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1.
Plant J ; 115(6): 1647-1660, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37285314

RESUMO

Rice flowering is triggered by transcriptional reprogramming at the shoot apical meristem (SAM) mediated by florigenic proteins produced in leaves in response to changes in photoperiod. Florigens are more rapidly expressed under short days (SDs) compared to long days (LDs) and include the HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T1 (RFT1) phosphatidylethanolamine binding proteins. Hd3a and RFT1 are largely redundant at converting the SAM into an inflorescence, but whether they activate the same target genes and convey all photoperiodic information that modifies gene expression at the SAM is currently unclear. We uncoupled the contribution of Hd3a and RFT1 to transcriptome reprogramming at the SAM by RNA sequencing of dexamethasone-inducible over-expressors of single florigens and wild-type plants exposed to photoperiodic induction. Fifteen highly differentially expressed genes common to Hd3a, RFT1, and SDs were retrieved, 10 of which still uncharacterized. Detailed functional studies on some candidates revealed a role for LOC_Os04g13150 in determining tiller angle and spikelet development and the gene was renamed BROADER TILLER ANGLE 1 (BRT1). We identified a core set of genes controlled by florigen-mediated photoperiodic induction and defined the function of a novel florigen target controlling tiller angle and spikelet development.


Assuntos
Florígeno , Flores , Florígeno/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Meristema , Folhas de Planta/metabolismo
2.
Chem Biodivers ; 20(4): e202200913, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36947520

RESUMO

This work represents the first multi-scale study on Teucrium fruticans L. cultivated at the Ghirardi Botanic Garden (Lombardy, Northern Italy), combining a micromorphological and a phytochemical survey on the plant's aerial parts. Micromorphological investigations, performed by Light Microscopy, Fluorescence Microscopy and Scanning Electron Microscopy, highlighted the presence of five trichomes morphotypes, distinguished by a different distribution pattern: peltates, short-stalked and ball-like medium-stalked capitates, ubiquitous on the whole plant, medium-stalked and long-stalked capitates, exclusive to the floral whorls. Both peltates and medium-stalked capitates were recognized as the main terpene production sites. Phytochemical characterization focused on the essential oils (EOs), obtained by Clevenger-type hydrodistillation in February and April 2022 and characterized by Gas Chromatography-Mass Spectrometry (GC/MS), which resulted mainly formed by sesquiterpene hydrocarbons. The February EO profile was characterized by ß-caryophyllene (28.30 %) and germacrene D (19.16 %) as main compounds, while in April ß-myrcene was detected at high percentage (13.77 %), in addition to the previous two components (15.72 % and 11.55 %, respectively). Literature data, dealing with the biological activities of the main oil constituents, highlighted an anti-microbial, anti-inflammatory, and anti-tumor potential, due to the high content in sesquiterpenes and, particularly, of ß-caryophyllene and germacrene D.


Assuntos
Óleos Voláteis , Sesquiterpenos , Teucrium , Óleos Voláteis/química , Teucrium/química , Tricomas/química , Sesquiterpenos/química
3.
Molecules ; 27(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36500411

RESUMO

A multidisciplinary investigation on Achillea moschata Wulfen (Asteraceae) is outlined herein. This work, part of the European Interreg Italy-Switzerland B-ICE project, originated from an ethnobotanical survey performed in Chiesa in Valmalenco (Sondrio, Lombardy, Northern Italy) in 2019-2021 which highlighted this species' relevance of use in folk medicine to treat gastrointestinal diseases. In addition, this contribution included analyses of the: (a) phytochemical profile of the aqueous and methanolic extracts of the dried flower heads using LC-MS/MS; (b) morpho-anatomy and histochemistry of the vegetative and reproductive organs through Light, Fluorescence, and Scanning Electron Microscopy; (c) biological activity of the aqueous extract concerning the antioxidant and anti-inflammatory potential through cell-based in vitro models. A total of 31 compounds (5 phenolic acids, 13 flavonols, and 13 flavones) were detected, 28 of which included in both extracts. Covering and secreting trichomes were observed: the biseriate 10-celled glandular trichomes prevailing on the inflorescences represented the main sites of synthesis of the polyphenols and flavonoids detected in the extracts, along with volatile terpenoids. Finally, significant antioxidant and anti-inflammatory activities of the aqueous extract were documented, even at very low concentrations; for the first time, the in vitro tests allowed us to formulate hypotheses about the mechanism of action. This work brings an element of novelty due to the faithful reproduction of the traditional aqueous preparation and the combination of phytochemical and micromorphological research approaches.


