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991.
Surya Kant David Burch Pieter Badenhorst Rajasekaran Palanisamy John Mason German Spangenberg 《PloS one》2015,10(1)
Delay of leaf senescence through genetic modification can potentially improve crop yield, through maintenance of photosynthetically active leaves for a longer period. Plant growth hormones such as cytokinin regulate and delay leaf senescence. Here, the structural gene (IPT) encoding the cytokinin biosynthetic enzyme isopentenyltransferase was fused to a functionally active fragment of the AtMYB32 promoter and was transformed into canola plants. Expression of the AtMYB32xs::IPT gene cassette delayed the leaf senescence in transgenic plants grown under controlled environment conditions and field experiments conducted for a single season at two geographic locations. The transgenic canola plants retained higher chlorophyll levels for an extended period and produced significantly higher seed yield with similar growth and phenology compared to wild type and null control plants under rainfed and irrigated treatments. The yield increase in transgenic plants was in the range of 16% to 23% and 7% to 16% under rainfed and irrigated conditions, respectively, compared to control plants. Most of the seed quality parameters in transgenic plants were similar, and with elevated oleic acid content in all transgenic lines and higher oil content and lower glucosinolate content in one specific transgenic line as compared to control plants. The results suggest that by delaying leaf senescence using the AtMYB32xs::IPT technology, productivity in crop plants can be improved under water stress and well-watered conditions. 相似文献
992.
Anand Kant Das Rucha Pandit Sudipta Maiti 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2015,370(1672)
Certain neurodegenerative diseases are thought to be initiated by the aggregation of amyloidogenic proteins. However, the mechanism underlying toxicity remains obscure. Most of the suggested mechanisms are generic in nature and do not directly explain the neuron-type specific lesions observed in many of these diseases. Some recent reports suggest that the toxic aggregates impair the synaptic vesicular machinery. This may lead to an understanding of the neuron-type specificity observed in these diseases. A disruption of the vesicular machinery can also be deleterious for extra-synaptic, especially somatic, neurotransmission (common in serotonergic and dopaminergic systems which are specifically affected in Alzheimer''s disease (AD) and Parkinson''s disease (PD), respectively), though this relationship has remained unexplored. In this review, we discuss amyloid-induced damage to the neurotransmitter vesicular machinery, with an eye on the possible implications for somatic exocytosis. We argue that the larger size of the system, and the availability of multi-photon microscopy techniques for directly visualizing monoamines, make the somatic exocytosis machinery a more tractable model for understanding the effect of amyloids on all types of vesicular neurotransmission. Indeed, exploring this neglected connection may not just be important, it may be a more fruitful route for understanding AD and PD. 相似文献
993.
Febe van?Maldegem Sarah Maslen Christopher M. Johnson Anita Chandra Karuna Ganesh Mark Skehel Cristina Rada 《Nucleic acids research》2015,43(14):7058-7069
In order to catalyse the splicing of messenger RNA, multiple proteins and RNA components associate and dissociate in a dynamic highly choreographed process. The Prp19 complex is a conserved essential part of the splicing machinery thought to facilitate the conformational changes the spliceosome undergoes during catalysis. Dynamic protein interactions often involve highly disordered regions that are difficult to study by structural methods. Using amine crosslinking and hydrogen–deuterium exchange coupled to mass spectrometry, we describe the architecture of the Prp19 sub-complex that contains CTNNBL1. Deficiency in CTNNBL1 leads to delayed initiation of cell division and embryonic lethality. Here we show that in vitro CTNNBL1 enhances the association of CWC15 and CDC5L, both core Prp19 complex proteins and identify an overlap in the region of CDC5L that binds either CTNNBL1 or CWC15 suggesting the two proteins might exchange places in the complex. Furthermore, in vivo, CTNNBL1 is required to maintain normal levels of the Prp19 complex and to facilitate the interaction of CWC15 with CDC5L. Our results identify a chaperone function for CTNNBL1 within the essential Prp19 complex, a function required to maintain the integrity of the complex and to support efficient splicing. 相似文献
994.
