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1.
J Cell Sci ; 137(1)2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38063216

RESUMO

In Chlamydomonas, the channel polycystin 2 (PKD2) is primarily present in the distal region of cilia, where it is attached to the axoneme and mastigonemes, extracellular polymers of MST1. In a smaller proximal ciliary region that lacks mastigonemes, PKD2 is more mobile. We show that the PKD2 regions are established early during ciliogenesis and increase proportionally in length as cilia elongate. In chimeric zygotes, tagged PKD2 rapidly entered the proximal region of PKD2-deficient cilia, whereas the assembly of the distal region was hindered, suggesting that axonemal binding of PKD2 requires de novo assembly of cilia. We identified the protein Small Interactor of PKD2 (SIP), a PKD2-related, single-pass transmembrane protein, as part of the PKD2-mastigoneme complex. In sip mutants, stability and proteolytic processing of PKD2 in the cell body were reduced and PKD2-mastigoneme complexes were absent from the cilia. Like the pkd2 and mst1 mutants, sip mutant cells swam with reduced velocity. Cilia of the pkd2 mutant beat with an increased frequency but were less efficient in moving the cells, suggesting a structural role for the PKD2-SIP-mastigoneme complex in increasing the effective surface of Chlamydomonas cilia.


Assuntos
Chlamydomonas , Cílios , Cílios/metabolismo , Chlamydomonas/genética , Chlamydomonas/metabolismo , Proteínas/metabolismo , Axonema/metabolismo
2.
J Cell Sci ; 136(3)2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36752106

RESUMO

Cilia are surface-exposed organelles that provide motility and sensory functions for cells, and it is widely believed that mechanosensation can be mediated through cilia. Polycystin-1 and -2 (PC-1 and PC-2, respectively) are transmembrane proteins that can localize to cilia; however, the molecular mechanisms by which polycystins contribute to mechanosensation are still controversial. Studies detail two prevailing models for the molecular roles of polycystins on cilia; one stresses the mechanosensation capabilities and the other unveils their ligand-receptor nature. The discovery that polycystins interact with mastigonemes, the 'hair-like' protrusions of flagella, is a novel finding in identifying the interactors of polycystins in cilia. While the functions of polycystins proposed by both models may coexist in cilia, it is hoped that a precise understanding of the mechanism of action of polycystins can be achieved by uncovering their distribution and interacting factors inside cilia. This will hopefully provide a satisfying answer to the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD), which is caused by mutations in PC-1 and PC-2. In this Review, we discuss the characteristics of polycystins in the context of cilia and summarize the functions of mastigonemes in unicellular ciliates. Finally, we compare flagella and molecular features of PC-2 between unicellular and multicellular organisms, with the aim of providing new insights into the ciliary roles of polycystins in general.


Assuntos
Cílios , Rim Policístico Autossômico Dominante , Humanos , Cílios/metabolismo , Canais de Cátion TRPP/genética , Rim Policístico Autossômico Dominante/genética , Mutação
3.
Proc Natl Acad Sci U S A ; 118(23)2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34074768

RESUMO

The impact of the Drosophila experimental system on studies of modern biology cannot be understated. The ability to tag endogenously expressed proteins is essential to maximize the use of this model organism. Here, we describe a method for labeling endogenous proteins with self-complementing split fluorescent proteins (split FPs) in a cell-type-specific manner in Drosophila A short fragment of an FP coding sequence is inserted into a specific genomic locus while the remainder of the FP is expressed using an available GAL4 driver line. In consequence, complementation fluorescence allows examination of protein localization in particular cells. Besides, when inserting tandem repeats of the short FP fragment at the same genomic locus, we can substantially enhance the fluorescence signal. The enhanced signal is of great value in live-cell imaging at the subcellular level. We can also accomplish a multicolor labeling system with orthogonal split FPs. However, other orthogonal split FPs do not function for in vivo imaging besides split GFP. Through protein engineering and in vivo functional studies, we report a red split FP that we can use for duplexed visualization of endogenous proteins in intricate Drosophila tissues. Using the two orthogonal split FP systems, we have simultaneously imaged proteins that reside in distinct subsynaptic compartments. Our approach allows us to study the proximity between and localization of multiple proteins endogenously expressed in essentially any cell type in Drosophila.