Assuntos
Achillea , Achillea/química , Cromatografia Líquida , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Espectrometria de Massas em Tandem , Antioxidantes/farmacologia , Antioxidantes/química , Anti-Inflamatórios/farmacologia , Compostos Fitoquímicos/farmacologia
4.
Mov Disord ; 35(3): 401-408, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31724242

RESUMO

BACKGROUND: Although Huntington's disease (HD) is caused by a single dominant gene, it is clear that there are genetic modifiers that may influence the age of onset and disease progression. OBJECTIVES: We sought to investigate whether new inflammation-related genetic variants may contribute to the onset and progression of HD. METHODS: We first used postmortem brain material from patients at different stages of HD to look at the protein expression of toll-like receptor 4 (TLR4) and triggering receptor expressed on myeloid cells 2 (TREM2). We then genotyped the TREM2 R47H gene variant and 3 TLR4 single nucleotide polymorphisms in a large cohort of HD patients from the European Huntington's Disease Network REGISTRY. RESULTS: We found an increase in the number of cells expressing TREM2 and TLR4 in postmortem brain samples from patients dying with HD. We also found that the TREM2 R47H gene variant was associated with changes in cognitive decline in the large cohort of HD patients, whereas 2 of 3 TLR4 single nucleotide polymorphisms assessed were associated with changes in motor progression in this same group. CONCLUSIONS: These findings identify TREM2 and TLR4 as potential genetic modifiers for HD and suggest that inflammation influences disease progression in this condition. © 2019 International Parkinson and Movement Disorder Society.


Assuntos
Doença de Alzheimer , Doença de Huntington , Encéfalo , Humanos , Doença de Huntington/genética , Glicoproteínas de Membrana/genética , Células Mieloides , Receptores Imunológicos/genética , Receptor 4 Toll-Like/genética
5.
Mol Cell Neurosci ; 82: 46-57, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28476540

RESUMO

DNA methylation (DNAm) changes are of increasing relevance to neurodegenerative disorders, including Huntington's disease (HD). We performed genome-wide screening of possible DNAm changes occurring during striatal differentiation in human induced pluripotent stem cells derived from a HD patient (HD-hiPSCs) as cellular model. We identified 240 differentially methylated regions (DMRs) at promoters in fully differentiated HD-hiPSCs. Subsequently, we focused on the methylation differences in a subcluster of genes related to Jumonji Domain Containing 3 (JMJD3), a demethylase that epigenetically regulates neuronal differentiation and activates neuronal progenitor associated genes, which are indispensable for neuronal fate acquisition. Noticeably among these genes, WD repeat-containing protein 5 (WDR5) promoter was found hypermethylated in HD-hiPSCs, resulting in a significant down-modulation in its expression and of the encoded protein. A similar WDR5 expression decrease was seen in a small series of HD-hiPSC lines characterized by different CAG length. The decrease in WDR5 expression was particularly evident in HD-hiPSCs compared to hESCs and control-hiPSCs from healthy subjects. WDR5 is a core component of the MLL/SET1 chromatin remodeling complexes essential for H3K4me3, previously reported to play an important role in stem cells self-renewal and differentiation. These results suggest the existence of epigenetic mechanisms in HD and the identification of genes, which are able to modulate HD phenotype, is important both for biomarker discovery and therapeutic interventions.


Assuntos
Diferenciação Celular/genética , Epigênese Genética/genética , Histona-Lisina N-Metiltransferase/genética , Doença de Huntington/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Linhagem Celular , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina/genética , Humanos , Doença de Huntington/genética , Peptídeos e Proteínas de Sinalização Intracelular , Neurônios/metabolismo
6.
Plant Cell Environ ; 39(9): 1982-93, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27111837

