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both nuclear size and dna amount contribute to midblastula transition timing in xenopus laevis.during early xenopus laevis embryogenesis both nuclear and cell volumes decrease with the nuclear-to-cytoplasmic (n/c) volume ratio reaching a maximum at the midblastula transition (mbt). at the mbt, embryonic transcription is upregulated and cell cycles lengthen. early studies demonstrated a role for the dna-to-cytoplasmic ratio in the control of mbt timing. by altering nuclear size, we previously showed that the n/c volume ratio also contributes to proper mbt timing. here we examine the relati ...201728801588
clathrodin, hymenidin and oroidin, and their synthetic analogues as inhibitors of the voltage-gated potassium channels.we have prepared three alkaloids from the agelas sponges, clathrodin, hymenidin and oroidin, and a series of their synthetic analogues, and evaluated their inhibitory effect against six isoforms of the kv1 subfamily of voltage-gated potassium channels, kv1.1-kv1.6, expressed in chinese hamster ovary (cho) cells using automated patch clamp electrophysiology assay. the most potent inhibitor was the (e)-n-(3-(2-amino-1h-imidazol-4-yl)allyl)-4,5-dichloro-1h-pyrrole-2-carboxamide (6g) with ic50 value ...201728802123
the crystal structure of full-length sizzled from xenopus laevis yields insights into wnt-antagonistic function of secreted frizzled-related proteins.the wnt-signaling pathway is crucial to cell proliferation, differentiation, and migration. the secreted frizzled-related proteins (sfrps) represent the largest family of secreted wnt inhibitors. however, their function in antagonizing wnt signaling has remained somewhat controversial. here, we report the crystal structure of sizzled from xenopus laevis, the first full-length structure of an sfrp. tethered by an inter-domain disulfide bond and a linker, the n-terminal cysteine-rich domain (crd) ...201728808056
assembly rules for gabaa receptor complexes in the brain.gabaa receptor (gabaar) pentamers are assembled from a pool of 19 subunits, and variety in subunit combinations diversifies gabaar functions to tune brain activity. pentamers with distinct subunit compositions localize differentially at synaptic and non-synaptic sites to mediate phasic and tonic inhibition, respectively. despite multitudes of theoretical permutations, limited subunit combinations have been identified in the brain. currently, no molecular model exists for combinatorial gabaar ass ...201728816653
dual control of pcdh8l/pcns expression and function in xenopus laevis neural crest cells by adam13/33 via the transcription factors tfap2α and arid3a.adam13/33 is a cell surface metalloprotease critical for cranial neural crest (cnc) cell migration. it can cleave multiple substrates including itself, fibronectin, ephrinb, cadherin-11, pcdh8 and pcdh8l (this work). cleavage of cadherin-11 produces an extracellular fragment that promotes cnc migration. in addition, the adam13 cytoplasmic domain is cleaved by gamma secretase, translocates into the nucleus and regulates multiple genes. here, we show that adam13 interacts with the arid3a/dril1/bri ...201728829038
advances in the use of xenopus for successful drug screening.understanding embryogenesis currently relies largely on the control of gene expression via several signaling pathways. many of the embryonic signaling pathways guiding embryological events are implicated in diseases that lack effective cure or treatment. because of the large number and size of the eggs, the rapid development of the embryos and the fact they are amenable to pharmacological, surgical and genetic techniques, xenopus laevis has been successfully used in searching for compounds that ...201728846034
toxicity effects of functionalized quantum dots, gold and polystyrene nanoparticles on target aquatic biological models: a review.nano-based products are widespread in several sectors, including textiles, medical-products, cosmetics, paints and plastics. nanosafety and safe-by-design are driving nanoparticle (np) production and applications through np functionalization (@nps). indeed, @nps frequently present biological effects that differ from the parent material. this paper reviews the impact of quantum dots (qds), gold nanoparticles (aunps), and polystyrene-cored nps (psnps), evidencing the role of np functionalization i ...201728858240
in vitro reconstitution of the endoplasmic reticulum.reconstitution of cellular organelles in vitro offers the possibility to perform quantitative and qualitative experiments in a controlled environment that cannot be done with the same accuracy in living cells. following a previous report, the subsequent list of protocols describes how to reconstitute and quantify a tubular er network in vitro based on purified microsomes from culture cells and cytosol from xenopus laevis egg extracts. biological material preparation and reconstitution assays req ...201728862340
methylisothiazolinone toxicity and inhibition of wound healing and regeneration in planaria.methylisothiazolinone (mit) is a common biocide used in cosmetic and industrial settings. studies have demonstrated that mit is a human sensitizer, to the extent that in 2013 mit was named allergen of the year. recently, we showed that mit exposure in xenopus laevis (the african clawed frog) inhibits wound healing and tail regeneration. however, it is unknown whether mit affects these processes in other animals. here, we investigated the effects of mit exposure in planaria-non-parasitic freshwat ...201728869924
loss of fourth electron-transferring tryptophan in animal (6-4) photolyase impairs dna repair activity in bacterial cells.(6-4) photolyases [(6-4)pls] are flavoproteins that use blue light to repair the ultraviolet-induced pyrimidine(6-4)pyrimidone photoproduct in dna. their flavin adenine dinucleotide (fad) cofactor can be reduced to its repair-active fadh- form by a photoinduced electron transfer reaction. in animal (6-4)pls, a chain of four trp residues was suggested to be involved in a stepwise transfer of an oxidation hole from the flavin to the surface of the protein. here, we investigated the effect of mutat ...201728880077
