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1.
Sensors (Basel) ; 24(6)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38544240

RESUMO

Radio frequency (RF) technology has been applied to enable advanced behavioral sensing in human-computer interaction. Due to its device-free sensing capability and wide availability on Internet of Things devices. Enabling finger gesture-based identification with high accuracy can be challenging due to low RF signal resolution and user heterogeneity. In this paper, we propose MeshID, a novel RF-based user identification scheme that enables identification through finger gestures with high accuracy. MeshID significantly improves the sensing sensitivity on RF signal interference, and hence is able to extract subtle individual biometrics through velocity distribution profiling (VDP) features from less-distinct finger motions such as drawing digits in the air. We design an efficient few-shot model retraining framework based on first component reverse module, achieving high model robustness and performance in a complex environment. We conduct comprehensive real-world experiments and the results show that MeshID achieves a user identification accuracy of 95.17% on average in three indoor environments. The results indicate that MeshID outperforms the state-of-the-art in identification performance with less cost.


Assuntos
Algoritmos , Gestos , Humanos , Reconhecimento Automatizado de Padrão/métodos , Dedos , Movimento (Física)
2.
Nat Genet ; 55(2): 178-186, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36658435

RESUMO

Precision medicine promises to transform healthcare for groups and individuals through early disease detection, refining diagnoses and tailoring treatments. Analysis of large-scale genomic-phenotypic databases is a critical enabler of precision medicine. Although Asia is home to 60% of the world's population, many Asian ancestries are under-represented in existing databases, leading to missed opportunities for new discoveries, particularly for diseases most relevant for these populations. The Singapore National Precision Medicine initiative is a whole-of-government 10-year initiative aiming to generate precision medicine data of up to one million individuals, integrating genomic, lifestyle, health, social and environmental data. Beyond technologies, routine adoption of precision medicine in clinical practice requires social, ethical, legal and regulatory barriers to be addressed. Identifying driver use cases in which precision medicine results in standardized changes to clinical workflows or improvements in population health, coupled with health economic analysis to demonstrate value-based healthcare, is a vital prerequisite for responsible health system adoption.


Assuntos
Atenção à Saúde , Medicina de Precisão , Humanos , Singapura , Medicina de Precisão/métodos , Ásia
3.
Front Oncol ; 8: 495, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30420942

RESUMO

Background: Bisphosphonates are widely prescribed for the prevention and treatment of osteoporosis. Recent epidemiological studies indicate that people with bisphosphonate use may have lower cancer risk and have improved survival. The aim of this study is to determine the association between bisphosphonate use and survival outcomes in solid cancer patients using systematic review and meta-analysis. Methods: A systematic literature search was performed using the PubMed, Embase, and Cochrane databases. Original articles published until April, 2018 were selected. The survival outcome measures assessed included overall survival (OS), cancer-specific survival (CSS) and recurrence-free survival (RFS). Pooled hazard ratio (HR) and their 95% confidence interval (95% CI) were derived using a random-effects model. Results: Out of 9,742 retrieved citations, six cohort studies and two nested case-control studies satisfying the inclusion criteria were included for analyses. Bisphosphonate use was significantly associated with improved OS (HR 0.84, 95% CI 0.76-0.93), CSS (HR 0.73, 95% CI 0.58-0.90) and RFS (HR 0.72, 95% CI 0.53-0.96). The results of subgroup analyses stratified by major study characteristics were generally consistent with the main findings. For individual cancer type, we found that bisphosphonate use was significantly associated with longer OS for patients with gastroesophageal cancer (HR 0.62, 95% CI 0.40-0.98), as well as longer CSS for patients with breast cancer (HR 0.73, 95% CI 0.55-0.95). Conclusions: Current evidence indicates that bisphosphonate use is significantly associated with improved survival for patients with solid cancer. However, the prognostic effects in specific solid tumors remains to be confirmed by further large prospective cohort studies.