Sequence‐tagged high‐density genetic maps of Zoysia japonica provide insights into genome evolution in Chloridoideae
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Fangfang Wang Ratnesh Singh Anthony D. Genovesi Ching Man Wai Xiaoen Huang Ambika Chandra Qingyi Yu 《The Plant journal : for cell and molecular biology》2015,82(5):744-757
Zoysiagrass (Zoysia spp.), belonging to the genus Zoysia in the subfamily Chloridoideae, is widely used in domestic lawns, sports fields and as forage. We constructed high‐density genetic maps of Zoysia japonica using a restriction site‐associated DNA sequencing (RAD‐Seq) approach and an F1 mapping population derived from a cross between ‘Carrizo’ and ‘El Toro’. Two linkage maps were constructed, one for each of the parents. A map consisting of 2408 RAD markers distributed on 21 linkage groups was constructed for ‘Carrizo’. Another map with 1230 RAD markers mapped on 20 linkage groups was constructed for ‘El Toro’. The average distance between adjacent markers of the two maps was at 0.56 and 1.4 cM, respectively. Comparative genomics analysis was carried out among zoysiagrass, rice and sorghum genomes and a highly conserved collinearity in the gene order was observed among the three genomes. Chromosome collinearity was disrupted at centromeric regions for each chromosome pair between zoysiagrass and sorghum genomes. However, no obvious synteny gaps were observed across the centromeric regions between zoysiagrass and rice genomes. Two homologous chromosomes for each of the 10 sorghum chromosomes were found in the zoysiagrass genome, indicating an allotetraploid origin for zoysiagrass. The reduction of the basic chromosome number from 12 to 10 in chloridoids and panicoids took place via independent single‐step nested chromosome fusion events after the two subfamilies diverged from a common ancestor. The genetic maps will assist in genome sequence assembly, targeted gene isolation and comparative genomic analyses among grasses. 相似文献
995.
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997.
Tatyana N. Zhebentyayeva Shenghua Fan Anirudh Chandra Douglas G. Bielenberg Gregory L. Reighard William R. Okie Albert G. Abbott 《Tree Genetics & Genomes》2014,10(1):35-51
Chilling requirement (CR) for floral bud dormancy release is one of the major limiting factors for geographical adaptation of fruiting trees. Using a whole genome sequencing approach (Illumina platform), we explored polymorphism underlying phenotypic differences among individuals in a peach F2 cross segregating for chilling requirement and bloom date. Allelic configuration of individuals, which represented phenotypic extremes in the cross (300 vs. 1,100 chill hours) allowed reconstruction of low- and high-chill haplotypes within three most significant quantitative trait locus (QTL) intervals on the Prunus G1, G4, and G7. We detected single nucleotide polymorphic sites (SNPs), small deletions and insertions (DIPs), and large structural variants (SVs) associated with low-chill haplotypes and created a prioritized list of candidate genes based on functionally characterized homologs from Arabidopsis thaliana. Two dormancy associated genes PpeDAM5 and PpeDAM6 are the strongest candidate genes for the major QTL signal at the lower end of G1. Also, key functional genes involved in the Polycomb repressive mechanism, cell cycle progression, and hormone regulation were evident as strong candidate genes underlying QTL intervals in this peach cross. 相似文献
998.
Harish Chandra Pal Samriti Sharma Leah Ray Strickland Santosh K. Katiyar Mary E. Ballestas Mohammad Athar Craig A. Elmets Farrukh Afaq 《PloS one》2014,9(1)
Malignant melanoma is responsible for approximately 75% of skin cancer-related deaths. BRAF plays an important role in regulating the mitogen-activated protein kinase (MAPK) signaling cascade in melanoma with activating mutations in the serine/threonine kinase BRAF occurring in 60–70% of malignant melanomas. The BRAF-MEK-ERK (MAPK) pathway is a key regulator of melanoma cell invasion. In addition, activation of NFκB via the MAPK pathway is regulated through MEK-induced activation of IKK. These pathways are potential targets for prevention and treatment of melanoma. In this study, we investigated the effect of fisetin, a phytochemical present in fruits and vegetables, on melanoma cell invasion and epithelial-mesenchymal transition, and delineated the underlying molecular mechanism. Treatment of multiple human malignant melanoma cell lines with fisetin (5–20 µM) resulted in inhibition of cell invasion. BRAF mutated melanoma cells were more sensitive to fisetin treatment, and this was associated with a decrease in the phosphorylation of MEK1/2 and ERK1/2. In addition, fisetin inhibited the activation of IKK leading to a reduction in the activation of the NFκB signaling pathway. Treatment of cells with an inhibitor of MEK1/2 (PD98059) or of NFκB (caffeic acid phenethyl ester) also reduced melanoma cell invasion. Furthermore, treatment of fisetin promoted mesenchymal to epithelial transition in melanoma cells, which was associated with a decrease in mesenchymal markers (N-cadherin, vimentin, snail and fibronectin) and an increase in epithelial markers (E-cadherin and desmoglein). Employing three dimensional skin equivalents consisting of A375 cells admixed with normal human keratinocytes embedded onto a collagen-constricted fibroblast matrix, we found that treatment of fisetin reduced the invasive potential of melanoma cells into the dermis and increased the expression of E-cadherin with a concomitant decrease in vimentin. These results indicate that fisetin inhibits melanoma cell invasion through promotion of mesenchymal to epithelial transition and by targeting MAPK and NFκB signaling pathways. 相似文献
999.