Assuntos
Drosophila/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Microscopia de Fluorescência/métodos , Coloração e Rotulagem/métodos , Fator 6 de Ribosilação do ADP , Animais , Animais Geneticamente Modificados , Drosophila/genética , Proteínas de Drosophila , Fluorescência , Proteínas de Fluorescência Verde/genética , Engenharia de Proteínas , Fatores de Transcrição
4.
J Cell Sci ; 134(18)2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34415027

RESUMO

Flagellar assembly depends on intraflagellar transport (IFT), a bidirectional motility of protein carriers, the IFT trains. The trains are periodic assemblies of IFT-A and IFT-B subcomplexes and the motors kinesin-2 and IFT dynein. At the tip, anterograde trains are remodeled for retrograde IFT, a process that in Chlamydomonas involves kinesin-2 release and train fragmentation. However, the degree of train disassembly at the tip remains unknown. Here, we performed two-color imaging of fluorescent protein-tagged IFT components, which indicates that IFT-A and IFT-B proteins from a given anterograde train usually return in the same set of retrograde trains. Similarly, concurrent turnaround was typical for IFT-B proteins and the IFT dynein subunit D1bLIC-GFP but severance was observed as well. Our data support a simple model of IFT turnaround, in which IFT-A, IFT-B and IFT dynein typically remain associated at the tip and segments of the anterograde trains convert directly into retrograde trains. Continuous association of IFT-A, IFT-B and IFT dynein during tip remodeling could balance protein entry and exit, preventing the build-up of IFT material in flagella.


Assuntos
Chlamydomonas , Dineínas , Transporte Biológico , Chlamydomonas/metabolismo , Cílios/metabolismo , Dineínas/genética , Dineínas/metabolismo , Flagelos/metabolismo , Transporte Proteico
5.
Neuroimage ; 251: 119015, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35189360

RESUMO

Background Neural connectome theory has been widely used in system neuroscience, and prompted our comprehension for the topological organizations of human cerebral cortex. However, how functional connectome is organized topologically in cerebellums remains unclear. Method Resting-state functional connectivity (rs-fcMRI) data were acquired from 1416 healthy adults in two independent samples. In Sample 1 (n = 976), both voxel-wise and node-wise topological properties for functional cerebellar connectome were estimated. Moreover, the network-based topological properties of cerebellum and cerebro-cerebellar topological mapping were investigated, respectively. Given the temporal natures in the neural population, a hidden Markov model (HMM) was further capitalized to uncover the dynamic pattern of cerebellar functional connectome. In order to test the robustness of our findings, we ran all of the analyses in an independent dataset (Sample 2; n = 440). Results We found that Crus I and II exhibited prominently high degree centrality (DC) for cerebellar functional connectome. Further, the cerebellar functional connectome and even the nested network-wise cerebellar connectome was found to be organized by small-world, modular and hierarchical manners significantly. Also, three intrinsic modules were found in cerebellar functional connectome, including attention/executive network, default mode network and task-positive network. In addition, the significant cerebro-cerebellar correlations for small-world organization and hierarchical architecture were found as well. By building cerebro-cerebellar topological mapping, both frontoparietal and subcortical networks were found to be overrepresented into cerebellums than cerebral cortex (3-fold). As for temporal natures, cerebellar functional connectome was observed to be highly flexible and modular, but showed high individual-specific variances in temporal dynamic pattern. Conclusion This study identified the topological architectures and temporal hierarchy of functional cerebellar connectome, and further demonstrated prominent functional cerebro-cerebellar couplings of small-world organization and hierarchical architectures.


Assuntos
Conectoma , Adulto , Atenção , Cerebelo/diagnóstico por imagem , Córtex Cerebral , Conectoma/métodos , Humanos , Imageamento por Ressonância Magnética/métodos
6.
Neuroimage ; 253: 119045, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35259525

RESUMO

Growing evidence supports a role of the neuropeptide oxytocin in promoting social cognition and prosocial behavior, possibly via modulation of the salience of social information. The effect of intranasal oxytocin administration on the salience network, however, is not well understood, including in the aging brain. To address this research gap, 42 young (22.52 ± 3.02 years; 24 in the oxytocin group) and 43 older (71.12 ± 5.25 years; 21 in the oxytocin group) participants were randomized to either self-administer intranasal oxytocin or placebo prior to resting-state functional imaging. The salience network was identified using independent component analysis (ICA). Independent t-tests showed that individuals in the oxytocin compared to the placebo group had lower within-network resting-state functional connectivity, both for left amygdala (MNI coordinates: x = -18, y = 0, z = -15; corrected p < 0.05) within a more ventral salience network and for right insula (MNI coordinates: x = 39, y = 6, z = -6; corrected p < 0.05) within a more dorsal salience network. Age moderation analysis furthermore demonstrated that the oxytocin-reduced functional connectivity between the ventral salience network and the left amygdala was only present in older participants. These findings suggest a modulatory role of exogenous oxytocin on resting-state functional connectivity within the salience network and support age-differential effects of acute intranasal oxytocin administration on this network.


