117 research outputs found
Towards the Development of Broad-Spectrum Disease Resistance in Citrus
Transgenic plants expressing Cyclic nucleotide-gated channel (CNGC) and Bcell
lymphoma 2 (bcl-2) transgenes have been shown to be resistant to fungal and viral
pathogens. A PCR amplification product comprising CNGCcit open reading frame
(ORF) with Xba I and Eco RI ends was generated, inserted into pRTL22 plasmid,
transformed into E. coli, and sequenced. The 3.2 kb Hind III fragment of
pRTL22/CNGCcit containing the CaMV 35S promoter with dual enhancer, CNGCcit,
and CaMV 35S terminator was inserted into the Hind III site of pBin 34SGUS to
generate pBin35SCNGCcit construct, and transformed into E. coli. The cDNA clone of
bcl-2 in the pPTN binary vector was digested with Hind III to release a fragment
consisting of CaMV 35S promoter, bcl-2, and CaMV 35S terminator and inserted into
the Hind III site of pBin 34SGUS to generate pBin35SBcl-2 construct. These constructs
along with pPTN334Bcl-2 were used in Agrobacterium tumefaciens-mediated
transformation of sour orange rootstock, ?Rio Red?, ?Ruby Red? and ?Duncan? grapefruit
cultivars. The presence and expression of CNGCcit and bcl-2 in the transgenic plants was verified by b-glucuronidase histochemical assay, nptII enzyme-linked immunosorbent
assay, polymerase chain reaction, Southern blot, northern blot, relative quantitative
reverse transcription PCR , and quantitative real-time PCR. In this study, two transgenic
?Ruby Red? plants were successfully produced with an incorporated CNGCcit gene that
gave a positive result with all the analyses. None of the putative transgenic plants was
transgenic for bcl-2 gene based on Southern and northern analyses. Detached leaf assays
of the transgenic ?Ruby Red? plants showed an enhanced resistance to Xanthomonas
axonopodis pv. citri, Alternaria alternata, and Phytophthora nicotianae. Also, the leaves
did not show any sensitive response to tentoxin. The citrus cytosolic ascorbate
peroxidase (cAPXcit) genomic clone was isolated and characterized. Expression of
cAPXcit in ?Duncan?, non-transgenic control ?Ruby Red?, and ?Rio Red? was suppressed
due to A. alternata and P. nicotianae inoculations. However, an increased expression of
cAPXcit was observed in the inoculated transgenic ?Ruby Red? leaves
1,3-Bis(hydroxymethyl)benzimidazolin-2-one
The title compound, C9H10N2O3, crystallizes with one and a half molecules in the asymmetric unit, one lying on a general position and the other on a twofold rotation axis. The dihedral angle between the two independent benzimidazole ring systems is 18.96 (5)°. In the crystal, molecules are linked into a three-dimensional network by O—H⋯O hydrogen bonding involving N-hydroxymethyl and carbonyl groups, and C—H⋯O hydrogen bonds
DORN1/P2K1 and purino-calcium signalling in plants: making waves with extracellular ATP.
BACKGROUND AND AIMS:Extracellular ATP governs a range of plant functions, including cell viability, adaptation and cross-kingdom interactions. Key functions of extracellular ATP in leaves and roots may involve an increase in cytosolic free calcium as a second messenger ('calcium signature'). The main aim here was to determine to what extent leaf and root calcium responses require the DORN1/P2K1 extracellular ATP receptor in Arabidopsis thaliana. The second aim was to test whether extracellular ATP can generate a calcium wave in the root. METHODS:Leaf and root responses to extracellular ATP were reviewed for their possible links to calcium signalling and DORN1/P2K1. Leaves and roots of wild type and dorn1 plants were tested for cytosolic calcium increase in response to ATP, using aequorin. The spatial abundance of DORN1/P2K1 in the root was estimated using green fluorescent protein. Wild type roots expressing GCaMP3 were used to determine the spatial variation of cytosolic calcium increase in response to extracellular ATP. KEY RESULTS:Leaf and root ATP-induced calcium signatures differed markedly. The leaf signature was only partially dependent on DORN1/P2K1, while the root signature was fully dependent. The distribution of DORN1/P2K1 in the root supports a key role in the generation of the apical calcium signature. Root apical and sub-apical calcium signatures may operate independently of each other but an apical calcium increase can drive a sub-apical increase, consistent with a calcium wave. CONCLUSION:DORN1 could underpin several calcium-related responses but it may not be the only receptor for extracellular ATP in Arabidopsis. The root has the capacity for a calcium wave, triggered by extracellular ATP at the apex
Spontaneous Self-Assembly of Thermoresponsive Vesicles Using a Zwitterionic and an Anionic Surfactant.