dextmp: deep dive into text for predicting moonlighting proteins.moonlighting proteins (mps) are an important class of proteins that perform more than one independent cellular function. mps are gaining more attention in recent years as they are found to play important roles in various systems including disease developments. mps also have a significant impact in computational function prediction and annotation in databases. currently mps are not labeled as such in biological databases even in cases where multiple distinct functions are known for the proteins. ...201728881966
interleukin-11 induces and maintains progenitors of different cell lineages during xenopus tadpole tail regeneration.unlike mammals, xenopus laevis tadpoles possess high ability to regenerate their lost organs. in amphibians, the main source of regenerated tissues is lineage-restricted tissue stem cells, but the mechanisms underlying induction, maintenance and differentiation of these stem/progenitor cells in the regenerating organs are poorly understood. we previously reported that interleukin-11 (il-11) is highly expressed in the proliferating cells of regenerating xenopus tadpole tails. here, we show that i ...201728887447
sumo co-expression modifies kv 11.1 channel activity.the voltage-gated potassium channel kv 11.1 is the molecular basis for the ikr current, which plays an important role in cardiac physiology. its malfunction is associated with both inherited and acquired cardiac arrhythmias. native currents differ from those in experimental models, suggesting additional regulatory mechanisms. we hypothesized that the post-translational modification sumoylation fine-tunes channel activity.201728888063
ultrafast flavin photoreduction in an oxidized animal (6-4) photolyase through an unconventional tryptophan tetrad.photolyases are flavoenzymes repairing uv-induced lesions in dna, which may be activated by a photoreduction of their fad cofactor. in most photolyases, this photoreduction proceeds by electron transfer along a chain of three tryptophan (trp) residues, connecting the flavin to the protein surface. much less studied, animal (6-4) photolyases (repairing pyrimidine-pyrimidone (6-4) photoproducts) are particularly interesting as they were recently shown to have a longer electron transfer chain, coun ...201728890968
the effect of 4-hydroxybenzaldehyde on the γ-aminobutyric acid type a receptor.the α1β2γ2 subtype of gabaa receptors is the most commonly found gabaa receptor subtype in the mammalian cortex and hippocampus. it is expressed heterologously in the xenopus laevis oocyte as a α1β2γ2s/l subtype for application as an in vitro model for the screening of compounds that modulate receptor activities. in fact, 4-hydroxybenzaldehyde (4-hb) has been identified as one of the major components in dendrocalamus asper bamboo shoots in our previous study, and the current study showed that at ...201728894409
depolarization of the conductance-voltage relationship in the nav1.5 mutant, e1784k, is due to altered fast inactivation.e1784k is the most common mixed long qt syndrome/brugada syndrome mutant in the cardiac voltage-gated sodium channel nav1.5. e1784k shifts the midpoint of the channel conductance-voltage relationship to more depolarized membrane potentials and accelerates the rate of channel fast inactivation. the depolarizing shift in the midpoint of the conductance curve in e1784k is exacerbated by low extracellular ph. we tested whether the e1784k mutant shifts the channel conductance curve to more depolarize ...201728898267
apetx4, a novel sea anemone toxin and a modulator of the cancer-relevant potassium channel kv10.1.the human ether-à-go-go channel (heag1 or kv10.1) is a cancer-relevant voltage-gated potassium channel that is overexpressed in a majority of human tumors. peptides that are able to selectively inhibit this channel can be lead compounds in the search for new anticancer drugs. here, we report the activity-guided purification and electrophysiological characterization of a novel kv10.1 inhibitor from the sea anemone anthopleura elegantissima. purified sea anemone fractions were screened for inhibit ...201728902151
models of convergent extension during morphogenesis.convergent extension (ce) is a fundamental and conserved collective cell movement that forms elongated tissues during embryonic development. thus far, studies have demonstrated two different mechanistic models of collective cell movements during ce. the first, termed the crawling mode, was discovered in the process of notochord formation in xenopus laevis embryos, and has been the established model of ce for decades. the second model, known as the contraction mode, was originally reported in stu ...028906063
collagen-embedded tumor transplantations in xenopus laevis tadpoles.the xenopus laevis tadpole provides a valuable model for studying tumorigenesis and tumor immunity by intravital real-time microscopy. using well-characterized thymic lymphoid tumor lines (15/0 and ff-2) that are transplantable into their compatible hosts (lg-15 isogenic clones and the f inbred strain, respectively), a system of semisolid tumor engraftment has been designed. because these lymphoid tumor cell lines are not adherent and grow in suspension, they are first immobilized in a matrix of ...201728912374
organ culture of the xenopus tadpole intestine.during xenopus metamorphosis, most tadpole organs remodel from the larval to adult form to prepare for adaptation to terrestrial life. organ culture serves as an important tool for studying larval-to-adult organ remodeling independent of the effects of other parts of the body. here, i introduce a protocol for organ culture in vitro using the xenopus laevis tadpole intestine before metamorphic climax. during culture in the absence of exogenous 3,3',5-triiodo-l-thyronine (t3), the most potent natu ...201728912375
molecular cloning and functional expression of the k+ channel kv7.1 and the regulatory subunit kcne1 from equine myocardium.the voltage-gated k+-channel kv7.1 and the subunit kcne1, encoded by the kcnq1 and kcne1 genes, respectively, are responsible for termination of the cardiac action potential. in humans, mutations in these genes can predispose patients to arrhythmias and sudden cardiac death (scd).201728917093