RESUMO

Plants show a high degree of developmental plasticity in response to external cues, including day length and environmental stress. Water scarcity in particular can interfere with photoperiodic flowering, resulting in the acceleration of the switch to reproductive growth in several species, a process called drought escape. However, other strategies are possible and drought stress can also delay flowering, albeit the underlying mechanisms have never been addressed at the molecular level. We investigated these interactions in rice, a short day species in which drought stress delays flowering. A protocol that allows the synchronization of drought with the floral transition was set up to profile the transcriptome of leaves subjected to stress under distinct photoperiods. We identified clusters of genes that responded to drought differently depending on day length. Exposure to drought stress under floral-inductive photoperiods strongly reduced transcription of EARLY HEADING DATE 1 (Ehd1), HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1), primary integrators of day length signals, providing a molecular connection between stress and the photoperiodic pathway. However, phenotypic and transcriptional analyses suggested that OsGIGANTEA (OsGI) does not integrate drought and photoperiodic signals as in Arabidopsis, highlighting molecular differences between long and short day model species.


Assuntos
Secas , Flores/crescimento & desenvolvimento , Oryza/crescimento & desenvolvimento , Fotoperíodo , Proteínas de Plantas/metabolismo , Perfilação da Expressão Gênica , Oryza/metabolismo , Folhas de Planta/metabolismo , Estresse Fisiológico
7.
Int J Mol Sci ; 17(12)2016 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-27999405

RESUMO

Moringa oleifera seeds are a promising resource for food and non-food applications, due to their content of monounsaturated fatty acids with a high monounsaturated/saturated fatty acids (MUFA/SFA) ratio, sterols and tocopherols, as well as proteins rich in sulfated amino acids. The rapid growth of Moringa trees in subtropical and tropical areas, even under conditions of prolonged drought, makes this plant a reliable resource to enhance the nutritional status of local populations and, if rationalized cultivation practices are exploited, their economy, given that a biodiesel fuel could be produced from a source not in competition with human food crops. Despite the relatively diffuse use of Moringa seeds and their oil in traditional medicine, no pharmacological activity study has been conducted on humans. Some encouraging evidence, however, justifies new efforts to obtain clear and definitive information on the benefits to human health arising from seed consumption. A critical review of literature data concerning the composition of Moringa oil has set in motion a plan for future investigations. Such investigations, using the seeds and oil, will focus on cultivation conditions to improve plant production, and will study the health effects on human consumers of Moringa seeds and their oil.


Assuntos
Biocombustíveis/análise , Alimentos , Medicina Tradicional , Moringa oleifera/metabolismo , Extratos Vegetais/farmacologia , Óleos de Plantas/farmacologia , Sementes/metabolismo , Ácidos Graxos/análise , Flores , Humanos , Fitosteróis/análise , Folhas de Planta , Raízes de Plantas , Sementes/química , Tocoferóis/análise
8.
Int J Mol Sci ; 16(6): 12791-835, 2015 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-26057747

RESUMO

Moringa oleifera is an interesting plant for its use in bioactive compounds. In this manuscript, we review studies concerning the cultivation and production of moringa along with genetic diversity among different accessions and populations. Different methods of propagation, establishment and cultivation are discussed. Moringa oleifera shows diversity in many characters and extensive morphological variability, which may provide a resource for its improvement. Great genetic variability is present in the natural and cultivated accessions, but no collection of cultivated and wild accessions currently exists. A germplasm bank encompassing the genetic variability present in Moringa is needed to perform breeding programmes and develop elite varieties adapted to local conditions. Alimentary and medicinal uses of moringa are reviewed, alongside the production of biodiesel. Finally, being that the leaves are the most used part of the plant, their contents in terms of bioactive compounds and their pharmacological properties are discussed. Many studies conducted on cell lines and animals seem concordant in their support for these properties. However, there are still too few studies on humans to recommend Moringa leaves as medication in the prevention or treatment of diseases. Therefore, further studies on humans are recommended.