Spontaneous formation of vesicles from the self-assembly of two specific surfactants, one zwitterionic (oleyl amidopropyl betaine, OAPB) and the other anionic (Aerosol-OT, AOT), is explored in water using small-angle scattering techniques. Two factors were found to be critical in the formation of vesicles: surfactant ratio, as AOT concentrations less than equimolar with OAPB result in cylindrical micelles or mixtures of micellar structures, and salt concentration, whereby increasing the amount of NaCl promotes vesicle formation by reducing headgroup repulsions. Small-angle neutron scattering measurements reveal that the vesicles are approximately 30-40 nm in diameter, depending on sample composition. Small-angle X-ray scattering measurements suggest preferential partitioning of OAPB molecules on the vesicle inner layer to support vesicular packing. Heating the vesicles to physiological temperature (37 °C) causes them to collapse into smaller ellipsoidal micelles (2-3 nm), with higher salt concentrations (≥10 mM) inhibiting this transition. These aggregates could serve as responsive carriers for loading or unloading of aqueous cargoes such as drugs and pharmaceuticals, with temperature changes serving as a simple release/uptake mechanism.Australian Research Council Future Fellowship (FT160100191) to Rico Tabor. and a Discovery Early Career Research Award (DE190100531) to Andrew Clulow
Erratum to: Changes in western disturbances over the Western Himalayas in a warming environment
Real-world clinical experience with Idebenone in the treatment of Leber hereditary optic neuropathy
Background:
Leber hereditary optic neuropathy (LHON) leads to bilateral central vision loss. In a clinical trial setting, idebenone has been shown to be safe and to provide a trend toward improved visual acuity, but long-term evidence of effectiveness in real-world clinical practice is sparse.
Methods:
Open-label, multicenter, retrospective, noncontrolled analysis of long-term visual acuity and safety in 111 LHON patients treated with idebenone (900 mg/day) in an expanded access program. Eligible patients had a confirmed mitochondrial DNA mutation and had experienced the onset of symptoms (most recent eye) within 1 year before enrollment. Data on visual acuity and adverse events were collected as per normal clinical practice. Efficacy was assessed as the proportion of patients with either a clinically relevant recovery (CRR) or a clinically relevant stabilization (CRS) of visual acuity. In the case of CRR, time to and magnitude of recovery over the course of time were also assessed.
Results:
At time of analysis, 87 patients had provided longitudinal efficacy data. Average treatment duration was 25.6 months. CRR was observed in 46.0% of patients. Analysis of treatment effect by duration showed that the proportion of patients with recovery and the magnitude of recovery increased with treatment duration. Average gain in best-corrected visual acuity for responders was 0.72 logarithm of the minimal angle of resolution (logMAR), equivalent to more than 7 lines on the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Furthermore, 50% of patients who had a visual acuity below 1.0 logMAR in at least one eye at initiation of treatment successfully maintained their vision below this threshold by last observation. Idebenone was well tolerated, with most adverse events classified as minor.