4.
Adv Exp Med Biol ; 916: 147-68, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27165353

RESUMO

The past decade has witnessed a remarkable advancement of the zebrafish model in cancer research. With the rapid development of genomic tools, it is increasingly feasible to perform genome-wide analyses to identify changes associated with cancer in a wide array of model organisms. These genomic tools, particularly transcriptomic analyses using DNA microarray and RNA sequencing platforms, have now become widely used in zebrafish cancer models to uncover novel biology and common molecular pathways underlying hepatocellular carcinoma, intrahepatic cholangiocarcinoma, melanoma, embryonal rhabdomyosarcoma (ERMS), T cell acute lymphoblastic leukemia (T-ALL), Ewing's sarcoma and glioma. An important finding from these studies is the high similarity and conservation of molecular pathways that underlie cancer in complementary zebrafish models and their human counterparts. Finally, these transcriptomic tools have also proven effective in the development and the validation of specific assays for chemical compound screening. In the future, other genomic tools, such as epigenetic, proteomic and metabolomic tools will likely be incorporated into zebrafish cancer studies, further refining our understanding of cancer.


Assuntos
Modelos Animais de Doenças , Expressão Gênica , Neoplasias/genética , Transcriptoma , Animais , Peixe-Zebra
5.
PLoS One ; 10(7): e0132319, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26147004

RESUMO

Previously we have generated inducible liver tumor models by transgenic expression of Myc or xmrk (activated EGFR homolog) oncogenes in zebrafish. To investigate the interaction of the two oncogenes, we crossed the two transgenic lines and observed more severe and faster hepatocarcinogenesis in Myc/xmrk double transgenic zebrafish than either single transgenic fish. RNA-Seq analyses revealed distinct changes in many molecular pathways among the three types of liver tumors. In particular, we found dramatic alteration of cancer metabolism based on the uniquely enriched pathways in the Myc/xmrk tumors. Critical glycolytic genes including hk2, pkm and ldha were significantly up-regulated in Myc/xmrk tumors but not in either single oncogene-induced tumors, suggesting a potential Warburg effect. In RT-qPCR analyses, the specific pkm2 isoformin Warburg effect was found to be highly enriched in the Myc/xmrk tumors but not in Myc or xmrk tumors, consistent with the observations in many human cancers with Warburg effect. Moreover, the splicing factor genes (hnrnpa1, ptbp1a, ptbp1b and sfrs3b) responsible for generating the pkm isoform were also greatly up-regulated in the Myc/xmrk tumors. As Pkm2 isoform is generally inactive and causes incomplete glycolysis to favor anabolism and tumor growth, by treatment with a Pkm2-specific activator, TEPP-46, we further demonstrated that activation of Pkm2 suppressed the growth of oncogenic liver as well as proliferation of liver cells. Collectively, our Myc/xmrk zebrafish model suggests synergetic effect of EGFR and MYC in triggering Warburg effect in the HCC formation and may provide a promising in vivo model for Warburg effect.


Assuntos
Carcinoma Hepatocelular/metabolismo , Proteínas de Peixes/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Animais Geneticamente Modificados , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Proteínas de Peixes/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proteínas Proto-Oncogênicas c-myc/genética , Receptores Proteína Tirosina Quinases/genética , Peixe-Zebra
6.
Mar Biotechnol (NY) ; 17(2): 162-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25326376

RESUMO

Fgf10 is a critical growth factor in mammals for development of endodermal organs such as the liver, pancreas, lung, and gut. Due to whole genome duplication, the zebrafish has two fgf10 orthologs, fgf10a and fgf10b. While fgf10a has a role in development of the esophagus and swimbladder, we found in the present study that fgf10b had a complementary expression pattern in the liver, pancreas, and gut. Morpholino knockdown of Fgf10b further confirmed its essential role in the normal development of liver and pancreas. Thus, our data provide another example of functional partition of two duplicated othologous genes during evolution.


