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1.
bioRxiv ; 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38562901

RESUMO

This study investigated the relationship between gut microbiota and neuropsychiatric disorders (NPDs), specifically anxiety disorder (ANXD) and/or major depressive disorder (MDD), as defined by DSM-IV or V criteria. The study also examined the influence of medication use, particularly antidepressants and/or anxiolytics, classified through the Anatomical Therapeutic Chemical (ATC) Classification System, on the gut microbiota. Both 16S rRNA gene amplicon sequencing and shallow shotgun sequencing were performed on DNA extracted from 666 fecal samples from the Tulsa-1000 and NeuroMAP CoBRE cohorts. The results highlight the significant influence of medication use; antidepressant use is associated with significant differences in gut microbiota beta diversity and has a larger effect size than NPD diagnosis. Next, specific microbes were associated with ANXD and MDD, highlighting their potential for non-pharmacological intervention. Finally, the study demonstrated the capability of Random Forest classifiers to predict diagnoses of NPD and medication use from microbial profiles, suggesting a promising direction for the use of gut microbiota as biomarkers for NPD. The findings suggest that future research on the gut microbiota's role in NPD and its interactions with pharmacological treatments are needed.

2.
Nanotechnology ; 35(16)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38198713

RESUMO

The global COVID-19 pandemic has led to an increase in the importance of implementing effective measures to prevent the spread of microorganisms. Consequently, there is a growing demand for antimicrobial materials, specifically antimicrobial textiles and face masks, because of the surge in diseases caused by bacteria and viruses like SARS-CoV-2. Face masks that possess built-in antibacterial properties can rapidly deactivate microorganisms, enabling reuse and reducing the incidence of illnesses. Among the numerous types of inorganic nanomaterials, copper oxide nanoparticles (CuO NPs) have been identified as cost-effective and highly efficient antimicrobial agents for inactivating microbes. Furthermore, biosurfactants have recently been recognized for their potential antimicrobial effects, in addition to inorganic nanoparticles. Therefore, this research's primary focus is synthesizing biosurfactant-mediated CuO NPs, integrating them into natural and synthetic fabrics such as cotton and polypropylene and evaluating the resulting fabrics' antimicrobial activity. Using rhamnolipid (RL) as a biosurfactant and employing a hydrothermal method with a pH range of 9-11, RL-capped CuO NPs are synthesized (RL-CuO NPs). To assess their effectiveness against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) microorganisms, the RL-CuO NPs are subjected to antibacterial testing. The RL-capped CuO NPs exhibited antimicrobial activity at much lower concentrations than the individual RL, CuO. RL-CuO NPs have shown a minimum inhibitory concentration (MIC) of 1.2 mg ml-1and minimum bactericidal concentration (MBC) of 1.6 mg ml-1forE. coliand a MIC of 0.8 mg ml-1and a MBC of 1.2 mg ml-1forS. aureus, respectively. Furthermore, the developed RL-CuO NPs are incorporated into cotton and polypropylene fabrics using a screen-printing technique. Subsequently, the antimicrobial activity of the coated fabrics is evaluated, revealing that RL-CuO NPs coated fabrics exhibited remarkable antibacterial properties against both gram-positive and gram-negative bacteria.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Nanopartículas , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Polipropilenos/farmacologia , Pandemias , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Anti-Infecciosos/farmacologia , Nanopartículas/química , Têxteis , Nanopartículas Metálicas/química , Cobre/farmacologia , Cobre/química
4.
ACS Chem Neurosci ; 14(10): 1785-1798, 2023 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-37125651

RESUMO

Tetrabutylammonium bromide (TBAB) is a widely used industrial reagent and is commonly found in our aquatic ecosystem as an industrial byproduct. In humans, the ingestion of TBAB causes severe neurological impairments and disorders such as vertigo, hallucinations, and delirium. Yet, the extent of environmental risk and TBAB toxicity to human health is poorly understood. In this study, we aim to determine the developmental toxicity of TBAB using zebrafish embryos as a model and provide novel insights into the mechanism of action of such chemicals on neurodevelopment and the overall embryonic program. Our results show that exposure to TBAB results in impaired development of the brain, inner ear, and pharyngeal skeletal elements in the zebrafish embryo. TBAB treatment resulted in aberrations in the specification of the neural crest precursors, hindbrain segmentation, and otic neurogenesis. TBAB treatment also induced a surge in apoptosis in the head, tail, and trunk regions of the developing embryo. Long-term TBAB exposure resulted in cardiac edema and craniofacial defects. Further, in silico molecular docking analysis indicated that TBAB binds to AMPA receptors and modulates neural developmental genes such as olfactomedin and acetylcholinesterase in the embryonic brain. To summarize, our study highlights the novel effects of TBAB on embryonic brain formation and segmentation, ear morphogenesis, and craniofacial skeletal development.