Assuntos
Imageamento por Ressonância Magnética , Ocitocina , Administração Intranasal , Idoso , Envelhecimento , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Ocitocina/farmacologia
7.
BMC Plant Biol ; 22(1): 464, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36171555

RESUMO

BACKGROUND: Agarwood is a valuable Chinese medicinal herb and spice that is produced from wounded Aquilaria spp., is widely used in Southeast Asia and is highly traded on the market. The lack of highly responsive Aquilaria lines has seriously restricted agarwood yield and the development of its industry. In this article, a comparative transcriptome analysis was carried out between ordinary A. sinensis and Chi-Nan germplasm, which is a kind of A. sinensis tree with high agarwood-producing capacity in response to wounding stress, to elucidate the molecular mechanism underlying wounding stress in different A. sinensis germplasm resources and to help identify and breed high agarwood-producing strains. RESULTS: A total of 2427 and 1153 differentially expressed genes (DEGs) were detected in wounded ordinary A. sinensis and Chi-Nan germplasm compared with the control groups, respectively. KEGG enrichment analysis revealed that genes participating in starch metabolism, secondary metabolism and plant hormone signal transduction might play major roles in the early regulation of wound stress. 86 DEGs related to oxygen metabolism, JA pathway and sesquiterpene biosynthesis were identified. The majority of the expression of these genes was differentially induced between two germplasm resources under wounding stress. 13 candidate genes related to defence and sesquiterpene biosynthesis were obtained by WGCNA. Furthermore, the expression pattern of genes were verified by qRT-PCR. The candidate genes expression levels were higher in Chi-Nan germplasm than that in ordinary A. sinensis during early stage of wounding stress, which may play important roles in regulating high agarwood-producing capacity in Chi-Nan germplasm. CONCLUSIONS: Compared with A. sinensis, Chi-Nan germplasm invoked different biological processes in response to wounding stress. The genes related to defence signals and sesquiterepene biosynthesis pathway were induced to expression differentially between two germplasm resources. A total of 13 candidate genes were identified, which may correlate with high agarwood-producting capacity in Chi-Nan germplasm during the early stage of wounding stress. These genes will contribute to the development of functional molecular markers and the rapid breeding highly of responsive Aquilaria lines.


Assuntos
Sesquiterpenos , Thymelaeaceae , Perfilação da Expressão Gênica , Oxigênio/metabolismo , Melhoramento Vegetal , Reguladores de Crescimento de Plantas/metabolismo , Sesquiterpenos/metabolismo , Amido/metabolismo , Thymelaeaceae/genética , Thymelaeaceae/metabolismo
8.
Cereb Cortex ; 30(5): 2834-2853, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31845748

RESUMO

Globally, about 17% individuals are suffering from the maladaptive procrastination until now, which impacts individual's financial status, mental health, and even public policy. However, the comprehensive understanding of neuroanatomical understructure of procrastination still remains gap. 688 participants including 3 independent samples were recruited for this study. Brain morphological dynamics referred to the idiosyncrasies of both brain size and brain shape. Multilinear regression analysis was utilized to delineate brain morphological dynamics of procrastination in Sample 1. In the Sample 2, cross-validation was yielded. Finally, prediction models of machine learning were conducted in Sample 3. Procrastination had a significantly positive correlation with the gray matter volume (GMV) in the left insula, anterior cingulate gyrus (ACC), and parahippocampal gyrus (PHC) but was negatively correlated with GMV of dorsolateral prefrontal cortex (dlPFC) and gray matter density of ACC. Furthermore, procrastination was positively correlated to the cortical thickness and cortical complexity of bilateral orbital frontal cortex (OFC). In Sample 2, all the results were cross-validated highly. Predication analysis demonstrated that these brain morphological dynamic can predict procrastination with high accuracy. This study ascertained the brain morphological dynamics involving in self-control, emotion, and episodic prospection brain network for procrastination, which advanced promising aspects of the biomarkers for it.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Emoções/fisiologia , Rede Nervosa/fisiologia , Procrastinação/fisiologia , Autocontrole/psicologia , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Aprendizado de Máquina , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/diagnóstico por imagem , Adulto Jovem
9.
Proc Natl Acad Sci U S A ; 115(5): E934-E943, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29339469