Assuntos
Evolução Molecular , Fator 10 de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Fígado/metabolismo , Pâncreas/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Animais , Fator 10 de Crescimento de Fibroblastos/genética , Duplicação Gênica/genética , Técnicas de Silenciamento de Genes , Técnicas Histológicas , Processamento de Imagem Assistida por Computador , Hibridização In Situ , Larva/anatomia & histologia , Fígado/embriologia , Microscopia de Fluorescência , Morfolinos , Pâncreas/embriologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas de Peixe-Zebra/genética
7.
PLoS One ; 9(3): e91179, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24633177

RESUMO

Previously three oncogene transgenic zebrafish lines with inducible expression of xmrk, kras or Myc in the liver have been generated and these transgenic lines develop oncogene-addicted liver tumors upon chemical induction. In the current study, comparative transcriptomic approaches were used to examine the correlation of the three induced transgenic liver cancers with human liver cancers. RNA profiles from the three zebrafish tumors indicated relatively small overlaps of significantly deregulated genes and biological pathways. Nevertheless, the three transgenic tumor signatures all showed significant correlation with advanced or very advanced human hepatocellular carcinoma (HCC). Interestingly, molecular signature from each oncogene-induced zebrafish liver tumor correlated with only a small subset of human HCC samples (24-29%) and there were conserved up-regulated pathways between the zebrafish and correlated human HCC subgroup. The three zebrafish liver cancer models together represented nearly half (47.2%) of human HCCs while some human HCCs showed significant correlation with more than one signature defined from the three oncogene-addicted zebrafish tumors. In contrast, commonly deregulated genes (21 up and 16 down) in the three zebrafish tumor models generally showed accordant deregulation in the majority of human HCCs, suggesting that these genes might be more consistently deregulated in a broad range of human HCCs with different molecular mechanisms and thus serve as common diagnosis markers and therapeutic targets. Thus, these transgenic zebrafish models with well-defined oncogene-induced tumors are valuable tools for molecular classification of human HCCs and for understanding of molecular drivers in hepatocarcinogenesis in each human HCC subgroup.


Assuntos
Carcinoma Hepatocelular/metabolismo , Genes ras/genética , Neoplasias Hepáticas/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Receptores Proteína Tirosina Quinases/genética , Animais , Animais Geneticamente Modificados , Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/metabolismo , Peixe-Zebra
8.
PLoS One ; 8(10): e77292, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24204792

RESUMO

TCDD is one of the most persistent environmental toxicants in biological systems and its effect through aryl hydrocarbon receptor (AhR) has been well characterized. However, the information on TCDD-induced toxicity in other molecular pathways is rather limited. To fully understand molecular toxicity of TCDD in an in vivo animal model, adult zebrafish were exposed to TCDD at 10 nM for 96 h and the livers were sampled for RNA-sequencing based transcriptomic profiling. A total of 1,058 differently expressed genes were identified based on fold-change>2 and TPM (transcripts per million) >10. Among the top 20 up-regulated genes, 10 novel responsive genes were identified and verified by RT-qPCR analysis on independent samples. Transcriptomic analysis indicated several deregulated pathways associated with cell cycle, endocrine disruptors, signal transduction and immune systems. Comparative analyses of TCDD-induced transcriptomic changes between fish and mammalian models revealed that proteomic pathway is consistently up-regulated while calcium signaling pathway and several immune-related pathways are generally down-regulated. Finally, our study also suggested that zebrafish model showed greater similarity to in vivo mammalian models than in vitro models. Our study indicated that the zebrafish is a valuable in vivo model in toxicogenomic analyses for understanding molecular toxicity of environmental toxicants relevant to human health. The expression profiles associated with TCDD could be useful for monitoring environmental dioxin and dioxin-like contamination.