hmg-box factor soxd/sox15 and homeodomain-containing factor xanf1/hesx1 directly interact and regulate the expression of xanf1/hesx1 during early forebrain development in xenopus laevis.the homeodomain-containing transcription factor anf (also known as rpx/hesx1 in mammals) plays an important role during the forebrain development in vertebrates. here we demonstrate the ability of the xenopus laevis anf, xanf1/hesx1, to directly bind sry-related hmg-box-containing transcription factor soxd/sox15 and to cooperate with the latter during regulating of the expression of xanf1/hesx1 own gene. as we have shown by gst pull-down, emsa and the luciferase reporter assays, xanf1/hesx1 and ...028918251
β subunits control the effects of human kv4.3 potassium channel phosphorylation.the transient outward k+ current, ito, activates early in the cardiac myocyte action potential, to begin repolarization. human ito is generated primarily by two kv4.3 potassium channel α subunit splice variants (kv4.3l and kv4.3s) that diverge only by a c-terminal, membrane-proximal, 19-residue stretch unique to kv4.3l. protein kinase c (pkc) phosphorylation of threonine 504 within the kv4.3l-specific 19-residues mediates α-adrenergic inhibition of ito in human heart. kv4.3 is regulated in human ...201728919864
expression and functional proteomic analyses of osteocytes from xenopus laevis tested under mechanical stress conditions: preliminary observations on an appropriate new animal model.hitherto, the role of the osteocyte as transducer of mechanical stimuli into biological signals is far from settled. in this study, we used an appropriate model represented by the cortex of xenopus laevis long bone diaphysis lacking (unlike the mammalian one) of vascular structures and containing only osteocytes inside the bone matrix. these structural features allow any change of protein profile that might be observed upon different experimental conditions, such as bone adaptation to stress/mec ...201728925539
beyond mouse cancer models: three-dimensional human-relevant in vitro and non-mammalian in vivo models for photodynamic therapy.the proper design of experiments is a critical step for each study in order to obtain reproducible and reliable data. taking into account constant competitiveness in the quickly developing biomedical sciences and the availability of sophisticated techniques, the choice and establishment of an experimental model system are essential for a successful research project. currently, various sophisticated in vitro and in vivo models are being designed and developed in order to replace the use of mammal ...201728927532
the nitrate transporter family protein ljnpf8.6 controls the n-fixing nodule activity.n-fixing nodules are new organs formed on legume roots as a result of the beneficial interaction with soil bacteria, rhizobia. the nodule functioning is still a poorly characterized step of the symbiotic interaction, as only a few of the genes induced in n-fixing nodules have been functionally characterized. we present here the characterization of a member of the lotus japonicus nitrate transporter1/peptide transporter family, ljnpf8.6 the phenotypic characterization carried out in independent l ...201728931627
identification of regions responsible for the function of the plant k+ channels kat1 and akt2 in saccharomyces cerevisiae and xenopus laevis oocytes.the arabidopsis k+ channel kat1 complements in k+-limited medium the growth of the k+ uptake defective saccharomyces cerevisiae mutant strain cy162, while another k+ channel, akt2, does not. to gain insight into the structural basis for this difference, we constructed 12 recombinant chimeric channels from these two genes. when expressed in cy162, only three of these chimeras fully rescued the growth of cy162 under k+-limited conditions. we conclude that the transmembrane core region of kat1 is i ...201728933647
the brain is required for normal muscle and nerve patterning during early xenopus development.possible roles of brain-derived signals in the regulation of embryogenesis are unknown. here we use an amputation assay in xenopus laevis to show that absence of brain alters subsequent muscle and peripheral nerve patterning during early development. the muscle phenotype can be rescued by an antagonist of muscarinic acetylcholine receptors. the observed defects occur at considerable distances from the head, suggesting that the brain provides long-range cues for other tissue systems during develo ...201728943634
tumor immunology viewed from alternative animal models-the xenopus story.nonmammalian comparative animal models are important not only to gain fundamental evolutionary understanding of the complex interactions of tumors with the immune system, but also to better predict the applicability of novel immunotherapeutic approaches to humans. after reviewing recent advances in developing alternative models, we focus on the amphibian xenopus laevis and its usefulness in deciphering the perplexing roles of mhc class i-like molecules and innate (i)t cells in tumor immunity.201728944105
mammalian odorant receptor tuning breadth persists across distinct odorant panels.the molecular receptive range (mrr) of a mammalian odorant receptor (or) is the set of odorant structures that activate the or, while the distribution of these odorant structures across odor space is the tuning breadth of the or. variation in tuning breadth is thought to be an important property of ors, with the mrrs of these receptors varying from narrowly to broadly tuned. however, defining the tuning breadth of an or is a technical challenge. for practical reasons, a screening panel that broa ...201728945824