RESUMO

Bardet-Biedl syndrome (BBS) is a ciliopathy resulting from defects in the BBSome, a conserved protein complex. BBSome mutations affect ciliary membrane composition, impairing cilia-based signaling. The mechanism by which the BBSome regulates ciliary membrane content remains unknown. Chlamydomonas bbs mutants lack phototaxis and accumulate phospholipase D (PLD) in the ciliary membrane. Single particle imaging revealed that PLD comigrates with BBS4 by intraflagellar transport (IFT) while IFT of PLD is abolished in bbs mutants. BBSome deficiency did not alter the rate of PLD entry into cilia. Membrane association and the N-terminal 58 residues of PLD are sufficient and necessary for BBSome-dependent transport and ciliary export. The replacement of PLD's ciliary export sequence (CES) caused PLD to accumulate in cilia of cells with intact BBSomes and IFT. The buildup of PLD inside cilia impaired phototaxis, revealing that PLD is a negative regulator of phototactic behavior. We conclude that the BBSome is a cargo adapter ensuring ciliary export of PLD on IFT trains to regulate phototaxis.


Assuntos
Síndrome de Bardet-Biedl/genética , Síndrome de Bardet-Biedl/metabolismo , Cílios/metabolismo , Mutação , Transporte Proteico/genética , Transporte Biológico , Membrana Celular/metabolismo , Chlamydomonas reinhardtii/genética , Chlamydomonas reinhardtii/fisiologia , Flagelos/metabolismo , Recuperação de Fluorescência Após Fotodegradação , Humanos , Fosfolipase D/metabolismo , Processos Fotoquímicos , Fototaxia , Domínios Proteicos , Proteínas/metabolismo , Transgenes
10.
Zhongguo Zhong Yao Za Zhi ; 45(7): 1641-1647, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32489044

RESUMO

Aquilaria sinensis is a typical inducible medicinal plant, that can produce agarwood only after it is wounded by external stimuli. Alternative oxidase(AOX) is one of the terminal oxidases of the plant mitochondrial electron transport, which plays an important role in plants' response to environmental stress. In order to reveal the physiological function of AOX gene in the process of agarwood formation from A.sinensis induced by wounding, AOX gene was cloned based on the transcriptome database and then identified by the bioinformatics analysis, and their expression pattern in different tissues and under wounding stress were detected by qRT-PCR. The results as follows. Three AOX genes were cloned from A.sinensis for the first time. They were named AsAOX1a, AsAOX1d and AsAOX2, respectively. The tissue expression shown that AsAOX1a is mainly expressed in the stem and the seed, and the AsAOX1d and AsAOX2 genes are mainly expressed in the pulp and the stem. AsAOX1a and AsAOX1d genes are highly responsive to wounding stress, and their response time was different. In addition, the expression of AsAOX1a and AsAOX2 induced by wounding are reduced by H_2O_2 treatment, but promoted by AsA treatment. The cloning, bioinformatics analysis and expression characteristics of AOX genes from A.sinensis provided basic information for further study the function of AOX genes in the development of A.sinensis, especially in the process of agarwood formation of A. sinensis induced by wounding.


Assuntos
Thymelaeaceae , Biologia Computacional , Proteínas de Plantas , Estresse Fisiológico , Transcriptoma
11.
Traffic ; 18(5): 277-286, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28248449

RESUMO

Cilia and eukaryotic flagella are threadlike cell extensions with motile and sensory functions. Their assembly requires intraflagellar transport (IFT), a bidirectional motor-driven transport of protein carriers along the axonemal microtubules. IFT moves ample amounts of structural proteins including tubulin into growing cilia likely explaining its critical role for assembly. IFT continues in non-growing cilia contributing to a variety of processes ranging from axonemal maintenance and the export of non-ciliary proteins to cell locomotion and ciliary signaling. Here, we discuss recent data on cues regulating the type, amount and timing of cargo transported by IFT. A regulation of IFT-cargo interactions is critical to establish, maintain and adjust ciliary length, protein composition and function.