Assuntos
Poluentes Ambientais/toxicidade , Fígado/efeitos dos fármacos , Dibenzodioxinas Policloradas/toxicidade , Fatores de Transcrição/genética , Transcriptoma , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Ciclo Celular/genética , Bases de Dados Genéticas , Regulação da Expressão Gênica , Humanos , Imunidade Inata/genética , Fígado/metabolismo , Masculino , Mamíferos/genética , Análise de Sequência de RNA , Transdução de Sinais
9.
Environ Sci Technol ; 47(18): 10574-82, 2013 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-23919627

RESUMO

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is frequently present in indoor dust and can be detected in human milk. In order to evaluate the effects of TDCPP on vertebrate development, zebrafish embryos/larvae were used as an animal model to examine developmental phenotypes and explore possible mechanisms of toxicity by employing microarrays and iTRAQ labeling quantitative proteomics. The results demonstrated that treatment with TDCPP (3 µM) from 0.75 h postfertilization (hpf) inhibited cell rearrangement at 4 hpf, caused delay in epiboly at 5.7 and 8.5 hpf, and led to abnormal development (e.g., short tail, reduced body size) and lethality between 14 and 45 hpf, which might be related with altered expression of genes regulating embryogenesis. Furthermore, trunk curvature was observed as the main phenotype in 96 hpf zebrafish larvae exposed to 1 or 3 µM TDCPP, possibly by changing somite formation and expression of proteins related to fast muscle and cartilage development. Collectively, our results suggest that exposure to TDCPP causes developmental toxicity in vertebrates and warrant the need for studies to evaluate the potential health risks of TDCPP to developing human embryos/infants/children, due to its frequent presence in indoor dust and potential for human exposure.


Assuntos
Retardadores de Chama/toxicidade , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Organofosfatos/toxicidade , Animais , Osso e Ossos/anormalidades , Cartilagem/anormalidades , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Retardadores de Chama/farmacocinética , Perfilação da Expressão Gênica , Músculo Esquelético/anormalidades , Análise de Sequência com Séries de Oligonucleotídeos , Organofosfatos/farmacocinética , Peixe-Zebra
10.
PLoS One ; 8(1): e53562, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23349717

RESUMO

The liver is one of the most sex-dimorphic organs in both oviparous and viviparous animals. In order to understand the molecular basis of the difference between male and female livers, high-throughput RNA-SAGE (serial analysis of gene expression) sequencing was performed for zebrafish livers of both sexes and their transcriptomes were compared. Both sexes had abundantly expressed genes involved in translation, coagulation and lipid metabolism, consistent with the general function of the liver. For sex-biased transcripts, from in addition to the high enrichment of vitellogenin transcripts in spawning female livers, which constituted nearly 80% of total mRNA, it is apparent that the female-biased genes were mostly involved in ribosome/translation, estrogen pathway, lipid transport, etc, while the male-biased genes were enriched for oxidation reduction, carbohydrate metabolism, coagulation, protein transport and localization, etc. Sexual dimorphism on xenobiotic metabolism and anti-oxidation was also noted and it is likely that retinol x receptor (RXR) and liver x receptor (LXR) play central roles in regulating the sexual differences of lipid and cholesterol metabolisms. Consistent with high ribosomal/translational activities in the female liver, female-biased genes were significantly regulated by two important transcription factors, Myc and Mycn. In contrast, Male livers showed activation of transcription factors Ppargc1b, Hnf4a, and Stat4, which regulate lipid and glucose metabolisms and various cellular activities. The transcriptomic responses to sex hormones, 17ß-estradiol (E2) or 11-keto testosterone (KT11), were also investigated in both male and female livers and we found that female livers were relatively insensitive to sex hormone disturbance, while the male livers were readily affected. E2 feminized male liver by up-regulating female-biased transcripts and down-regulating male-biased transcripts. The information obtained in this study provides comprehensive insights into the sexual dimorphism of zebrafish liver transcriptome and will facilitate further development of the zebrafish as a human liver disease model.


