 samples carrying either RSP-2C or RSP-2D constructs. The promoter sequence contains cis-acting elements that may act as negative regulators and be responsible for root specificity. The results further indicated that the 5' UTR and ATATT sequences are essential for strong promoter activity. This study highlights the potential of RSP-2D promoter as a tool for modifying root traits through genetic engineering.

16.
Ann Bot ; 134(2): 263-282, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38687211

RESUMO

BACKGROUND AND AIMS: Palm fossils are often used as evidence for warm and wet palaeoenvironments, reflecting the affinities of most modern palms. However, several extant palm lineages tolerate cool and/or arid climates, making a clear understanding of the taxonomic composition of ancient palm communities important for reliable palaeoenvironmental inference. However, taxonomically identifiable palm fossils are rare and often confined to specific facies. Although the resolution of taxonomic information they provide remains unclear, phytoliths (microscopic silica bodies) provide a possible solution because of their high preservation potential under conditions where other plant fossils are scarce. We thus evaluate the taxonomic and palaeoenvironmental utility of palm phytoliths. METHODS: We quantified phytolith morphology of 97 modern palm and other monocot species. Using this dataset, we tested the ability of five common discriminant methods to identify nine major palm clades. We then compiled a dataset of species' climate preferences and tested if they were correlated with phytolith morphology using a phylogenetic comparative approach. Finally, we reconstructed palm communities and palaeoenvironmental conditions at six fossil sites. KEY RESULTS: Best-performing models correctly identified phytoliths to their clade of origin only 59 % of the time. Although palms were generally distinguished from non-palms, few palm clades were highly distinct, and phytolith morphology was weakly correlated with species' environmental preferences. Reconstructions at all fossil sites suggested that palm communities were dominated by Trachycarpeae and Areceae, with warm, equable climates and high, potentially seasonal rainfall. However, fossil site reconstructions had high uncertainty and often conflicted with other climate proxies. CONCLUSIONS: While phytolith morphology provides some distinction among palm clades, caution is warranted. Unlike prior spatially restricted studies, our geographically and phylogenetically broad study indicates phytolith morphology may not reliably differentiate most palm taxa in deep time. Nevertheless, it reveals distinct clades, including some likely to be palaeoenvironmentally informative.


Assuntos
Arecaceae , Evolução Biológica , Fósseis , Filogenia , Arecaceae/anatomia & histologia , Arecaceae/fisiologia , Fósseis/anatomia & histologia , Clima
17.
Br J Nutr ; 131(4): 553-566, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-37699661

RESUMO

Sterol regulatory element-binding protein 2 (SREBP2) is considered to be a major regulator to control cholesterol homoeostasis in mammals. However, the role of SREBP2 in teleost remains poorly understand. Here, we explored the molecular characterisation of SREBP2 and identified SREBP2 as a key modulator for 3-hydroxy-3-methylglutaryl-coenzyme A reductase and 7-dehydrocholesterol reductase, which were rate-limiting enzymes of cholesterol biosynthesis. Moreover, dietary palm oil in vivo or palmitic acid (PA) treatment in vitro elevated cholesterol content through triggering SREBP2-mediated cholesterol biosynthesis in large yellow croaker. Furthermore, our results also found that PA-induced activation of SREBP2 was dependent on the stimulating of endoplasmic reticulum stress (ERS) in croaker myocytes and inhibition of ERS by 4-Phenylbutyric acid alleviated PA-induced SREBP2 activation and cholesterol biosynthesis. In summary, our findings reveal a novel insight for understanding the role of SREBP2 in the regulation of cholesterol metabolism in fish and may deepen the link between dietary fatty acid and cholesterol biosynthesis.