Assuntos
Antioxidantes/farmacologia , Hipoglicemiantes/farmacologia , Moringa oleifera/química , Extratos Vegetais/farmacologia , Antioxidantes/química , Hipoglicemiantes/química , Moringa oleifera/genética , Moringa oleifera/crescimento & desenvolvimento , Fenóis/análise , Extratos Vegetais/química , Folhas de Planta/química , Fenômenos Fisiológicos Vegetais , Vitaminas/análise
9.
Plants (Basel) ; 13(2)2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38256709

RESUMO

In this work, we studied Tanacetum vulgare, Tanacetum parthenium, and Tanacetum corymbosum (Asteraceae) cultivated at the Ghirardi Botanic Garden (Toscolano Maderno, Brescia, Northern Italy) of the University of Milan. An integrative research approach was adopted: microscopic and histochemical, with special focus on the secretory structures responsible for the productivity of secondary metabolites; phytochemical, with the analysis of the essential oil (EO) profiles from the air-dried, flowered aerial parts collected in June 2021; bio-ecological, with emphasis, based on literature data, on the ecology and biological activity of the main EO components. In all three species, two basic trichome morphotypes (flagellar non-glandular and biseriate glandular) occurred with different distribution patterns. The glandular ones produced terpenes, along with flavonoids. A high level of chemical variability in the EO compositions emerged, specifically for qualitative data. T. vulgare profile was more complex and heterogeneous than those obtained from T. parthenium and T. corymbosum, with camphor as the predominant compound, followed by farnesol and α-santalone, respectively. Finally, the obtained scientific findings were made available to the visitors of the botanic garden through new dissemination labeling that highlights the "invisible", microscopic features of the plants, from an Open Science perspective ("Botanic Garden, factories of molecules…work in progress"-Lombardy Region Project Lr. 25/2016, year 2021).

10.
Mol Phylogenet Evol ; 62(2): 736-47, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22138159

RESUMO

Wild grapes are woody climbers, found mostly in temperate regions of the northern hemisphere, comprising the genus Vitis. Despite its importance, the evolutionary history of Vitis is still contentious. Past studies have led to conflicting hypotheses about the phylogeny, speciation events, and biogeographic history of the genus. Here we investigate the evolutionary history of Vitis using data from four chloroplast spacers (trnH-psbA, trnK-rps16, trnF-nahJ, and rpl32-trnL) and the nuclear gene RPB2-I, and we explore mechanisms that could have shaped the observed distribution of current species. Maximum likelihood and Bayesian analyses provided similar results, strongly supporting the presence of two subgenera and suggesting a species clustering within subgenus Vitis that mainly mirrors the disjunction between the Old and New World. Vitis vinifera subsp. sylvestris was found to be sister to the Asian species while three major clades were found in the American species. A network approach confirmed the main geographic groups and highlighted different chloroplast haplotype patterns between Asian and American species. Molecular dating analysis provided the time boundaries to discuss our results. Our study shows wild grape diversification to be a continuous and complex process that concerned the Tertiary as well as the Quaternary, most likely involving both geographical and climatic forces. Local variations in extent and timing of these forces were discussed based on observed differences between groups. In the context of the Tertiary-Quaternary debate, we provide evidence in favor of the "continuous hypothesis" to explain present diversity. Finally, two directions for future research are highlighted: (i) was the earliest grape American or Asian? and (ii) are all modern grape species real?


Assuntos
DNA de Cloroplastos/genética , DNA Intergênico/genética , Especiação Genética , Filogenia , RNA Polimerase II/genética , Vitis/genética , Ásia , Teorema de Bayes , Evolução Biológica , Núcleo Celular/genética , Cloroplastos/genética , Haplótipos , Funções Verossimilhança , América do Norte , Filogeografia , Análise de Sequência de DNA , América do Sul , Vitis/classificação
11.
Database (Oxford) ; 20222022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35796594

RESUMO

DNA metabarcoding is a widespread approach for the molecular identification of organisms. While the associated wet-lab and data processing procedures are well established and highly efficient, the reference databases for taxonomic assignment can be implemented to improve the accuracy of identifications. Insects are among the organisms for which DNA-based identification is most commonly used; yet, a DNA-metabarcoding reference database specifically curated for their species identification using software requiring local databases is lacking. Here, we present COins, a database of 5' region cytochrome c oxidase subunit I sequences (COI-5P) of insects that includes over 532 000 representative sequences of >106 000 species specifically formatted for the QIIME2 software platform. Through a combination of automated and manually curated steps, we developed this database starting from all COI sequences available in the Barcode of Life Data System for insects, focusing on sequences that comply with several standards, including a species-level identification. COins was validated on previously published DNA-metabarcoding sequences data (bulk samples from Malaise traps) and its efficiency compared with other publicly available reference databases (not specific for insects). COins can allow an increase of up to 30% of species-level identifications and thus can represent a valuable resource for the taxonomic assignment of insects' DNA-metabarcoding data, especially when species-level identification is needed https://doi.org/10.6084/m9.figshare.19130465.v1.