Assuntos
Perfilação da Expressão Gênica , Hormônios Esteroides Gonadais/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Caracteres Sexuais , Peixe-Zebra/genética , Animais , Feminino , Redes Reguladoras de Genes/efeitos dos fármacos , Humanos , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de RNA , Xenobióticos/metabolismo , Peixe-Zebra/metabolismo
11.
Dis Model Mech ; 6(2): 414-23, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23038063

RESUMO

Myc is a pleiotropic transcription factor that is involved in many cellular activities relevant to carcinogenesis, including hepatocarcinogenesis. The zebrafish has been increasingly used to model human diseases and it is particularly valuable in helping to identify common and conserved molecular mechanisms in vertebrates. Here we generated a liver tumor model in transgenic zebrafish by liver-specific expression of mouse Myc using a Tet-On system. Dosage-dependent induction of Myc expression specifically in the liver was observed in our Myc transgenic zebrafish, TO(Myc), and the elevated Myc expression caused liver hyperplasia, which progressed to hepatocellular adenoma and carcinoma with prolonged induction. Next generation sequencing-based transcriptomic analyses indicated that ribosome proteins were overwhelmingly upregulated in the Myc-induced liver tumors. Cross-species analyses showed that the zebrafish Myc model correlated well with Myc transgenic mouse models for liver cancers. The Myc-induced zebrafish liver tumors also possessed molecular signatures highly similar to human those of hepatocellular carcinoma. Finally, we found that a small Myc target gene set of 16 genes could be used to identify liver tumors due to Myc upregulation. Thus, our zebrafish model demonstrated the conserved role of Myc in promoting hepatocarcinogenesis in all vertebrate species.


Assuntos
Perfilação da Expressão Gênica , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Mamíferos/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas Experimentais/genética , Neoplasias Hepáticas Experimentais/patologia , Camundongos , Camundongos Transgênicos , Estadiamento de Neoplasias , Proteínas Proto-Oncogênicas c-myc/genética , Reprodutibilidade dos Testes , Análise de Sequência de RNA , Tetraciclina/farmacologia
12.
Dev Biol ; 359(2): 262-76, 2011 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-21925490

RESUMO

Developmental patterning and growth of the vertebrate digestive and respiratory tracts requires interactions between the epithelial endoderm and adjacent mesoderm. The esophagus is a specialized structure that connects the digestive and respiratory systems and its normal development is critical for both. Shh signaling from the epithelium regulates related aspects of mammalian and zebrafish digestive organ development and has a prominent effect on esophageal morphogenesis. The mechanisms underlying esophageal malformations, however, are poorly understood. Here, we show that zebrafish Ihha signaling from the epithelium acting in parallel, but independently of Shh, controls epithelial and mesenchymal cell proliferation and differentiation of smooth muscles and neurons in the gut and swimbladder. In zebrafish ihha mutants, the esophageal and swimbladder epithelium is dysmorphic, and expression of fgf10 in adjacent mesenchymal cells is affected. Analysis of the development of the esophagus and swimbladder in fgf10 mutant daedalus (dae) and compound dae/ihha mutants shows that the Ihha-Fgf10 regulatory interaction is realized through a signaling feedback loop between the Ihha-expressing epithelium and Fgf10-expressing mesenchyme. Disruption of this loop further affects the esophageal and swimbladder epithelium in ihha mutants, and Ihha acts in parallel to but independently of Shha in this process. These findings contribute to the understanding of epithelial-mesenchymal interactions and highlight an interaction between Hh and Fgf signaling pathways during esophagus and swimbladder development.