Assuntos
Gorduras Insaturadas na Dieta , Perciformes , Animais , Colesterol/metabolismo , Estresse do Retículo Endoplasmático , Músculos/metabolismo , Óleo de Palmeira/farmacologia , Perciformes/metabolismo , Proteína de Ligação a Elemento Regulador de Esterol 2/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/metabolismo
18.
Conserv Biol ; 38(1): e14172, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37650444

RESUMO

The expansion of oil palm plantations has led to land-use change and deforestation in the tropics, which has affected biodiversity. Although the impacts of the crop on terrestrial biodiversity have been extensively reviewed, its effects on freshwater biodiversity remain relatively unexplored. We reviewed the research assessing the impacts of forest-to-oil palm conversion on freshwater biota and the mitigating effect of riparian buffers on these impacts. We searched for studies comparing taxa richness, species abundance, and community composition of macroinvertebrates, amphibians, and fish in streams in forests (primary and disturbed) and oil palm plantations with and without riparian buffers. Then, we conducted a meta-analysis to quantify the overall effect of the land-use change on the 3 taxonomic groups. Twenty-nine studies fulfilled the inclusion criteria. On average, plantations lacking buffers hosted 44% and 19% fewer stream taxa than primary and disturbed forests, respectively. Stream taxa on plantations with buffers were 24% lower than in primary forest and did not differ significantly from disturbed forest. In contrast, stream community composition differed between forests and plantations regardless of the presence of riparian buffers. These differences were attributed to agrochemical use and altered environmental conditions in the plantations, including temperature changes, worsened water conditions, microhabitat loss, and food and shelter depletion. On aggregate, abundance did not differ significantly among land uses because increases in generalist species offset the population decline of vulnerable forest specialists in the plantation. Our results reveal significant impacts of forest-to-oil palm conversion on freshwater biota, particularly taxa richness and composition (but not aggregate abundance). Although preserving riparian buffers in the plantations can mitigate the loss of various aquatic species, it cannot conserve primary forest communities. Therefore, safeguarding primary forests from the oil palm expansion is crucial, and further research is needed to address riparian buffers as a promising mitigation strategy in agricultural areas.


Metaanálisis contrastando la biodiversidad de agua dulce en los bosques y las plantaciones de palma de aceite con o sin bosques ribereños Resumen La expansión de las plantaciones de palma de aceite ha derivado en cambios en el uso de suelo y deforestación en los trópicos, afectando a la biodiversidad. Existe una revisión extensa del impacto de este cultivo sobre la biodiversidad terrestre, pero sus efectos sobre la biodiversidad de agua dulce todavía no están muy documentados. Revisamos las investigaciones que han evaluado el impacto de la conversión de bosque a plantación de palma de aceite sobre la biota de agua dulce y el efecto mitigante que tienen los bosques ribereños sobre este impacto. Buscamos estudios que compararan la riqueza de taxones, abundancia de especies y composición comunitaria de los macroinvertebrados, anfibios y peces en los riachuelos de los bosques (primarios y perturbados) y los sembradíos de palma de aceite con y sin bosques ribereños. Después realizamos un metaanálisis para cuantificar el efecto del cambio de uso de suelo en los tres grupos taxonómicos. Veintinueve estudios cumplieron con el criterio de inclusión. En promedio, las plantaciones carentes de bosques ribereños albergaron 44% y 19% menos taxones que los bosques primarios y perturbados. Los taxones en los sembradíos con bosques ribereños fueron 24% menos que en el bosque primario y no difirieron significativamente del bosque perturbado. Como contraste, la composición comunitaria del riachuelo difirió entre los bosques y los sembradíos sin importar la presencia de los bosques ribereños. Atribuimos estas diferencias al uso de agroquímicos y las condiciones ambientales alteradas en las plantaciones, incluidas los cambios térmicos, condiciones hidrológicas alteradas, pérdida de microhábitats y reducción de alimentos y refugios. En general, la abundancia no difirió significativamente entre los usos de suelo porque el incremento de especies generalistas en las plantaciones contrarresta la declinación poblacional de los especialistas de bosque vulnerables. Nuestros resultados revelan un impacto significativo de la conversión de bosque a plantación sobre la biota de agua dulce, particularmente la riqueza de taxones y la composición (pero no la abundancia agregada). Aunque mantener los bosques ribereños en las plantaciones puede mitigar la pérdida de varias especies acuáticas, no puede conservar las comunidades del bosque primario. Por lo tanto, es crucial salvaguardar los bosques primarios de la expansión del aceite de palma, además de que se necesitan más investigaciones para abordar los bosques ribereños como una estrategia prometedora de mitigación en las áreas agrícolas.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Animais , Conservação dos Recursos Naturais/métodos , Florestas , Agricultura , Água Doce
19.
J Am Acad Dermatol ; 91(3): 490-498, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38697219