Assuntos
Código de Barras de DNA Taxonômico , Numismática , Animais , DNA/genética , Código de Barras de DNA Taxonômico/métodos , Bases de Dados de Ácidos Nucleicos , Insetos/genética
12.
Elife ; 102021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34059198

RESUMO

Thrombocytopenic disorders have been treated with the Thrombopoietin-receptor agonist Eltrombopag. Patients with the same apparent form of thrombocytopenia may respond differently to the treatment. We describe a miniaturized bone marrow tissue model that provides a screening bioreactor for personalized, pre-treatment response prediction to Eltrombopag for individual patients. Using silk fibroin, a 3D bone marrow niche was developed that reproduces platelet biogenesis. Hematopoietic progenitors were isolated from a small amount of peripheral blood of patients with mutations in ANKRD26 and MYH9 genes, who had previously received Eltrombopag. The ex vivo response was strongly correlated with the in vivo platelet response. Induced Pluripotent Stem Cells (iPSCs) from one patient with mutated MYH9 differentiated into functional megakaryocytes that responded to Eltrombopag. Combining patient-derived cells and iPSCs with the 3D bone marrow model technology allows having a reproducible system for studying drug mechanisms and for individualized, pre-treatment selection of effective therapy in Inherited Thrombocytopenias.


Platelets are tiny cell fragments essential for blood to clot. They are created and released into the bloodstream by megakaryocytes, giant cells that live in the bone marrow. In certain genetic diseases, such as Inherited Thrombocytopenia, the bone marrow fails to produce enough platelets: this leaves patients extremely susceptible to bruising, bleeding, and poor clotting after an injury or surgery. Certain patients with Inherited Thrombocytopenia respond well to treatments designed to boost platelet production, but others do not. Why these differences exist could be investigated by designing new test systems that recreate the form and function of bone marrow in the laboratory. However, it is challenging to build the complex and poorly understood bone marrow environment outside of the body. Here, Di Buduo et al. have developed an artificial three-dimensional miniature organ bioreactor system that recreates the key features of bone marrow. In this system, megakaryocytes were grown from patient blood samples, and hooked up to a tissue scaffold made of silk. The cells were able to grow as if they were in their normal environment, and they could shed platelets into an artificial bloodstream. After treating megakaryocytes with drugs to stimulate platelet production, Di Buduo et al. found that the number of platelets recovered from the bioreactor could accurately predict which patients would respond to these drugs in the clinic. This new test system enables researchers to predict how a patient will respond to treatment, and to tailor therapy options to each individual. This technology could also be used to test new drugs for Inherited Thrombocytopenias and other blood-related diseases; if scaled-up, it could also, one day, generate large quantities of lab-grown blood cells for transfusion.


Assuntos
Benzoatos/farmacologia , Plaquetas/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Hidrazinas/farmacologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Megacariócitos/efeitos dos fármacos , Pirazóis/farmacologia , Receptores de Trombopoetina/agonistas , Nicho de Células-Tronco , Trombocitopenia/tratamento farmacológico , Trombopoese/efeitos dos fármacos , Adulto , Idoso , Reatores Biológicos , Plaquetas/metabolismo , Técnicas de Cultura de Células , Células Cultivadas , Feminino , Fibroínas/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Megacariócitos/metabolismo , Pessoa de Meia-Idade , Miniaturização , Mutação , Cadeias Pesadas de Miosina/genética , Receptores de Trombopoetina/metabolismo , Trombocitopenia/sangue , Trombocitopenia/genética , Adulto Jovem
13.
Evol Dev ; 12(1): 61-73, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20156283