six1 and eya1 both promote and arrest neuronal differentiation by activating multiple notch pathway genes.the transcription factor six1 and its cofactor eya1 are important regulators of neurogenesis in cranial placodes, activating genes promoting both a progenitor state, such as hes8, and neuronal differentiation, such as neurog1. here, we use gain and loss of function studies in xenopus laevis to elucidate how these genes function during placodal neurogenesis. we first establish that hes8 is activated by notch signaling and represses neurog1 and neuronal differentiation, indicating that it mediates ...201728947179
complicated behavior of g-quadruplexes and evaluating g-quadruplexes' ligands in various systems mimicking cellular circumstance.environments surrounding g-rich sequences remarkably affect the conformations of these structures. a proper evaluation system mimicking the crowded environment in a cell with macromolecules should be developed to perform structural and functional studies on g-quadruplexes. in this study, the topology and stability of a g-quadruplex formed by human telomeric repeat sequences were investigated in a macromolecule-crowded environment created by polyethylene glycol 200 (peg200), tumor cell extract, a ...201628955851
expression and purification of the full murine npm2 and study of its interaction with protamines and histones.mouse nucleoplasmin m.npm2 was recombinantly expressed and the protein consisting of the complete sequence was purified and characterized. similar to its xenopus laevis x.npm2 counterpart, the protein forms stable pentameric complexes and exhibits an almost undistinguishable hydrodynamic ionic strength-dependent unfolding behavior. the interaction of n.pm2 with histones and mouse p1/p2 protamines revealed that these chromosomal proteins bind preferentially to the distal part of the nucleoplasmin ...201628955874
e-cigarette aerosol exposure can cause craniofacial defects in xenopus laevis embryos and mammalian neural crest cells.since electronic cigarette (ecig) introduction to american markets in 2007, vaping has surged in popularity. many, including women of reproductive age, also believe that ecig use is safer than traditional tobacco cigarettes and is not hazardous when pregnant. however, there are few studies investigating the effects of ecig exposure on the developing embryo and nothing is known about potential effects on craniofacial development. therefore, we have tested the effects of several aerosolized e-ciga ...201728957438
a comparison of electronic and traditional cigarette butt leachate on the development of xenopus laevis embryos.potential developmental toxicities of three different cigarette butt leachates were evaluated using the frog embryo teratogenesis assay-xenopus (fetax). xenopus laevis embryos were exposed to regular cigarette butt (rcb), menthol (mcb) and electronic (ecb) in concentrations ranging from 0 to 4 butts/l for rcb and mcb and 0-10 butts/l for ecb. the embryos were from stage 8 to 11 and were exposed for a 96-h period in static renewal test conditions. median lethal concentration (lc50), malformation ...201728959628
sequence and timing of early cranial skeletal development in xenopus laevis.xenopus laevis is widely used as a model organism in biological research. morphological descriptions of the larval cartilaginous skeleton are more than half a century old and comprehensive studies of early cartilage differentiation and development are missing. a proper understanding of early cranial skeletal development in x. laevis requires a detailed description that can function as a baseline for experimental studies. this basis makes it possible to evaluate skeletal defects produced by exper ...028960402
effect of allyl isothiocyanate on developmental toxicity in exposed xenopus laevis embryos.the pungent natural compound allyl isothiocyanate isolated from the seeds of cruciferous (brassica) plants such as mustard is reported to exhibit numerous beneficial health-promoting antimicrobial, antifungal, anticarcinogenic, cardioprotective, and neuroprotective properties. because it is also reported to damage dna and is toxic to aquatic organisms, the objective of the present study was to determine whether it possesses teratogenic properties. the frog embryo teratogenesis assay-xenopus (fet ...201528962355
differential cytolocation and functional assays of the two major human slc30a8 (znt8) isoforms.the non-synonymous single nucleotide polymorphism (snp) rs13266634 in human zinc transporter 8, znt8 (slc30a8), leads to a r325 variant, which is associated with an increased risk of developing type 2 diabetes (t2d). although the molecular details remain unknown, the mutation is thought to alter the kinetics of zinc transport into insulin granules in pancreatic β-cells. nevertheless, analysis of znt8 sequences from several animals shows that the amino acid at position 325 is poorly conserved. ap ...201728965566
the slc2a14 gene, encoding the novel glucose/dehydroascorbate transporter glut14, is associated with inflammatory bowel disease.background: variations in intestinal antioxidant membrane transporters are implicated in the initiation and progression of inflammatory bowel disease (ibd). facilitated glucose transporter member 14 (glut14), encoded by the solute carrier family 2 member 14 (slc2a14) gene, is a putative transporter for dehydroascorbic acid and glucose. although information on the gene is limited, shorter and longer glut14 isoforms have been identified. we hypothesized that glut14 mediates glucose and dehydroasco ...201728971850
desynchronizing embryonic cell division waves reveals the robustness of xenopus laevis development.the early xenopus laevis embryo is replete with dynamic spatial waves. one such wave, the cell division wave, emerges from the collective cell division timing of first tens and later hundreds of cells throughout the embryo. here, we show that cell division waves do not propagate between neighboring cells and do not rely on cell-to-cell coupling to maintain their division timing. instead, intrinsic variation in division period autonomously and gradually builds these striking patterns of cell divi ...201728978482