Assuntos
Crista Neural , Peixe-Zebra , Animais , Humanos , Peixe-Zebra/metabolismo , Crista Neural/metabolismo , Acetilcolinesterase/metabolismo , Ecossistema , Simulação de Acoplamento Molecular , Encéfalo/metabolismo , Proteínas de Peixe-Zebra/genética , Neurogênese , Regulação da Expressão Gênica no Desenvolvimento
5.
WIREs Mech Dis ; 15(4): e1603, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36754084

RESUMO

The genesis and functioning of the central nervous system are one of the most intricate and intriguing aspects of embryogenesis. The big lacuna in the field of human CNS development is the lack of accessibility of the human brain for direct observation during embryonic and fetal development. Thus, it is imperative to establish alternative animal models to gain deep mechanistic insights into neurodevelopment, establishment of neural circuitry, and its function. Neurodevelopmental events such as neural specification, differentiation, and generation of neuronal and non-neuronal cell types have been comprehensively studied using a variety of animal models and in vitro model systems derived from human cells. The experimentations on animal models have revealed novel, mechanistic insights into neurogenesis, formation of neural networks, and function. The models, thus serve as indispensable tools to understand the molecular basis of neurodevelopmental disorders (NDDs) arising from aberrations during embryonic development. Here, we review the spectrum of in vivo models such as fruitfly, zebrafish, frog, mice, and nonhuman primates to study neurogenesis and NDDs like microcephaly and Autism Spectrum Disorder. We also discuss nonconventional models such as ascidians and the recent technological advances in the field to study neurogenesis, disease mechanisms, and pathophysiology of human NDDs. This article is categorized under: Cancer > Stem Cells and Development Congenital Diseases > Stem Cells and Development Neurological Diseases > Stem Cells and Development Congenital Diseases > Genetics/Genomics/Epigenetics.


Assuntos
Transtorno do Espectro Autista , Microcefalia , Transtornos do Neurodesenvolvimento , Humanos , Animais , Camundongos , Peixe-Zebra , Neurogênese/fisiologia
6.
Int J Mol Sci ; 23(22)2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36430934

RESUMO

Renal luminal sodium transport is essential for physiological blood pressure control, and abnormalities in this process are strongly implicated in the pathogenesis of essential hypertension. Renal G protein-coupled receptors (GPCRs) are critical for the regulation of the reabsorption of essential nutrients, ions, and water from the glomerular filtrate. Recently, we showed that GPCR 37L1 (GPR37L1) is expressed on the apical membrane of renal proximal tubules (RPT) and regulates luminal sodium transport and blood pressure by modulating the function of the sodium proton exchanger 3 (NHE3). However, little is known about GPR37L1 intracellular signaling. Here, we show that GPR37L1 is localized to the nuclear membrane, in addition to the plasma membrane in human RPT cells. Furthermore, GPR37L1 signals via the PI3K/AKT/mTOR pathway to decrease the expression of DNA (cytosine-5)-methyltransferase 1 (DNMT1) and enhance NHE3 transcription. Overall, we demonstrate the direct role of a nuclear membrane GPCR in the regulation of renal sodium through epigenetic gene regulation.


Assuntos
Fosfatidilinositol 3-Quinases , Trocadores de Sódio-Hidrogênio , Humanos , Trocador 3 de Sódio-Hidrogênio/genética , Trocador 3 de Sódio-Hidrogênio/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Trocadores de Sódio-Hidrogênio/genética , Trocadores de Sódio-Hidrogênio/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Sódio/metabolismo , Epigênese Genética
7.
J Cell Biol ; 220(12)2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34709360