RESUMO

Streptocarpus is a genus showing great variation in vegetative plant architecture and hence provides an attractive system to study the evolution of morphological diversity. Besides species showing an orthodox caulescent plant organization, producing leaves from a conventional shoot apical meristem (SAM), there are species whose body plan is composed of units (phyllomorphs) consisting of a petiole-like structure and a lamina that has the ability of continued growth. The first of these units is the macrocotyledon, derived from the continued growth of one of the two cotyledons by the activity of a basal meristem (BM), whereas further phyllomorphs develop from a SAM-like meristem. We carried out anatomical and morphological studies on the macrocotyledon of Streptocarpus rexii showing that the lamina has a bifacial structure, whereas the petiolode is partially unifacial. YABBY transcription factors are known to be involved in organ polarity and also promote lamina growth. We characterized the expression of SrGRAM, an ortholog of the YABBY genes GRAMINIFOLIA (GRAM) and FILAMENTOUS FLOWER (FIL), in S. rexii by in situ hybridization and RT-PCR. Gene expression pattern during embryogenesis was found to be conserved between SrGRAM and FIL from Arabidopsis. During subsequent seedling development SrGRAM expression in S. rexii was closely associated with the activity of the BM of the macrocotyledon and consecutively produced phyllomorphs, whereas it was excluded from the SAM-like meristem. Our results suggest that SrGRAM acts in intercalary growth and that an altered regulation of SrGRAM may underlay the evolution of the BM in S. rexii.


Assuntos
Genes de Plantas , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/genética , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Sequência de Bases , Evolução Biológica , Clonagem Molecular , Cotilédone/crescimento & desenvolvimento , DNA de Plantas/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Germinação/genética , Hibridização In Situ , Meristema/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Fenótipo , Filogenia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
14.
Dev Genes Evol ; 220(1-2): 25-40, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20502914

RESUMO

The mutually exclusive relationship between ARP and KNOX1 genes in the shoot apical meristem and leaf primordia in simple leaved plants such as Arabidopsis has been well characterized. Overlapping expression domains of these genes in leaf primordia have been described for many compound leaved plants such as Solanum lycopersicum and Cardamine hirsuta and are regarded as a characteristic of compound leaved plants. Here, we present several datasets illustrating the co-expression of ARP and KNOX1 genes in the shoot apical meristem, leaf primordia, and developing leaves in plants with simple leaves and simple primordia. Streptocarpus plants produce unequal cotyledons due to the continued activity of a basal meristem and produce foliar leaves termed "phyllomorphs" from the groove meristem in the acaulescent species Streptocarpus rexii and leaves from a shoot apical meristem in the caulescent Streptocarpus glandulosissimus. We demonstrate that the simple leaves in both species possess a greatly extended basal meristematic activity that persists over most of the leaf's growth. The area of basal meristem activity coincides with the co-expression domain of ARP and KNOX1 genes. We suggest that the co-expression of ARP and KNOX1 genes is not exclusive to compound leaved plants but is associated with foci of meristematic activity in leaves.


Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/genética , Meristema/genética , Folhas de Planta/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Cardamine/genética , Cardamine/crescimento & desenvolvimento , Genes de Plantas , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Dados de Sequência Molecular , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
15.
Planta ; 230(3): 529-42, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19526368

RESUMO

Acaulescent species of Streptocarpus Lindl. show unusual patterns of growth, characterized by anisocotyly (i.e. the unequal growth of cotyledons after germination) and lack of a conventional embryonic shoot apical meristem (SAM). A SAM-like structure appears during post-embryonic development on the axis of the continuously growing cotyledon. Since we have shown previously that KNOX genes are involved in this unusual morphology of Streptocarpus rexii, here we investigated the expression pattern of WUSCHEL (WUS), which is also required for the indeterminacy of the SAM, but is expressed independently from KNOX in Arabidopsis thaliana. In A. thaliana WUSCHEL is involved in the maintenance of the stem cell fate in the organizing centre. The expression pattern of the WUS ortholog in S. rexii (SrWUS) strongly deviates from that of the model plant, suggesting a fundamentally different spatial and temporal regulation of signalling involved in meristem initiation and maintenance. In S. rexii, exogenous application of growth regulators, i.e. gibberellin (GA(3)), cytokinin (CK) and a gibberellin biosynthesis inhibitor (PAC), prevents anisocotyly and relocates meristematic cells to a position of conventional SAMs; this coincides with a re-localization of the two main pathways controlling meristem formation, the SrWUS and the KNOX pathways. Our results suggest that the establishment of a hormone imbalance in the seedlings is the basis of anisocotyly, causing a lateral dominance of the macrocotyledon over the microcotyledon. The peculiar morphogenetic program in S. rexii is linked to this delicate hormone balance and is the result of crosstalk between endogenous hormones and regulatory genes.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Homeodomínio/genética , Magnoliopsida/genética , Sequência de Bases , Primers do DNA , Genes Dominantes , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Plant Reprod ; 32(3): 323-330, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31115664