Assuntos
Fator 10 de Crescimento de Fibroblastos/metabolismo , Proteínas Hedgehog/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Sacos Aéreos/embriologia , Sacos Aéreos/metabolismo , Animais , Animais Geneticamente Modificados , Proliferação de Células , Embrião não Mamífero/embriologia , Embrião não Mamífero/metabolismo , Epitélio/embriologia , Epitélio/metabolismo , Esôfago/embriologia , Esôfago/metabolismo , Feminino , Fator 10 de Crescimento de Fibroblastos/genética , Trato Gastrointestinal/citologia , Trato Gastrointestinal/embriologia , Trato Gastrointestinal/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas Hedgehog/genética , Hibridização In Situ , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mesoderma/embriologia , Mesoderma/metabolismo , Microscopia Confocal , Mutação , Receptores Patched , Ligação Proteica , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
13.
PLoS One ; 6(8): e24019, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21887364

RESUMO

The fish swimbladder is a unique organ in vertebrate evolution and it functions for regulating buoyancy in most teleost species. It has long been postulated as a homolog of the tetrapod lung, but the molecular evidence is scarce. In order to understand the molecular function of swimbladder as well as its relationship with lungs in tetrapods, transcriptomic analyses of zebrafish swimbladder were carried out by RNA-seq. Gene ontology classification showed that genes in cytoskeleton and endoplasmic reticulum were enriched in the swimbladder. Further analyses depicted gene sets and pathways closely related to cytoskeleton constitution and regulation, cell adhesion, and extracellular matrix. Several prominent transcription factor genes in the swimbladder including hoxc4a, hoxc6a, hoxc8a and foxf1 were identified and their expressions in developing swimbladder during embryogenesis were confirmed. By comparison of enriched transcripts in the swimbladder with those in human and mouse lungs, we established the resemblance of transcriptome of the zebrafish swimbladder and mammalian lungs. Based on the transcriptomic data of zebrafish swimbladder, the predominant functions of swimbladder are in its epithelial and muscular tissues. Our comparative analyses also provide molecular evidence of the relatedness of the fish swimbladder and mammalian lung.


Assuntos
Sacos Aéreos/química , Pulmão/química , RNA Mensageiro/análise , Peixe-Zebra/genética , Sacos Aéreos/fisiologia , Animais , Citoesqueleto , Desenvolvimento Embrionário , Retículo Endoplasmático , Humanos , Pulmão/fisiologia , Camundongos , Peixe-Zebra/fisiologia
14.
Dev Biol ; 331(2): 222-36, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19422819

RESUMO

The swimbladder is a hydrostatic organ in fish postulated as a homolog of the tetrapod lung. While lung development has been well studied, the molecular mechanism of swimbladder development is essentially uncharacterized. In the present study, swimbladder development in zebrafish was analyzed by using several molecular markers: hb9 (epithelium), fgf10a and acta2 (mesenchyme), and anxa5 (mesothelium), as well as in vivo through enhancer trap transgenic lines Et(krt4:EGFP)(sq33-2) and Et(krt4:EGFP)(sqet3) that showed strong EGFP expression in the swimbladder epithelium and outer mesothelium respectively. We defined three phases of swimbladder development: epithelial budding between 36 and 48 hpf, growth with the formation of two additional mesodermal layers up to 4.5 dpf, and inflation of posterior and anterior chambers at 4.5 and 21 dpf respectively. Similar to those in early lung development, conserved expression of Hedgehog (Hh) genes, shha and ihha, in the epithelia, and Hh receptor genes, ptc1 and ptc2, as well as fgf10a in mesenchyme was observed. By analyzing several mutants affecting Hh signaling and Ihha morphants, we demonstrated an essential role of Hh signaling in swimbladder development. Furthermore, time-specific Hh inhibition by cyclopamine revealed different requirements of Hh signaling in the formation and organization of all three tissue layers of swimbladder.


Assuntos
Sacos Aéreos/embriologia , Proteínas Hedgehog/fisiologia , Proteínas de Peixe-Zebra/fisiologia , Peixe-Zebra/fisiologia , Sacos Aéreos/fisiologia , Animais , Antígenos de Diferenciação/metabolismo , Padronização Corporal/fisiologia , Embrião não Mamífero , Proteínas Hedgehog/genética , Mutação , Transdução de Sinais , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genética
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