Assuntos
Cílios/metabolismo , Cílios/fisiologia , Transporte Proteico/fisiologia , Proteínas/metabolismo , Animais , Flagelos/metabolismo , Flagelos/fisiologia , Humanos , Tubulina (Proteína)/metabolismo
12.
Brain Cogn ; 121: 11-16, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29309854

RESUMO

Procrastination is a pervasive phenomenon across different cultures and brings about lots of serious consequences, including performance, subjective well-being, and even public policy. However, little is known about the neural substrates of procrastination. In order to shed light upon this question, we investigated the neuroanatomical substrates of procrastination across two independent samples using voxel-based morphometry (VBM) method. The whole-brain analysis showed procrastination was positively correlated with the graymatter (GM) volume of clusters in the parahippocampal gyrus (PHG) and the orbital frontal cortex (OFC), while negatively correlated with the GM volume of clusters in the inferior frontal gyrus (IFG) and the middle frontal gyrus (MFG) in sample one (151 participants). We further conducted a verification procedure on another sample (108 participants) using region-of-interest analysis to examine the reliability of these results. Results showed procrastination can be predicted by the GM volume of the OFC and the MFG. The present findings suggest that the MFG and OFC, which are the key regions of self-control and emotion regulation, may play an important role in procrastination.


Assuntos
Substância Cinzenta/diagnóstico por imagem , Giro Para-Hipocampal/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Procrastinação , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Mapeamento Encefálico/métodos , Feminino , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/patologia , Substância Cinzenta/patologia , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Tamanho do Órgão , Giro Para-Hipocampal/patologia , Córtex Pré-Frontal/patologia , Reprodutibilidade dos Testes , Autocontrole , Adulto Jovem
13.
Curr Microbiol ; 74(4): 460-468, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28224223

RESUMO

Agarwood is broadly used in incense and medicine. Traditionally, agarwood formation is induced by wounding the trunks and branches of some species of Aquilaria spp., including A. sinensis. As recently evidenced, some fungi or their fermentation liquid may have the potential of inducing agarwood formation. The present study aimed to analyze the fungi isolated from an agarwood-producing A. sinensis tree and subsequently identify the fungi capable of promoting agarwood formation. We identified a total of 110 fungi isolates based on their morphological characteristics and rDNA ITS sequences. These isolates came from four different layers (namely the decomposing layer, agarwood layer, transition layer, and normal layer) near the agarwood formation site of the trunk. According to the experimental results, most of them belonged to Dothideomycetes (81.82%), while the others to Sordariomycetes (13.64%) or Eurotiomycetes (4.55%). Of note, 88 isolates were shown belonging to the species of Lasiodiplodia theobromae that are most frequently isolated from different layers. In addition, when the fermentation liquid of two isolates of L. theobromae (AF4 and AF12) and one isolate of Fusarium solani (AF21) was inoculated into the A. sinensis wood using the Agar-Wit technique, promoted agarwood formation was observed; however, the effect of AF21 did not keep stable in the later test, while AF4 and AF12 still functioned 1 year later. This study may lay a foundation for exploring the underlying mechanism of agarwood formation as well as fungi application in agarwood production.


Assuntos
Ascomicetos/metabolismo , Thymelaeaceae/microbiologia , Madeira/microbiologia , Ascomicetos/genética , DNA Ribossômico , Fermentação
14.
Plant Cell Environ ; 37(3): 780-94, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24028141

RESUMO

Iron-sulphur (Fe-S) cluster assembly occurs in chloroplasts, mitochondria and cytosol, involving dozens of genes in higher plants. In this study, we have identified 41 putative Fe-S cluster assembly genes in rice (Oryza sativa) genome, and the expression of all genes was verified. To investigate the role of Fe-S cluster assembly as a metabolic pathway, we applied abiotic stresses to rice seedlings and analysed Fe-S cluster assembly gene expression by qRT-PCR. Our data showed that genes for Fe-S cluster assembly in chloroplasts of leaves are particularly sensitive to heavy metal treatments, and that Fe-S cluster assembly genes in roots were up-regulated in response to iron toxicity, oxidative stress and some heavy metal assault. The effect of each stress treatment on the Fe-S cluster assembly machinery demonstrated an unexpected tissue or organelle specificity, suggesting that the physiological relevance of the Fe-S cluster assembly is more complex than thought. Furthermore, our results may reveal potential candidate genes for molecular breeding of rice.