RESUMO

KEY MESSAGE: The developmental morphology of male and female kiwifruit flowers is tracked to delimit a framework of events to aid the study of divergence in floral gene expression. The transition from hermaphrodite to unisexual development of kiwifruit (Actinidia chinensis Planch) flowers has been reported previously, but differences in gene expression controlling sexual development for this species have not been associated with the major developmental changes occurring within pistils. We investigated the key stages in male and female flower development to define the point at which meristematic activities diverge in the two sexes. A combination of scanning electron microscopy and light microscopy was used to investigate pistil development from the earliest stages. We identified seven distinct stages characterized by differences in ovary size and shape, macrosporogenesis, ovule primordium development, anther locule lengthening, microspore wall thickening, and pollen degeneration. Sex differences were evident from the initial stage of development, with a laterally compacted gynoecium in male flowers. However, the key developmental stage, at which tissue differentiation clearly deviated between the two sexes, was stage 3, when flowers were 3.5 to 4.5 mm in length at approximately 10 d from initiation of stamen development. At this stage, male flowers lacked evident carpel meristem development as denoted by a lack of ovule primordium formation. Pollen degeneration in female flowers, probably driven by programmed cell death, occurred at the late stage 6, while the final stage 7 was represented by pollen release. As the seven developmental stages are associated with specific morphological differences, including flower size, the scheme suggested here can provide the required framework for the future study of gene expression during the regulation of flower development in this crop species.


Assuntos
Actinidia/crescimento & desenvolvimento , Flores/crescimento & desenvolvimento , Actinidia/genética , Actinidia/ultraestrutura , Flores/genética , Flores/ultraestrutura , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/ultraestrutura , Microscopia Eletrônica de Varredura , Óvulo Vegetal/genética , Óvulo Vegetal/crescimento & desenvolvimento , Óvulo Vegetal/ultraestrutura , Pólen/genética , Pólen/crescimento & desenvolvimento , Pólen/ultraestrutura , Reprodução
17.
Stem Cell Res ; 31: 102-112, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30071393

RESUMO

The successful exploitation of human pluripotent stem cells (hPSCs) for research, translational or commercial reasons requires the implementation of a simple and efficient cryopreservation method. Cryopreservation is usually performed with dimethylsulphoxide (DMSO), in addition to animal proteins. However, even at sub-toxic levels, DMSO diminishes the pluripotency capacity of hPSCs and affects their epigenetic system by acting on the three DNA methyltransferases (Dnmts) and histone modification enzymes. Our study aimed to test trehalose-based cryosolutions containing ethylene glycol (EG) or glycerol (GLY) on hESCs RC17, hiPSCs CTR2#6 and long-term neuroepithelial-like stem cells (lt-NES) AF22. Here, we demostrate the effectiveness of these cryosolutions in hPSCs by showing an acceptable rate of cell viability and high stability compared to standard 10% DMSO freezing medium (CS10). All cell lines retained their morphology, self renewal potential and pluripotency, and none of the cryosolutions affected their differentiation potential. Genotoxicity varied among different stem cells types, while trehalose-based cryopreservation did not sensibly alter the homeostasis of endoplasmic reticulum (ER). This study provides evidence that pluripotent and neural stem cells stored in trehalose alone or with other cryoprotectants (CPAs) maintain their functional properties, indicating their potential use in cell therapies if produced in good manufacturing practice (GMP) facility.