RESUMO

The dynein motor performs multiple functions in mitosis by engaging with a wide cargo spectrum. One way to regulate dynein's cargo-binding selectivity is through the C-terminal domain (CTD) of its light intermediate chain 1 subunit (LIC1), which binds directly with cargo adaptors. Here we show that mitotic phosphorylation of LIC1-CTD at its three cdk1 sites is required for proper mitotic progression, for dynein loading onto prometaphase kinetochores, and for spindle assembly checkpoint inactivation in human cells. Mitotic LIC1-CTD phosphorylation also engages the prolyl isomerase Pin1 predominantly to Hook2-dynein-Nde1-Lis1 complexes, but not to dynein-spindly-dynactin complexes. LIC1-CTD dephosphorylation abrogates dynein-Pin1 binding, promotes prophase centrosome-nuclear envelope detachment, and impairs metaphase chromosome congression and mitotic Golgi fragmentation, without affecting interphase membrane transport. Phosphomutation of a conserved LIC1-CTD SP site in zebrafish leads to early developmental defects. Our work reveals that LIC1-CTD phosphorylation differentially regulates distinct mitotic dynein pools and suggests the evolutionary conservation of this phosphoregulation.


Assuntos
Dineínas do Citoplasma/metabolismo , Mitose , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Subunidades Proteicas/metabolismo , Animais , Linhagem Celular Tumoral , Centrossomo/metabolismo , Complexo Dinactina/metabolismo , Evolução Molecular , Complexo de Golgi/metabolismo , Humanos , Interfase , Cinetocoros/metabolismo , Metáfase , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Mutantes/metabolismo , Membrana Nuclear/metabolismo , Fosforilação , Ligação Proteica , Ratos , Peixe-Zebra
8.
Cells Dev ; 166: 203682, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33994355

RESUMO

Homeotic genes and their genomic organization show remarkable conservation across bilaterians. Consequently, the regulatory mechanisms, which control hox gene expression, are also highly conserved. The crucial presence of conserved GA rich motifs between Hox genes has been previously observed but what factor binds to these is still unknown. Previously we have reported that the vertebrate homologue of Drosophila Trl-GAF preferentially binds to GA rich regions in Evx2-hoxd13 intergenic region of vertebrate HoxD cluster. In this study, we show that the vertebrate-GAF (v-GAF) binds at known cis-regulatory elements in the HoxD complex of zebrafish and mouse. We further used morpholino based knockdown and CRISPR-cas9 knockout technique to deplete the v-GAF in zebrafish. We checked expression of the HoxD genes and found gain of the HoxD4 gene in GAF knockout embryos. Further, we partially rescued the morphological phenotypes in GAF depleted embryos by providing GAF mRNA. Our results show that GAF binds at intergenic regions of the HoxD complex and is important for maintaining the spatial domains of HoxD4 expression during embryonic development.


Assuntos
Desenvolvimento Embrionário , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Animais , Padronização Corporal/genética , Desenvolvimento Embrionário/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores/genética , Proteínas de Peixe-Zebra/genética
9.
Bioessays ; 43(6): e2000238, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33837551

RESUMO

Embryos and microscopes share a long, remarkable history and biologists have always been intrigued to watch how embryos develop under the microscope. Here we discuss the advances in microscopy which have greatly influenced our current understanding of embryogenesis. We highlight the evolution of microscopes and the optical technologies that have been instrumental in studying various developmental processes. These imaging modalities provide mechanistic insights into the dynamic cellular and molecular events which drive lineage commitment and morphogenetic changes in the developing embryo. We begin the journey with a brief history of microscopy to study embryos. First, we review the principles and optics of light, fluorescence, confocal, and electron microscopy which have been key techniques for imaging cellular and molecular events during embryonic development. Next, we discuss recent key imaging modalities such as light-sheet microscopy, which are suitable for whole embryo imaging. Further, we highlight imaging techniques like multiphoton and super resolution microscopy for beyond light diffraction limit, high resolution imaging. Lastly, we review some of the scattering-based imaging methods and techniques used for imaging human embryos.


Assuntos
Desenvolvimento Embrionário , Microscopia , Embrião de Mamíferos , Feminino , Humanos , Gravidez
10.
mSphere ; 6(1)2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441405