Assuntos
Genes de Plantas/genética , Proteínas Ferro-Enxofre/genética , Família Multigênica , Oryza/genética , Oryza/fisiologia , Estresse Fisiológico/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Cloroplastos/efeitos dos fármacos , Cloroplastos/genética , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas Ferro-Enxofre/metabolismo , Metais Pesados/toxicidade , Modelos Biológicos , Oryza/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Paraquat/toxicidade , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Plântula/efeitos dos fármacos , Plântula/genética , Estresse Fisiológico/efeitos dos fármacos
15.
Cell Prolif ; : e13649, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38736355

RESUMO

Cell division is a highly regulated process essential for the accurate segregation of chromosomes. Central to this process is the assembly of a bipolar mitotic spindle, a highly dynamic microtubule (MT)-based structure responsible for chromosome movement. The nucleation and dynamics of MTs are intricately regulated by MT-binding proteins. Over the recent years, various MT-binding proteins have been reported to undergo liquid-liquid phase separation, forming either single- or multi-component condensates on MTs. Herein, we provide a comprehensive summary of the phase separation characteristics of these proteins. We underscore their critical roles in MT nucleation, spindle assembly and kinetochore-MT attachment during the cell division process. Furthermore, we discuss the current challenges and various remaining unsolved problems, highlights the ongoing research efforts aimed at a deeper understanding of the role of the phase separation process during spindle assembly and orientation. Our review aims to contribute to the collective knowledge in this area and stimulate further investigations that will enhance our comprehension of the intricate mechanisms governing cell division.

16.
Int J Clin Health Psychol ; 24(2): 100453, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38450251

RESUMO

Background: Time frees people from bereavement, but also fades childhood happiness, these dynamics can be understood through the framework of past temporal discounting (PTD), which refers to the gradual decrease in affect intensity elicited by recalling positive or negative events over time. Despite its importance, measuring PTD has been challenging, and its impact on real-life outcomes, such as mental health remains unknown. Method: Here, we employed a longitudinal tracking approach to measure PTD in healthy participants (N = 210) across eight time points. We recorded changes in affect intensity for positive and negative events and examined the impact of PTD on mental health outcomes, including general mental well-being, depression, stress sensitivity, and etc. Results: The results of Bayesian multilevel modeling indicated that the affect intensity for positive and negative events discounted over time at a gradually decelerating rate. Furthermore, we found that maintaining good mental health heavily depended on rapid PTD of negative events and slow PTD of positive events. Conclusions: These results provide a comprehensive characterization PTD and demonstrate its importance in maintaining mental health.

17.
Microsc Res Tech ; 86(10): 1333-1344, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36919819

RESUMO

Dracaena cambodiana Pierre ex Gagnep is an important plant resource for producing dragon's blood and one of most popular ornamental trees in China. For a better understanding of the physiological function of the stem, the structural characteristics and main substance histological location of the stems of D. cambodiana were studied. The structural characteristics of the different developmental stages of stems of D. cambodiana were observed and described detailly. And then a schematic diagram of the mature stem was created. Histochemical staining showed that two kinds of polysaccharides distributed in parenchymal cells. Saponins distributed mainly in ground tissue and phenolic compounds distributed mainly in the thick cell walls. An abundant of calcium oxalate raphide bundles were identified in cortex and primary tissue. Finally, the role of the above results in the taxonomy of Dracaena species and in their strong adaptability was discussed.


Assuntos
Dracaena , Saponinas , Extratos Vegetais/química , Dracaena/química , Fenóis , China , Resinas Vegetais
18.
bioRxiv ; 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37398320

RESUMO

In Chlamydomonas cilia, the ciliopathy-relevant TRP channel PKD2 is spatially compartmentalized into a distal region, in which PKD2 binds the axoneme and extracellular mastigonemes, and a smaller proximal region, in which PKD2 is more mobile and lacks mastigonemes. Here, we show that the two PKD2 regions are established early during cilia regeneration and increase in length as cilia elongate. In abnormally long cilia, only the distal region elongated whereas both regions adjusted in length during cilia shortening. In dikaryon rescue experiments, tagged PKD2 rapidly entered the proximal region of PKD2-deficient cilia whereas assembly of the distal region was hindered, suggesting that axonemal docking of PKD2 requires de novo ciliary assembly. We identified Small Interactor of PKD2 (SIP), a small PKD2-related protein, as a novel component of the PKD2-mastigoneme complex. In sip mutants, stability and proteolytic processing of PKD2 in the cell body were reduced and PKD2-mastigoneme complexes were absent from mutant cilia. Like the pkd2 and mst1 mutants, sip swims with reduced velocity. Cilia of the pkd2 mutant beat with normal frequency and bending pattern but were less efficient in moving cells supporting a passive role of the PKD2-SIP-mastigoneme complexes in increasing the effective surface of Chlamydomonas cilia.