Shatakshi Srivastava Raja Roy Santosh Kumar Hari Om Gupta Devendra Singh Jitendra Kumar Kushwaha Abhijit Chandra Abhinav Arun Sonkar 《Metabolomics : Official journal of the Metabolomic Society》2013,9(6):1181-1191
The paucity of biomarkers for malignant obstructive jaundice results in formidable morbidity and mortality rates. Therefore, alternative diagnostic measures are required for improved clinical interpretation and better peri-operative management of patients. In the present study, 1H NMR-based metabolomic approach has been applied to investigate serum and bile based metabolic biomarkers in benign and malignant causes of obstructive jaundice (OBJ). Serum and bile specimens from benign OBJ patients (n = 28), malignant OBJ patients (n = 36) and serum of healthy controls (n = 57) were analysed by 1H NMR spectroscopy. Quantitation of eight serum metabolites (isobutyrate, lactate, alanine, acetone, glutamine, creatine, threonine and 1-methylhistidine) was carried out. A newer and rapid single step NMR based semi-quantitative ratio analysis of serum total cholesterol (tCho), cholesterol (Chol) and cholesterol ester (CE) were performed in deuterated dimethyl sulfoxide-d6. In bile, total bile acids, cholesterol, phosphatidylcholine, glycerophosphatidylcholine and urea were quantified. The effect of benign and malignant OBJ on small metabolites and lipids were statistically analysed by Mann–Whitney U test and multivariate discriminant function analysis. It was found that malignancy could be differentiated from benign cases of OBJ with a correct classification of 85.7 % when eight serum metabolites in combination with ratios of serum cholesterol were analysed. Significant alterations in serum tCho, Chol, CE and serum metabolites may have potential for early and differential non-invasive diagnosis of malignant and benign OBJ cases. It will further augment the novel insights of local and systemic effects in OBJ patients. 相似文献
1000.
Anita Chandra Febe van Maldegem Simon Andrews Michael S. Neuberger Cristina Rada 《Cell cycle (Georgetown, Tex.)》2013,12(5):732-742
CTNNBL1 is an armadillo-repeat protein that associates with the CDC5L/Prp19 complex of the spliceosome. Unlike the majority of spliceosomal proteins (and despite having no obvious homologs), CTNNBL1 is inessential for cell viability as revealed by studies in both vertebrate B cell lines and in fission yeast. Here, however, we show that ablation of CTNNBL1 in the mouse germline results in mid-gestation embryonic lethality but that lineage-specific CTNNBL1 ablation in early B cell precursors does not affect the production and abundance of mature B lymphocytes. However, CTNNBL1-deficient resting B lymphocytes show sluggish exit from quiescence on cell activation, although once entry into cycle has initiated, proliferation and differentiation in response to mitogenic stimuli continue largely unaffected. A similar sluggish exit from quiescence is also observed on reprovision of nutrients to nitrogen-starved CTNNBL1-deficient yeast. The results indicate that, whereas other RNA splicing-associated factors have been connected to cell cycle progression, CTNNBL1 plays no essential role in cycling cells but does fulfill an evolutionarily conserved function in helping cells to undergo efficient exit from quiescence following activation. 相似文献