RESUMO

Multidrug-resistant community-acquired infections caused by the opportunistic human pathogen Pseudomonas aeruginosa are increasingly reported in India and other locations globally. Since this organism is ubiquitous in the environment, samples such as sewage and wastewater are rich reservoirs of P. aeruginosa bacteriophages. In this study, we report the isolation and characterization of a novel P. aeruginosa N4-like lytic bacteriophage, vB_Pae_AM.P2 (AM.P2), from wastewater in Kerala, India. AM.P2 is a double-stranded DNA podovirus that efficiently lyses the model strain, PAO1, at a multiplicity of infection as low as 0.1 phage per bacterium and resistance frequency of 6.59 × 10-4 Synergy in bactericidal activity was observed between AM.P2 and subinhibitory concentrations of the antibiotic ciprofloxacin. Genome sequencing of AM.P2 revealed features similar to those of the N4-like P. aeruginosa phages LUZ7 and KPP21. As judged by two independent assay methods, spot tests and growth inhibition, AM.P2 successfully inhibited the growth of almost 30% of strains from a contemporary collection of multidrug-resistant P. aeruginosa clinical isolates from South India. Thus, AM.P2 may represent an intriguing candidate for inclusion in bacteriophage cocktails developed for various applications, including water decontamination and clinical bacteriophage therapy.IMPORTANCE In India, multidrug resistance determinants are much more abundant in community-associated bacterial pathogens due to the improper treatment of domestic and industrial effluents. In particular, a high bacterial load of the opportunistic pathogen P. aeruginosa in sewage and water bodies in India is well documented. The isolation and characterization of bacteriophages that could target emerging P. aeruginosa strains, representing possible epicenters for community-acquired infections, could serve as a useful alternative tool for various applications, such as phage therapy and environmental treatment. Continuing to supplement the repertoire of broad-spectrum bacteriophages is an essential tool in confronting this problem.


Assuntos
Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Genoma Bacteriano , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/virologia , Águas Residuárias/virologia , Antibacterianos/farmacologia , Bacteriófagos/classificação , DNA Viral/genética , Humanos , Índia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Sequenciamento Completo do Genoma
11.
Ecotoxicol Environ Saf ; 201: 110812, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32512419

RESUMO

Pesticides are widely used chemical compounds in agriculture to destroy insects, pests and weeds. In modern era, they form an indispensable part of agricultural and health practices. Globally, nearly 3 billion kg of pesticides are used every year with a budget of ~40 billion USD. This extensive usage has increased the crop yield as well as led to significant reduction in harvest losses and thereby, enhanced food availability. On the other hand, indiscriminate usage of these chemicals has led to several environmental implications and caused adverse effects on human health. Epidemiological evidences have revealed the harmful effects of pesticides exposure on various organs including liver, brain, lungs and colon. Recent investigations have shown that pesticides can also lead to fatal consequences such as cancer among individuals. These chemicals enter ecosystem, thus hampering the sensitive environmental equilibrium through bio-accumulation. Due to their non-biodegradable nature, they can persist in nature for years and are regarded as potent biohazard. Worldwide, very few surveillance methods have been considered, which can bring awareness among the individuals, therefore the present review is an attempt to delineate consequences induced by various types of pesticide exposure on the environment. Further, the prospective of biopesticides use could facilitate the increase of crop production without compromising human health.


Assuntos
Agentes de Controle Biológico/toxicidade , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/toxicidade , Praguicidas/toxicidade , Agentes de Controle Biológico/química , Produção Agrícola/métodos , Ecossistema , Exposição Ambiental/análise , Poluentes Ambientais/química , Humanos , Praguicidas/química
12.
Sci Rep ; 9(1): 16861, 2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31727925

RESUMO

The Wnt/ß-catenin pathway is one of the most conserved signaling pathways across species with essential roles in development, cell proliferation, and disease. Wnt signaling occurs at the protein level and via ß-catenin-mediated transcription of target genes. However, little is known about the underlying mechanisms regulating the expression of the key Wnt ligand Wnt3a or the modulation of its activity. Here, we provide evidence that there is significant cross-talk between the dopamine D2 receptor (D2R) and Wnt/ß-catenin signaling pathways. Our data suggest that D2R-dependent cross-talk modulates Wnt3a expression via an evolutionarily-conserved TCF/LEF site within the WNT3A promoter. Moreover, D2R signaling also modulates cell proliferation and modifies the pathology in a renal ischemia/reperfusion-injury disease model, via its effects on Wnt/ß-catenin signaling. Together, our results suggest that D2R is a transcriptional modulator of Wnt/ß-catenin signal transduction with broad implications for health and development of new therapeutics.