the effect of food properties on grasping and manipulation in the aquatic frog xenopus laevis.the ability to grasp an object is fundamental from an evolutionary perspective. involved in many daily activities, grasping has been extensively studied in primates and other mammals. yet other groups of tetrapods, including anurans, have also evolved significant forelimb prehensile capacities that are often thought to have originated in an arboreal context. in addition, grasping is also observed in aquatic species. but how aquatic frogs use their forelimbs to capture and manipulate prey remains ...201728982969
permeant-specific gating of connexin 30 hemichannels.gap junctions confer interconnectivity of the cytoplasm in neighboring cells via docking of two connexons expressed in each of the adjacent membranes. undocked connexons, referred to as hemichannels, may open and connect the cytoplasm with the extracellular fluid. the hemichannel configuration of connexins (cxs) displays isoform-specific permeability profiles that are not directly determined by the size and charge of the permeant. to further explore ca2+-mediated gating and permeability features ...201728982982
design of light-sensitive nmdars by genetically encoded photo-cross-linkers.genetic code expansion exploiting unnatural amino acids (uaas) is a powerful technique to create novel protein function in vivo. here, we provide a protocol for the incorporation of two uv-sensitive crosslinking uaas into nmda receptors (nmdars), a type of glutamate-gated ion channels mediating fast synaptic transmission. through heterologous expression in xenopus laevis oocytes, we have identified light-sensitive nmdars of glun2b subtype by using the two-electrode voltage electrophysiology meas ...201728986874
an inhibitor of thyroid hormone synthesis protects tail skin grafts transplanted to syngenic adult frogs.tail regression in amphibian tadpoles during metamorphosis is one of the most dynamic morphological changes in animal development and is induced by thyroid hormone (th). it has been proposed that tail resorption is driven by immunological rejection in xenopus laevis, based on experimental evidence showing that larval skin grafts become atrophic on syngenic recipient adult frogs. this led to the hypothesis that tail regression is induced by an immunological rejection against larval skin-specific ...201728990472
fanconi-anemia-associated mutations destabilize rad51 filaments and impair replication fork protection.fanconi anemia (fa) is a genetic disorder characterized by a defect in dna interstrand crosslink (icl) repair, chromosomal instability, and a predisposition to cancer. recently, two rad51 mutations were reported to cause an fa-like phenotype. despite the tight association of fa/hr proteins with replication fork (rf) stabilization during normal replication, it remains unknown how fa-associated rad51 mutations affect replication beyond icl lesions. here, we report that these mutations fail to prot ...201729020621
the first successful observation of in-cell nmr signals of dna and rna in living human cells.in order to understand intracellular biological events, information on the structure, dynamics and interaction of proteins and nucleic acids in living cells is of crucial importance. in-cell nmr is a promising method to obtain this information. although nmr signals of proteins in human cells have been reported, those of nucleic acids were reported only in xenopus laevis oocytes, i.e., not in human cells. here, dna and rna were introduced into human cells by means of pore formation by bacterial t ...201729022027
negative modulation of the gabaa ρ1 receptor function by l-cysteine.l-cysteine is an endogenous sulfur-containing amino acid with multiple and varied roles in the central nervous system, including neuroprotection and the maintenance of the redox balance. however, it was also suggested as an excitotoxic agent implicated in the pathogenesis of neurological disorders such as parkinson's and alzheimer's disease. l-cysteine can modulate the activity of ionic channels, including voltage-gated calcium channels and glutamatergic nmda receptors, whereas its effects on ga ...029023772
sonic hedgehog antagonists reduce size and alter patterning of the frog inner ear.sonic hedgehog (shh) signaling plays a major role in vertebrate development, from regulation of proliferation to the patterning of various organs. in amniotes, shh affects dorsoventral patterning in the inner ear but affects anteroposterior patterning in teleost ears. it remains unknown how altered function of shh relates to morphogenetic changes that coincide with the evolution of limbs and novel auditory organs in the ear. in this study, we used the tetrapod, xenopus laevis, to test how increa ...201729030893
pfkfb4 control of akt signaling is essential for premigratory and migratory neural crest formation.neural crest (nc) specification comprises an early phase, initiating immature nc progenitors formation at neural plate stage, and a later phase at neural fold stage, resulting in a functional premigratory nc that is able to delaminate and migrate. we found that the nc gene regulatory network triggers upregulation of pfkfb4 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4) during this late specification phase. as shown in previous studies, pfkfb4 controls akt signaling in gastrulas and gly ...201729038306
aprotinin prevents proteolytic epithelial sodium channel (enac) activation and volume retention in nephrotic syndrome.volume retention in nephrotic syndrome has been linked to activation of the epithelial sodium channel (enac) by proteolysis of its γ-subunit following urinary excretion of serine proteases such as plasmin. here we tested whether pharmacological inhibition of urinary serine protease activity might protect from enac activation and volume retention in nephrotic syndrome. urine from both nephrotic mice (induced by doxorubicin injection) and nephrotic patients exhibited high aprotinin-sensitive serin ...029042083
geraniin is a diuretic by inhibiting the na+:k+:2cl- cotransporter, nkcc2.geranium seemannii peyr is a perennial plant endemic in central mexico that has been widely used for its diuretic effect, but the responsible compound of this effect is unknown as well as the mechanism by which the diuretic effect is achieved. geraniin is one of the compounds isolated from this kind of geranium. this study was designed to determinate whether geraniin possesses diuretic activity and to elucidate the mechanism of action. geraniin was extracted and purified from geranium seemannii ...201729046296