Assuntos
Criopreservação/métodos , Células-Tronco Pluripotentes/metabolismo , Trealose/metabolismo , Humanos
18.
Stem Cells Dev ; 27(4): 287-295, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29239282

RESUMO

Wolfram syndrome (WFS) is a rare autosomal premature aging syndrome that shows signs of diabetes mellitus, optic atrophy, and deafness in addition to central nervous system and endocrine complications. The frequent form of WFS type 1 (WFS1) harbors causative mutations in the WFS1 gene, whereas the rare form or WFS type 2 (WFS2) involves CISD2. Mutations in these two genes are recognized by a subset of variable clinical symptoms and a set of overlapping features. In this study, we report on the generation of stable human-induced pluripotent stem cells (hiPSCs) derived from primary fibroblasts of a previously reported Italian family with CISD2 mutation (c.103 + 1G>A), occurring in the consensus intron 1 splicing site in two sisters, deleting the first exon of the transcript. The generated hiPSCs provide a cell model system to study the mutation's role in the multisystemic clinical disorders previously described and test eventual drug effects on the specific and associated clinical phenotype.


Assuntos
Senilidade Prematura/genética , Perda Auditiva Neurossensorial/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Proteínas de Membrana/genética , Doenças Mitocondriais/genética , Mutação , Atrofia Óptica/genética , Senilidade Prematura/patologia , Proliferação de Células/genética , Células Cultivadas , Saúde da Família , Feminino , Fibroblastos/metabolismo , Perda Auditiva Neurossensorial/patologia , Humanos , Íntrons/genética , Masculino , Doenças Mitocondriais/patologia , Atrofia Óptica/patologia , Sítios de Splice de RNA/genética , Irmãos
19.
J Food Prot ; 80(4): 626-631, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28291386

RESUMO

Subsistence farming and poor storage facilities favor toxigenic fungal contamination and mycotoxin accumulation in staple foods from tropical countries such as Haiti. The present preliminary study was designed to evaluate the occurrence of toxigenic fungi in Haitian foodstuffs to define the mycotoxin risk associated with Haitian crops. The objectives of this research were to determine the distribution of toxigenic fungi in the Haitian crops maize, moringa, and peanut seeds and to screen Aspergillus section Flavi (ASF) isolates for production of aflatoxins B1 and G1 in vitro. Maize, moringa, and peanut samples were contaminated by potential toxigenic fungal taxa, mainly ASF and Fusarium spp. The isolation frequency of Aspergillus spp. and Fusarium spp. was influenced by locality and thus by farming systems, storage systems, and weather conditions. Particularly for ASF in peanut and maize samples, isolation frequencies were directly related to the growing season length. The present study represents the first report of contamination by toxigenic fungi and aflatoxin in moringa seeds, posing concerns about the safety of these seeds, which people in Haiti commonly consume. Most (80%) of the Haitian ASF strains were capable of producing aflatoxins, indicating that Haitian conditions clearly favor the colonization of toxigenic ASF strains over atoxigenic strains. ASF strains producing both aflatoxins B1 and G1 were found. Understanding the distribution of toxigenic ASF in Haitian crops and foodstuffs is important for determining accurate toxicological risks because the toxic profile of ASF is species specific. The occurrence of toxigenic fungi and the profiles of the ASF found in various crops highlight the need to prevent formation of aflatoxins in Haitian crops. This study provides relevant preliminary baseline data for guiding the development of legislation regulating the quality and safety of crops in this low-income country.


Assuntos
Aflatoxinas , Contaminação de Alimentos , Aspergillus/isolamento & purificação , Aspergillus flavus , Fungos , Haiti
20.
Biopreserv Biobank ; 15(4): 384-392, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28388226

RESUMO

Human induced pluripotent stem cell (hiPSC) biobanks are invaluable resources for basic and clinical research, since they provide a sustainable supply of accessible cell lines that meet high quality and safety standards. hiPSCs are particularly useful for understanding disease mechanisms, creating cell models for drug development, and generating novel clinical therapies. For clinical applications and drug discovery, it is fundamental that the acquired pluripotent cell lines never touch animal-derived products nor xenogeneic reagents (Good Manufacturing Practice-grade); whereas for research grade, it is sufficient to operate under Good Laboratory Practice conditions. However, regardless of the end use, it is important that every step in the whole process, starting from the original cells throughout expansion and manipulation, must be performed and recorded rigorously. Here, we describe our biobanking management system that is applied specifically to human pluripotent stem cells.


Assuntos
Bancos de Espécimes Biológicos/normas , Células-Tronco Pluripotentes Induzidas , Pesquisa/normas , Manejo de Espécimes/normas , Humanos , Manejo de Espécimes/tendências
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