Assuntos
Células Epiteliais/metabolismo , Túbulos Renais Proximais/metabolismo , Receptores de Dopamina D2/genética , Traumatismo por Reperfusão/genética , Proteína Wnt3A/genética , beta Catenina/genética , Animais , Proliferação de Células , Dependovirus/genética , Dependovirus/metabolismo , Modelos Animais de Doenças , Embrião de Mamíferos , Células Epiteliais/patologia , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Túbulos Renais Proximais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Cultura Primária de Células , Regiões Promotoras Genéticas , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores de Dopamina D2/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Transdução de Sinais , Transfecção , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo
13.
Cells ; 8(11)2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31671858

RESUMO

Glycogen synthase kinase 3 (GSK3) slows myogenic differentiation and myoblast fusion partly by inhibiting the Wnt/ß-catenin signaling pathway. Lithium, a common medication for bipolar disorder, inhibits GSK3 via Mg+ competition and increased Ser21 (GSK3α) or Ser9 (GSK3ß) phosphorylation, leading to enhanced myoblast fusion and myogenic differentiation. However, previous studies demonstrating the effect of lithium on GSK3 have used concentrations up to 10 mM, which greatly exceeds concentrations measured in the serum of patients being treated for bipolar disorder (0.5-1.2 mM). Here, we determined whether a low-therapeutic (0.5 mM) dose of lithium could promote myoblast fusion and myogenic differentiation in C2C12 cells. C2C12 myotubes differentiated for three days in media containing 0.5 mM lithium chloride (LiCl) had significantly higher GSK3ß (ser9) and GSK3α (ser21) phosphorylation compared with control myotubes differentiated in the same media without LiCl (+2-2.5 fold, p < 0.05), a result associated with an increase in total ß-catenin. To further demonstrate that 0.5 mM LiCl inhibited GSK3 activity, we also developed a novel GSK3-specific activity assay. Using this enzyme-linked spectrophotometric assay, we showed that 0.5 mM LiCl-treated myotubes had significantly reduced GSK3 activity (-86%, p < 0.001). Correspondingly, 0.5 mM LiCl treated myotubes had a higher myoblast fusion index compared with control (p < 0.001) and significantly higher levels of markers of myogenesis (myogenin, +3-fold, p < 0.001) and myogenic differentiation (myosin heavy chain, +10-fold, p < 0.001). These results indicate that a low-therapeutic dose of LiCl is sufficient to promote myoblast fusion and myogenic differentiation in muscle cells, which has implications for the treatment of several myopathic conditions.


Assuntos
Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Cloreto de Lítio/farmacologia , Desenvolvimento Muscular/efeitos dos fármacos , Mioblastos/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Fusão Celular , Células Cultivadas , Relação Dose-Resposta a Droga , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Cloreto de Lítio/administração & dosagem , Camundongos , Mioblastos/citologia , Mioblastos/fisiologia , Via de Sinalização Wnt/efeitos dos fármacos
14.
Sci Rep ; 6(1): 22, 2016 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-28003657

RESUMO

Cytoplasmic dynein 1 is a multi-protein intracellular motor essential for mediating several mitotic functions, including the establishment of proper spindle orientation. The functional relevance and mechanistic distinctions between two discrete dynein subpopulations distinguished only by Light Intermediate Chain (LIC) homologues, LIC1 and LIC2 is unknown during mitosis. Here, we identify LIC2-dynein as the major mediator of proper spindle orientation and uncover its underlying molecular mechanism. Cortically localized dynein, essential for maintaining correct spindle orientation, consists majorly of LIC2-dynein, which interacts with cortical 14-3-3 ε- ζ and Par3, conserved proteins required for orienting the spindle. LIC2-dynein is also responsible for the majority of dynein-mediated asymmetric poleward transport of NuMA, helping focus microtubule minus ends. In addition, LIC2-dynein dominates in equatorially aligning chromosomes at metaphase and in regulating mitotic spindle length. Key mitotic functions of LIC2 were remarkably conserved in and essential for early embryonic divisions and development in zebrafish. Thus LIC2-dynein exclusively engages with two major cortical pathways to govern spindle orientation. Overall, we identify a novel selectivity of molecular interactions between the two LICs in mitosis as the underlying basis for their uneven distribution of labour in ensuring proper spindle orientation.


Assuntos
Dineínas do Citoplasma/metabolismo , Fuso Acromático , Animais , Células HeLa , Humanos , Análise de Sequência de DNA , Peixe-Zebra
15.
IUBMB Life ; 67(7): 575-87, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26173082