a molecular atlas of the developing ectoderm defines neural, neural crest, placode, and nonneural progenitor identity in vertebrates.during vertebrate neurulation, the embryonic ectoderm is patterned into lineage progenitors for neural plate, neural crest, placodes and epidermis. here, we use xenopus laevis embryos to analyze the spatial and temporal transcriptome of distinct ectodermal domains in the course of neurulation, during the establishment of cell lineages. in order to define the transcriptome of small groups of cells from a single germ layer and to retain spatial information, dorsal and ventral ectoderm was subdivid ...201729049289
comparative early life stage toxicity of the african clawed frog, xenopus laevis following exposure to selected herbicide formulations applied to eradicate alien plants in south africa.the rise in pesticides application has increased the need for better understanding of their ecological impacts. the global amphibian declines, for example, have been positively correlated with pesticides use. the differential susceptibility in the developmental stages of amphibians to chemical substances are still largely unknown. we examined the 96-h differential toxicity responses of embryos, premetamorphic and transitional larval stage of xenopus laevis, to six formulated aquatic herbicide pr ...201729051999
rare gabra3 variants are associated with epileptic seizures, encephalopathy and dysmorphic features.genetic epilepsies are caused by mutations in a range of different genes, many of them encoding ion channels, receptors or transporters. while the number of detected variants and genes increased dramatically in the recent years, pleiotropic effects have also been recognized, revealing that clinical syndromes with various degrees of severity arise from a single gene, a single mutation, or from different mutations showing similar functional defects. accordingly, several genes coding for gabaa rece ...201729053855
maturation of xenopus laevis oocytes under cadmium and lead exposures: cell biology investigations.since amphibians are recognised as good models to assess the quality of environments, only few studies have dealt with the impacts of chemical contaminants on their gametes, while toxic effects at this stage will alter all the next steps of their life cycle. therefore, we propose to investigate the oocyte maturation of xenopus laevis in cadmium- and lead-contaminated conditions. the impacts of cadmium and lead ions were explored on events involved in the hormone-dependent process of maturation. ...201729053961
interaction of excitatory amino acid transporters 1 - 3 (eaat1, eaat2, eaat3) with n-carbamoylglutamate and n-acetylglutamate.inborn deficiency of the n-acetylglutamate synthase (nags) impairs the urea cycle and causes neurotoxic hyperammonemia. oral administration of n-carbamoylglutamate (ncg), a synthetic analog of n-acetylglutamate (nag), successfully decreases plasma ammonia levels in the affected children. due to structural similarities to glutamate, ncg may be absorbed in the intestine and taken up into the liver by excitatory amino acid transporters (eaats).201729055942
site-directed unnatural amino acid mutagenesis to investigate potassium channel pharmacology in xenopus laevis oocytes.unnatural amino acid mutagenesis is a useful tool enabling detailed investigation of ion channel structure-function relationships and pharmacology. methods have been developed to apply this technique to different heterologous systems for electrophysiological studies, with each system offering unique advantages and limitations. synthesis of aminoacylated-trna followed by injection into xenopus laevis oocytes is beneficial because it allows for the incorporation of a wide range of unnatural sidech ...029058197
xenbase: a genomic, epigenomic and transcriptomic model organism database.xenbase (www.xenbase.org) is an online resource for researchers utilizing xenopus laevis and xenopus tropicalis, and for biomedical scientists seeking access to data generated with these model systems. content is aggregated from a variety of external resources and also generated by in-house curation of scientific literature and bioinformatic analyses. over the past two years many new types of content have been added along with new tools and functionalities to reflect the impact of high-throughpu ...029059324
metabolic comparison of dorsal versus ventral cells directly in the live 8-cell frog embryo by microprobe single-cell ce-esi-ms.single-cell mass spectrometry (ms) empowers the characterization of metabolomic changes as cells differentiate to different tissues during early embryogenesis. using whole-cell dissection and capillary electrophoresis electrospray ionization (ce-esi) ms, we recently uncovered metabolic cell-to-cell differences in the 8- and 16-cell embryo of the south african clawed frog (xenopus laevis), raising the question whether metabolic cell heterogeneity is also detectable across the dorsal-ventral axis ...201729062391
regulatory remodeling in the allo-tetraploid frog xenopus laevis.genome duplication has played a pivotal role in the evolution of many eukaryotic lineages, including the vertebrates. a relatively recent vertebrate genome duplication is that in xenopus laevis, which resulted from the hybridization of two closely related species about 17 million years ago. however, little is known about the consequences of this duplication at the level of the genome, the epigenome, and gene expression.201729065907
aurora a activation in mitosis promoted by bugz.protein phase separation or coacervation has emerged as a potential mechanism to regulate biological functions. we have shown that coacervation of a mostly unstructured protein, bugz, promotes assembly of spindle and its matrix. bugz in the spindle matrix binds and concentrates tubulin to promote microtubule (mt) assembly. it remains unclear, however, whether bugz could regulate additional proteins to promote spindle assembly. in this study, we report that bugz promotes aurora a (aura) activatio ...029074706
