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Dehydration-responsive element binding proteins (DREBs) are an important class of transcription factors related to plant stress tolerance. Ammopiptanthus mongolicus is an evergreen broadleaf shrub endemic to desert areas of northwest China, and it has a very high tolerance to harsh environments. In order to reveal the functions and mechanisms of the AmDREB1F gene from this species in enduring abiotic stresses, we performed subcellular localization test, expression pattern analysis, and stress tolerance evaluation of transgenic Arabidopsis harboring this gene. The protein encoded by AmDREB1F was localized in the nucleus. In laboratory-cultured A. mongolicus seedlings, the expression of AmDREB1F was induced significantly by cold and drought but very slightly by salt and heat stresses, and undetectable upon ABA treatment. In leaves of naturally growing shrubs in the wild, the expression levels of the AmDREB1F gene were much higher during the late autumn, winter and early spring than in other seasons. Moreover, the expression was abundant in roots and immature pods rather than other organs of the shrubs. Constitutive expression of AmDREB1F in Arabidopsis induced the expression of several DREB-regulated stress-responsive genes and improved the tolerance of transgenic lines to drought, high salinity and low temperature as well as oxidative stress. The constitutive expression also caused growth retardation of the transgenics, which could be eliminated by the application of gibberellin 3. Stress-inducible expression of AmDREB1F also enhanced the tolerance of transgenic Arabidopsis to all of the four stresses mentioned above, without affecting its growth and development. These results suggest that AmDREB1F gene may play positive regulatory roles in response to abiotic stresses through the ABA-independent signaling pathways.
Assuntos
Arabidopsis/metabolismo , Secas , Expressão Ectópica do Gene , Fabaceae/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Estresse Fisiológico/genéticaRESUMO
<p><b>OBJECTIVE</b>To analyze the genotype of a patient suspected for thalassemia through a series of experiments.</p><p><b>METHODS</b>Conventional methods for detecting common thalassemia mutations was used in conjunction with multiplex ligation-dependent probe amplification (MLPA) in order to determine the genotype of the patient. Corresponding primers were designed for developing a Gap-PCR system for detecting rare type mutations.</p><p><b>RESULTS</b>The patient was identified as a homozygote for Chinese Gγ(Aγδβ)-thal deletion, with clinical manifestations tending to be intermediate or severe based on the hematological characteristics. A Gap-PCR system has been developed for detecting the above mutation with accuracy and rapidity.</p><p><b>CONCLUSION</b>The Chinese Gγ(Aγδβ)-thal is prevalent in southern China, and caution should be taken to avoid misdiagnosis. The Gap-PCR system for detecting Chinese Gγ(Aγδβ)-thal is suitable for extended applications for its simplicity and rapidity.</p>
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[ ABSTRACT] AIM:To investigate the effects of sulindac on oxidative stress in autism.METHODS:With an au-tistic model induced by prenatal exposure to valproic acid ( VPA) , we detected the expression of the signaling molecules of canonical Wnt pathway in the prefrontal cortex ( PFC) and hippocampus ( HC) of autistic rats treated with sulindac.The protein expression levels of glycogen synthase kinase 3β(GSK-3β), β-catenin and 4-hydroxynonenal (4-HNE) were ob-served by Western blotting.The mRNA expression of thioredoxin(Trx)1 and Trx2 was assessed by semi-quantitative RT-PCR.RESULTS:The protein level of GSK-3βand mRNA levels of Trx1 and Trx2 were lower, whereas the protein expres-sion levels ofβ-catenin and 4-HNE were higher in VPA group than those in control group.In contrast, the protein levels of GSK-3βwere significantly higher in the animals treated with both VPA and sulindac than those in VPA group, while the lev-els ofβ-catenin and 4-HNE were decreased.CONCLUSION:Sulindac attenuates oxidative stress in the pathogenesis of au-tism, suggesting the up-regulation of the Wnt/β-catenin signaling pathway disrupts oxidative homeostasis and further facili-tates susceptibility to autism.
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[ABSTRACT]AIM:ToinvestigatetherolesofthecanonicalWntpathwayinautism.METHODS:Usinganau-tistic model induced by prenatal exposure to valproic acid ( VPA) , we detected the expression of the signaling molecules of the canonical Wnt pathway in the prefrontal cortex (PFC) and hippocampus formation (HF) of autistic rats.The expres-sion levels of glycogen synthase kinase 3β( GSK-3β) , phosphorylated GSK-3β, β-catenin and phosphorylated β-catenin were observed by Western blotting .The mRNA expression of GSK-3β, β-catenin, c-Myc and cyclin D1 was assessed by semi-quantitative RT-PCR.RESULTS:The results of Western blotting showed that inactivated GSK-3β(Ser9) phospho-rylation was significantly increased , and inhibitory β-catenin ( Ser33/37/Thr41 ) phosphorylation was obviously decreased compared with control group .The results of RT-PCR showed that the mRNA levels of β-catenin, c-Myc and cyclin D1 in-creased, and GSK-3βwas significantly enhanced in VPA-exposed rats compared with the controls .CONCLUSION: In-creased activity of canonical Wnt pathway in the PFC and HF of autistic rats may contribute to the susceptibility to autism .
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Objective To investigate the differences of connexin 43(Cx43)expression between adult and infant heart. Methods By using immunohistochemistry to observe the expression of Cx43. Results 1.The expression of Cx43 had a punclate distribution in cytoplasm and over the entire surface of the cardiocyte,and a few located at intercalated disk of atrial and ventricular myocardium in the infant heart.2.Cx43 positive granules distributed irregularly in cell side surface and cytoplasm as well as intercalated disk in adult atrium.Cx43 immunolabelling of adult ventricular myocardium was typically confined to the site of intercalated disk.3.The results of image analyzer showed that the amount of connexin43 expression was lower in the atrium than that of the ventricle in infant heart and atrium bigger than ventricle in adult heart.The expression of Cx43 was less in adult heart than that of infant heart.Conclusion The expression of Cx43 was mainly over the entire surface of the myocardium in infant heart.There were expression differences of Cx43 in human ventricular and atrial myocytes.The amount of Cx43 expression was higher in ventricle than that of atrium in infant heart and atrium bigger than ventricle in adult heart.It was less in adult heart than that of infant.It showed that the expression of Cx43 in human heart existed a developmental differences.
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Objective To research pacemaker cells outside conductive system of rat and mouse heart. Methods Paraffin and frozen serial sections (stained with HE, Masson, cholinesterase technique), and ultrastructural sections, from atrial tissue of 10 rats and 15 mice were observed by light and electron microscopy to find latent pacemaker-like cells. Results Some round or elliptical cells were scattered and irregularly detected in right and left atrial tissue of rat and mouse. Their nuclei were larger, plasma was clearer and cellular organelles were fewer than those of working myocyte. These cells were similar to pacemaker cells in sinoatrial node.Conclusion There are some pacemaker-like cells in right and left atrial tissue of rat and mouse. The finding can provide a morphological basis for ectopic beat of atrium.
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The salivary glands were exposed and isolated from the larvae of Simulium quinquestriatum and stained in carbol fuchsin, squashed between slide and coverslide. Slides were examined and photographed under microscope to measure the polytene chromosomes. Systematic analysis was made. Results indicated that the number of the polytene chromosomes of both isolates is three. The main characteristic chromosomal structures are homologized. Only the banding types of ⅡL are different.