RESUMO

The unicellular metazoan zygote undergoes a series of cell divisions that are central to its development into an embryo. Differentiation of embryonic cells leads eventually to the development of a functional adult. Fate specification of pluripotent embryonic cells occurs during the early embryonic cleavage divisions in several animals. Early development is characterized by well-known stages of embryogenesis documented across animals--morulation, blastulation, and morphogenetic processes such as gastrulation, all of which contribute to differentiation and tissue specification. Despite this broad conservation, there exist clearly discernible morphological and functional differences across early embryonic stages in metazoans. Variations in the mitotic mechanisms of early embryonic cell divisions play key roles in governing these gross differences that eventually encode developmental patterns. In this review, we discuss molecular mechanisms of both karyokinesis (nuclear division) and cytokinesis (cytoplasmic separation) during early embryonic divisions. We outline the broadly conserved molecular pathways that operate in these two stages in early embryonic mitoses. In addition, we highlight mechanistic variations in these two stages across different organisms. We finally discuss outstanding questions of interest, answers to which would illuminate the role of divergent mitotic mechanisms in shaping early animal embryogenesis.


Assuntos
Segregação de Cromossomos , Embrião de Mamíferos/citologia , Embrião não Mamífero/citologia , Fuso Acromático , Animais , Diferenciação Celular , Citocinese , Drosophila/embriologia , Mitose , Ouriços-do-Mar/embriologia , Fuso Acromático/fisiologia
16.
Gene Expr Patterns ; 12(7-8): 245-53, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22634565

RESUMO

FGFs with similar sequences can play different roles depending on the model organisms examined. Determining these roles requires knowledge of spatio-temporal Fgf gene expression patterns. In this study, we report the cloning of chick Fgf5, 6 and 7, and examine their gene expression patterns by whole mount in situ hybridization. We show that Fgf5's spatio-temporally restricted expression pattern indicates a potentially novel role during inner ear development. Fgf6 and Fgf7, although belonging to different subfamilies with diverged sequences, are expressed in similar patterns within the mesoderm. Alignment of protein sequences and phylogenetic analysis demonstrate that FGF5 and FGF6 are highly conserved between chick, human, mouse and zebrafish. FGF7 is similarly conserved except for the zebrafish, which has considerably diverged.


Assuntos
Galinhas/metabolismo , Fator 5 de Crescimento de Fibroblastos/genética , Fator 6 de Crescimento de Fibroblastos/genética , Fator 7 de Crescimento de Fibroblastos/genética , Regulação da Expressão Gênica no Desenvolvimento , Sequência de Aminoácidos , Animais , Embrião de Galinha , Galinhas/genética , Clonagem Molecular , Sequência Conservada , Orelha Interna/embriologia , Orelha Interna/metabolismo , Fator 5 de Crescimento de Fibroblastos/metabolismo , Fator 6 de Crescimento de Fibroblastos/metabolismo , Fator 7 de Crescimento de Fibroblastos/metabolismo , Hibridização In Situ , Funções Verossimilhança , Dados de Sequência Molecular , Especificidade de Órgãos , Filogenia
17.
Dev Dyn ; 241(6): 1091-103, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22411638

RESUMO

The pharyngeal endoderm is hypothesized as the source of local signals that specify the identity of neural crest-derived mesenchyme in the arches. Sox9 is induced and maintained in prechondrogenic cells during condensation formation and endochondral ossification. Using explant culture, we determined that pharyngeal endoderm was sufficient, but not necessary for specifying prechondrogenic identity, as surrounding tissues including the otic vesicle can compensate for signals from the pharyngeal endoderm. Multiple Fgf genes are expressed specifically in the pharyngeal endoderm subjacent to the neural crest-derived mesenchyme. Fibroblast growth factor (FGF) signaling is both sufficient and required for specification of Sox9 expression and specification of prechondrogenic identity, as demonstrated by the addition of recombinant FGF protein or the FGF receptor inhibitor (SU5402) to explanted tissue, respectively. However, FGF signaling cannot maintain Sox9 expression or initiate the chondrogenic program as indicated by the absence of Col2a1 transcripts. Bone morphogenetic protein (BMP) 4 signaling can induce and maintain Sox9 expression in isolated mesenchyme, but only in combination with FGF signaling induce Col2a1 expression, and thus, chondrogenesis. Given the spatiotemporal expression patterns of FGFs and BMPs in the pharyngeal arches, we suggest that this may represent a general mechanism of local signals specifying prechondrogenic identity and initiation of the chondrogenic program.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Condrogênese/fisiologia , Fatores de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Mesoderma/fisiologia , Modelos Biológicos , Transdução de Sinais/fisiologia , Animais , Embrião de Galinha , Regulação da Expressão Gênica no Desenvolvimento/genética , Hibridização In Situ , Microesferas , Crista Neural/fisiologia , Fatores de Transcrição SOX9/metabolismo
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