reactivation of larval keratin gene (krt62.l) in blastema epithelium during xenopus froglet limb regeneration.limb regeneration is considered a form of limb redevelopment because of the molecular and morphological similarities. forming a regeneration blastema is, in essence, creating a developing limb bud in an adult body. this reactivation of a developmental process in a mature body is worth studying. xenopus laevis has a biphasic life cycle that involves distinct larval and adult stages. these distinct developmental stages are useful for investigating the reactivation of developmental processes in pos ...201729079423
development of xenopus laevis bipotential gonads into testis or ovary is driven by sex-specific cell-cell interactions, proliferation rate, cell migration and deposition of extracellular matrix.information on the mechanisms orchestrating sexual differentiation of the bipotential gonads into testes or ovaries in amphibians is limited. the aim of this study was to investigate the development of xenopus laevis gonad, to identify the earliest signs of sexual differentiation, and to describe mechanisms driving these processes. we used light and electron microscopy, immunofluorescence and cell tracing. in order to identify the earliest signs of sexual differentiation the sex of each tadpole ...201729080791
bioconcentration and metabolism of pyriproxyfen in tadpoles of african clawed frogs, xenopus laevis.bioconcentration and metabolism of pyriproxyfen uniformly labeled with 14c at the phenoxyphenyl ring were studied using tadpoles of african clawed frog, xenopus laevis, exposed to water at the nominal concentrations of 3 and 300 ppb for 22 days under the flow-through conditions, with a following 3 day depuration phase. neither meaningful mortality nor abnormal behavior was observed in control and exposure groups throughout the study. after the rapid uptake to tadpoles, pyriproxyfen was extensive ...201729084385
elicitation of xenopus laevis tadpole and adult frog peritoneal leukocytes.peritoneal lavage of xenopus laevis tadpoles and adult frogs is a reliable way of isolating resident and/or recruited innate immune populations. this protocol details the isolation of tadpole and adult amphibian (xenopus laevis) peritoneal leukocytes. the isolated cells are comprised predominantly of innate immune populations and chiefly of mononuclear and polymorphonuclear granulocytes. as described here, these cells are typically elicited by peritoneal injections of animals with heat-killed es ...201729084862
active site voltage clamp fluorometry of the sodium glucose cotransporter hsglt1.in the human sodium glucose cotransporter (hsglt1) cycle, the protein undergoes conformational changes where the sugar-binding site alternatively faces the external and internal surfaces. functional site-directed fluorometry was used to probe the conformational changes at the sugar-binding site. residues (y290, t287, h83, and n78) were mutated to cysteines. the mutants were expressed in xenopus laevis oocytes and tagged with environmentally sensitive fluorescent rhodamines [e.g., tetramethylrhod ...201729087341
abnormal creatine transport of mutations in monocarboxylate transporter 12 (mct12) found in patients with age-related cataract can be partially rescued by exogenous chaperone cd147.membrane transporters influence biological functions in the ocular lens. here, we investigate the monocarboxylate transporter 12 (mct12), also called creatine transporter 2 (crt2), which is found in the ocular lens and is involved in cataract. as the age-related form affects about half of the population world-wide, understanding relevant pathomechanisms is a prerequisite for exploring non-invasive treatments. we screened the coding exons of the gene slc16a12 in 877 patients from five cohorts, in ...201729088427
inheritance of histones h3 and h4 during dna replication in vitro.nucleosomes are believed to carry epigenetic information through the cell cycle, including through dna replication. it has been known for decades that parental histones are reassembled on newly replicated chromatin, but the mechanisms underlying histone inheritance and dispersal during dna replication are not fully understood. we monitored the fate of histones h3 or h4 from a single nucleosome through dna replication in two in vitro systems. in the sv40 system, histones assembled on a single nuc ...201729091772
vitamin a induced homeotic hindlimb formation on dorsal and ventral sides of regenerating tissue of amputated tails of japanese brown frog tadpoles.when anuran tadpoles are treated with vitamin a after tail amputation, hindlimb-like structures can be generated instead of the lost tail part at the amputation site. this homeotic transformation was initially expected to be a key to understanding the body plan of vertebrates. unfortunately, homeotic limb formation has been reproduced in only some indian frog species and a european species, but not in experimental anurans such as xenopus laevis or rana catesbeiana. consequently, this fascinating ...201729094344
effect of isothiocyanates, bitc and peitc, on stress protein accumulation, protein aggregation and aggresome-like structure formation in xenopus a6 kidney epithelial cells.numerous studies have elucidated the health benefits of organosulfur compounds, known as isothiocyanates (itcs), derived from cruciferous vegetables. as electrophiles, itcs have the ability to directly bind and modify thiol-containing compounds such as glutathione and cellular protein, including tubulin. while the biochemical effects of itcs have been well characterized, less information is available regarding their effects on the accumulation of stress-inducible heme oxygenase-1 (ho-1), heat sh ...029100952
