RESUMO
The cellular and molecular mechanisms underlying neurodevelopmental conditions such as autism spectrum disorders have been studied intensively for decades. The ability to generate patient-specific induced pluripotent stem cells (iPSCs) now offers a novel strategy for modelling human diseases. Recent studies have reported the derivation of iPSCs from patients with neurological disorders. The key challenge remains the demonstration of disease-related phenotypes and the ability to model the disease. Here we report a case study with signs of neurodevelopmental disorders (NDDs) harbouring chromosomal rearrangements that were sequenced using long-insert DNA paired-end tag (DNA-PET) sequencing approach. We identified the disruption of a specific gene, GTDC1. By deriving iPSCs from this patient and differentiating them into neural progenitor cells (NPCs) and neurons we dissected the disease process at the cellular level and observed defects in both NPCs and neuronal cells. We also showed that disruption of GTDC1 expression in wild type human NPCs and neurons showed a similar phenotype as patient's iPSCs. Finally, we utilized a zebrafish model to demonstrate a role for GTDC1 in the development of the central nervous system. Our findings highlight the importance of combining sequencing technologies with the iPSC technology for NDDs modelling that could be applied for personalized medicine.
Assuntos
Transtorno do Espectro Autista/genética , Glicosiltransferases/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Neurais/metabolismo , Animais , Transtorno do Espectro Autista/metabolismo , Transtorno do Espectro Autista/patologia , Diferenciação Celular/genética , Sistema Nervoso Central/crescimento & desenvolvimento , Sistema Nervoso Central/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica no Desenvolvimento , Genoma Humano , Glicosiltransferases/biossíntese , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Células-Tronco Neurais/patologia , Neurônios/metabolismo , Neurônios/patologia , Medicina de Precisão , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimentoRESUMO
Delineating candidate genes at the chromosomal breakpoint regions in the apparently balanced chromosome rearrangements (ABCR) has been shown to be more effective with the emergence of next-generation sequencing (NGS) technologies. We employed a large-insert (7-11 kb) paired-end tag sequencing technology (DNA-PET) to systematically analyze genome of four patients harbouring cytogenetically defined ABCR with neurodevelopmental symptoms, including developmental delay (DD) and speech disorders. We characterized structural variants (SVs) specific to each individual, including those matching the chromosomal breakpoints. Refinement of these regions by Sanger sequencing resulted in the identification of five disrupted genes in three individuals: guanine nucleotide binding protein, q polypeptide (GNAQ), RNA-binding protein, fox-1 homolog (RBFOX3), unc-5 homolog D (C.elegans) (UNC5D), transmembrane protein 47 (TMEM47), and X-linked inhibitor of apoptosis (XIAP). Among them, XIAP is the causative gene for the immunodeficiency phenotype seen in the patient. The remaining genes displayed specific expression in the fetal brain and have known biologically relevant functions in brain development, suggesting putative candidate genes for neurodevelopmental phenotypes. This study demonstrates the application of NGS technologies in mapping individual gene disruptions in ABCR as a resource for deciphering candidate genes in human neurodevelopmental disorders (NDDs).
Assuntos
Pontos de Quebra do Cromossomo , Deficiências do Desenvolvimento/genética , Transtornos do Desenvolvimento da Linguagem/genética , Sequência de Bases , Inversão Cromossômica , Variações do Número de Cópias de DNA , Feminino , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Análise de Sequência de DNA , Translocação GenéticaRESUMO
The spider mite Tetranychus evansi Baker & Pritchard can cause severe damage to tomato crops. The predatory mite Phytoseiulus longipes Evans was recently reported in association with T. evansi in Uruguaiana, Rio Grande do Sul State, Brazil. The objective of the present study was to evaluate the effects of P. longipes on the population of T. evansi on tomatoes under screenhouse condition. The study consisted on four experiments, in each of which 80 potted plantlets were distributed in two plots of 40 plantlets each. Two weeks later, each plantlet of both plots was infested with eight adult females of T. evansi; one week after, four adult females of P. longipes were released onto each plant of one plot. The population levels of T. evansi and the damage caused by these mites were significantly lower (P < 0.05; linear mixed-effect model) in the plots where P. longipes had been released. The results indicate the potential of this predator as a candidate for classical biological control of T. evansi by inoculative releases on tomato plants.
Assuntos
Aracnídeos/fisiologia , Controle Biológico de Vetores/métodos , Solanum lycopersicum/parasitologia , Tetranychidae/parasitologia , Animais , Densidade DemográficaRESUMO
The spider mite Tetranychus evansi Baker & Pritchard can cause severe damage to tomato crops. The predatory mite Phytoseiulus longipes Evans was recently reported in association with T. evansi in Uruguaiana, Rio Grande do Sul State, Brazil. The objective of the present study was to evaluate the effects of P. longipes on the population of T. evansi on tomatoes under screenhouse condition. The study consisted on four experiments, in each of which 80 potted plantlets were distributed in two plots of 40 plantlets each. Two weeks later, each plantlet of both plots was infested with eight adult females of T. evansi; one week after, four adult females of P. longipes were released onto each plant of one plot. The population levels of T. evansi and the damage caused by these mites were significantly lower (P < 0.05; linear mixed-effect model) in the plots where P. longipes had been released. The results indicate the potential of this predator as a candidate for classical biological control of T. evansi by inoculative releases on tomato plants.