Conclusions:
These data demonstrate the benefit of idebenone treatment in recovering lost vision and maintaining good residual vision in a real-world setting. Together, these findings indicate that idebenone treatment should be initiated early and be maintained more than 24 months to maximize efficacy. Safety results were consistent with the known safety profile of idebenone
SPE-44 Implements Sperm Cell Fate
The sperm/oocyte decision in the hermaphrodite germline of Caenorhabditis elegans provides a powerful model for the characterization of stem cell fate specification and differentiation. The germline sex determination program that governs gamete fate has been well studied, but direct mediators of cell-type-specific transcription are largely unknown. We report the identification of spe-44 as a critical regulator of sperm gene expression. Deletion of spe-44 causes sperm-specific defects in cytokinesis, cell cycle progression, and organelle assembly resulting in sterility. Expression of spe-44 correlates precisely with spermatogenesis and is regulated by the germline sex determination pathway. spe-44 is required for the appropriate expression of several hundred sperm-enriched genes. The SPE-44 protein is restricted to the sperm-producing germline, where it localizes to the autosomes (which contain sperm genes) but is excluded from the transcriptionally silent X chromosome (which does not). The orthologous gene in other Caenorhabditis species is similarly expressed in a sex-biased manner, and the protein likewise exhibits autosome-specific localization in developing sperm, strongly suggestive of an evolutionarily conserved role in sperm gene expression. Our analysis represents the first identification of a transcriptional regulator whose primary function is the control of gamete-type-specific transcription in this system
Federated learning enables big data for rare cancer boundary detection.
Although machine learning (ML) has shown promise across disciplines, out-of-sample generalizability is concerning. This is currently addressed by sharing multi-site data, but such centralization is challenging/infeasible to scale due to various limitations. Federated ML (FL) provides an alternative paradigm for accurate and generalizable ML, by only sharing numerical model updates. Here we present the largest FL study to-date, involving data from 71 sites across 6 continents, to generate an automatic tumor boundary detector for the rare disease of glioblastoma, reporting the largest such dataset in the literature (n = 6, 314). We demonstrate a 33% delineation improvement for the surgically targetable tumor, and 23% for the complete tumor extent, over a publicly trained model. We anticipate our study to: 1) enable more healthcare studies informed by large diverse data, ensuring meaningful results for rare diseases and underrepresented populations, 2) facilitate further analyses for glioblastoma by releasing our consensus model, and 3) demonstrate the FL effectiveness at such scale and task-complexity as a paradigm shift for multi-site collaborations, alleviating the need for data-sharing
Author Correction: Federated learning enables big data for rare cancer boundary detection.
10.1038/s41467-023-36188-7NATURE COMMUNICATIONS14
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The impacts of climate change on the winter water cycle of the western Himalaya
Some 180 million people depend on the Indus River as a key water resource, fed largely by precipitation falling over the western Himalaya. However, the projected response of western Himalayan precipitation to climate change is currently not well constrained: CMIP5 GCMs project a reduced frequency and vorticity of synoptic-scale systems impacting the area, but such systems would exist in a considerably moister atmosphere.
In this study, a convection-permitting (4 km horizontal resolution) setup of the Weather Research and Forecasting (WRF) model is used to examine 40 cases of these synoptic-scale systems, known as western disturbances (WDs), as they interact with the western Himalaya. In addition to a present-day control run, three experiments are performed by perturbing the boundary and initial conditions to reflect pre-industrial, RCP4.5 and RCP8.5 background climates respectively.
It is found that in spite of the weakening intensity of WDs, net precipitation associated with them in future climate scenarios increases significantly; conversely there is no net change in precipitation between the pre-industrial and control experiments despite a significant conversion of snowfall in the pre-industrial experiment to rainfall in the control experiment, consistent with the changes seen in historical observations.
This shift from snowfall to rainfall has profound consequences on water resource management in the Indus Valley, where irrigation is dependent on spring meltwater. Flux decomposition shows that the increase in future precipitation follows directly from the projected moistening of the tropical atmosphere (which increases the moisture flux incident on the western Himalaya by 28%) overpowering the weakened dynamics (which decreases it by 20%).
Changes to extreme rainfall events are also examined: it is found that such events may increase significantly in frequency in both future scenarios examined.
Two-hour maxima rainfall events that currently occur in 1-in-8 WDs are projected to increase tenfold in frequency in the RCP8.5 scenario; more prolonged (one-week maxima) events are projected to increase fiftyfold
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