RESUMO

Cystic fibrosis (CF) is caused by a mutation in the Cystic fibrosis transmembrane conductance regulator (CFTR) gene, and features recurrent sinus and pulmonary infections, steatorrhea, and malnutrition. CF is associated with diverse cutaneous manifestations, including transient reactive papulotranslucent acrokeratoderma of the palms, nutrient deficiency dermatoses, and vasculitis. Rarely these are presenting symptoms of CF, prior to pulmonary or gastrointestinal sequelae. Cutaneous drug eruptions are also highly common in patients with CF (PwCF) given frequent antibiotic exposure. Finally, CFTR modulating therapy, which has revolutionized CF management, is associated with cutaneous side effects ranging from acute urticaria to toxic epidermal necrolysis. Recognition of dermatologic clinical manifestations of CF is important to appropriately care for PwCF. Dermatologists may play a significant role in the diagnosis and management of CF and associated skin complications.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Fibrose Cística , Humanos , Fibrose Cística/complicações , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Dermatopatias/etiologia , Dermatopatias/diagnóstico , Toxidermias/etiologia , Toxidermias/diagnóstico , Antibacterianos/uso terapêutico
20.
Eur J Nutr ; 63(3): 905-918, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38240773

RESUMO

PURPOSE: Vitamin A deficiency (VAD) remains a significant contributor to childhood morbidity and mortality in developing countries; therefore, the implementation of sustainable and cost-effective approaches to control VAD is of utmost pertinence. This study aims to investigate the efficacy of red palm olein (RPO)-enriched biscuit supplementation in improving vitamin A, haematological, iron, and inflammatory status among vitamin A-deficient schoolchildren. METHODS: We conducted a double-blinded, randomised controlled trial involving 651 rural primary schoolchildren (8-12 years) with VAD in Malaysia. The schoolchildren were randomised to receive either RPO-enriched biscuits (experimental group, n = 334) or palm olein-enriched biscuits (control group, n = 317) for 6-month duration. RESULTS: Significant improvements in retinol and retinol-binding protein 4 levels were observed in both groups after supplementation (P < 0.001). The improvement in retinol levels were similar across groups among subjects with confirmed VAD (P = 0.40). Among those with marginal VAD, greater improvement in retinol levels was recorded in the control group (P < 0.001) but lacked clinical significance. The levels of α- and ß-carotenes, haematological parameters (haemoglobin, packed cell volume, mean corpuscular volume and mean corpuscular haemoglobin) and iron enhanced more significantly in the experimental group (P < 0.05). The significant reduction in the prevalence of microcytic anaemia (- 21.8%) and high inflammation (- 8.1%) was only observed in the experimental group. CONCLUSION: The supplementation of RPO-enriched biscuits enhanced levels of provitamin A carotenes, iron, and erythropoiesis, and exhibited anti-inflammatory effects. Therefore, the incorporation of RPO into National Nutritional Intervention Programs may be a potential measure to improve the health status of vitamin A-deficient children, among various other interventions. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT03256123).


Assuntos
Deficiência de Vitamina A , Vitamina A , Criança , Humanos , Carotenoides , Provitaminas , Ferro , Eritropoese , Deficiência de Vitamina A/tratamento farmacológico , Deficiência de Vitamina A/epidemiologia , Suplementos Nutricionais , Estado Nutricional
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