19.
Chin Herb Med ; 15(1): 37-44, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36875439

RESUMO

Objective: Agarwood-a resinous wood produced by Aquilaria plants in response to injury or artificial induction-is a valuable medicinal and fragrance resource. Whole-Tree Agarwood-Inducing Technique (Agar-WIT) has been widely used to produce agarwood. However, the time-dependent characteristics of agarwood formation induced by Agar-WIT are yet to be clarified. To promote technologically efficient utilization and upgradation of Agar-WIT, the dynamic process and mechanism of agarwood formation were analyzed for one year. Methods: Agarwood formation percentage, barrier layer microscopic properties, extract levels, compound level, and characteristic chromatograms of agarwood were examined by referring to the Chinese Pharmacopeia (2020 version). Results: Agar-WIT could maintain a high percentage of agarwood formation over one year compared with that of healthy plants. Alcohol-soluble extract and agarotetrol levels showed fluctuating cyclic changes with peaks occurring first during the fifth and sixth months, and subsequently in the 11th month. Aquilaria trees subjected to Agar-WIT treatment for 1-12 months showed significant characteristics of a dynamic agarwood formation process. The barrier layer began to appear in the fourth month after treatment. Alcohol-soluble extractive levels in agarwood formed in the second month, and thereafter, exceeded 10.0%, and agarotetrol in agarwood produced after four months or later, exceeded 0.10%. Conclusion: According to the Chinese Pharmacopoeia, alcohol-soluble extractive levels in agarwood should not be less than 10.0% and agarotetrol level should exceed 0.10%. After four months of Agar-WIT treatment, the formed agarwood theoretically met these standards and was suitable for developed and utilization. However, the optimal harvest time was found to be the 11th month, followed by the sixth month after Agar-WIT treatment. Therefore, Agar-WIT resulted in swift agarwood formation and stable accumulation of alcohol-soluble extracts and agarotetrol. Thus, this method is efficient for large-scale cultivation of Aquilaria sinensis to produce agarwood and provide raw materials for the agarwood medicinal industry.

20.
Sci Signal ; 16(785): eade8111, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37192300

RESUMO

Bacillus cereus is a Gram-positive bacterium that mainly causes self-limiting emetic or diarrheal illness but can also cause skin infections and bacteremia. Symptoms of B. cereus ingestion depend on the production of various toxins that target the gastric and intestinal epithelia. From a screen of bacterial isolates from human stool samples that compromised intestinal barrier function in mice, we identified a strain of B. cereus that disrupted tight and adherens junctions in the intestinal epithelium. This activity was mediated by the pore-forming exotoxin alveolysin, which increased the production of the membrane-anchored protein CD59 and of cilia- and flagella-associated protein 100 (CFAP100) in intestinal epithelial cells. In vitro, CFAP100 interacted with microtubules and promoted microtubule polymerization. CFAP100 overexpression stabilized microtubules in intestinal epithelial cells, leading to disorganization of the microtubule network and perturbation of tight and adherens junctions. The disruption of cell junctions by alveolysin depended on the increase in CFAP100, which in turn depended on CD59 and the activation of PI3K-AKT signaling. These findings demonstrate that, in addition to forming membrane pores, B. cereus alveolysin can permeabilize the intestinal epithelium by disrupting epithelial cell junctions in a manner that is consistent with intestinal symptoms and may allow the bacteria to escape the intestine and cause systemic infections. Our results suggest the potential value of targeting alveolysin or CFAP100 to prevent B. cereus-associated intestinal diseases and systemic infections.


Assuntos
Bacillus cereus , Cílios , Humanos , Animais , Camundongos , Bacillus cereus/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Mucosa Intestinal , Exotoxinas/metabolismo , Flagelos
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