frizzled-7 is required for xenopus heart development.wnt signalling regulates cardiogenesis during specification of heart tissue and the morphogenetic movements necessary to form the linear heart. wnt11-mediated non-canonical signalling promotes early cardiac development whilst wnt11-r, which is expressed later, also signals through the non-canonical pathway to promote heart development. it is unclear which frizzled proteins mediate these interactions. frizzled-7 (fzd7) is expressed during gastrulation in the mesodermal cells fated to become heart ...201729101100
identification of novel cis-regulatory elements of eya1 in xenopus laevis using bac recombineering.the multifunctional eya1 protein plays important roles during the development of cranial sensory organs and ganglia, kidneys, hypaxial muscles and several other organs in vertebrates. eya1 is encoded by a complex locus with candidate cis-regulatory elements distributed over a 329 kbp wide genomic region in xenopus. consequently, very little is currently known about how expression of eya1 is controlled by upstream regulators. here we use a library of xenopus tropicalis genomic sequences in bacter ...201729101371
influence of the rdl a301s mutation in the brown planthopper nilaparvata lugens on the activity of phenylpyrazole insecticides.we discovered the a301s mutation in the rdl gaba-gated chloride channel of fiprole resistant rice brown planthopper, nilaparvata lugens populations by dna sequencing and snp calling via rnaseq. ethiprole selection of two field n. lugens populations resulted in strong resistance to both ethiprole and fipronil and resulted in fixation of the a301s mutation, as well as the emergence of another mutation, q359e in one of the selected strains. to analyse the roles of these mutations in resistance to p ...201729107231
biophysical characterization of genetically encoded voltage sensor asap1: dynamic range improvement.recent work has introduced a new fluorescent voltage sensor, asap1, which can monitor rapid trains of action potentials in cultured neurons. this indicator is based on the gallus gallus voltage-sensitive phosphatase with the phosphatase domain removed and a circularly permuted gfp placed in the s3-s4 linker. however, many of the biophysical details of this indicator remain unknown. in this work, we study the biophysical properties of asap1. using the cut-open voltage clamp technique, we have sim ...201729108650
roles for xenopus aquaporin-3b (aqp3.l) during gastrulation: fibrillar fibronectin and tissue boundary establishment in the dorsal margin.aquaporins and aquaglyceroporins are a large family of membrane channel proteins that allow rapid movement of water and small, uncharged solutes into and out of cells along concentration gradients. recently, aquaporins have been gaining recognition for more complex biological roles than the regulation of cellular osmotic homeostasis. we have identified a specific expression pattern for xenopus aqp3b (also called aqp3.l) during gastrulation, where it is localized to the sensorial (deep) layer of ...029113748
the rice high-affinity k+ transporter oshkt2;4 mediates mg2+ homeostasis under high-mg2+ conditions in transgenic arabidopsis.rice (oryza sativa; background nipponbare) contains nine hkt (high-affinity k+ transport)-like genes encoding membrane proteins belonging to the superfamily of ktr/trk/hkt. oshkts have been proposed to include four selectivity filter-pore-forming domains homologous to the bacterial k+ channel kcsa, and are separated into oshkt1s with na+-selective activity and oshkt2s with na+-k+ symport activity. as a member of the oshkt2 subfamily, oshkt2;4 renders mg2+ and ca2+ permeability for yeast cells an ...201729114257
nuclear pore complex plasticity during developmental process as revealed by super-resolution microscopy.nuclear pore complex (npc) is of paramount importance for cellular processes since it is the unique gateway for molecular exchange through the nucleus. unraveling the modifications of the npc structure in response to physiological cues, also called nuclear pore plasticity, is key to the understanding of the selectivity of this molecular machinery. as a step towards this goal, we use the optical super-resolution microscopy method called direct stochastic optical reconstruction microscopy (dstorm) ...201729116248
wall following in xenopus laevis is barrier-driven.the tendency of animals to follow boundaries within their environment can serve as a strategy for spatial learning or defensive behaviour. we examined whether xenopus laevis tadpoles and froglets employ such a strategy by characterizing their swimming pattern in a square tank with shallow water. trajectories obtained from video recordings were analysed for proximity to the nearest wall. with the exception of young larvae, the vast majority of animals (both tadpoles and froglets) spent a dispropo ...201729119247
conservation of structure and function in vertebrate c-flip proteins despite rapid evolutionary change.cellular flice-like inhibitory protein (c-flip, gene symbol cflar) was first identified as a negative regulator of death receptor-mediated apoptosis in mammals. to understand the ubiquity and diversity of the c-flip protein subfamily during evolution, c-flip orthologs were identified from a comprehensive range of vertebrates, including birds, amphibians, and fish, and were characterized by combining experimental and computational analysis. predictions of three-dimensional protein structures and ...201529124180
towards functional selectivity for α6β3γ2 gabaa receptors: a series of novel pyrazoloquinolinones.the gabaa receptors are ligand-gated ion channels, which play an important role in neurotransmission. their variety of binding sites serves as an appealing target for many clinically relevant drugs. here, we explored the functional selectivity of modulatory effects at specific extracellular α+/β- interfaces, using a systematically varied series of pyrazoloquinolinones.201729127702
specific inhibition of gpcr-independent g protein signaling by a rationally engineered protein.activation of heterotrimeric g proteins by cytoplasmic nonreceptor proteins is an alternative to the classical mechanism via g protein-coupled receptors (gpcrs). a subset of nonreceptor g protein activators is characterized by a conserved sequence named the gα-binding and activating (gba) motif, which confers guanine nucleotide exchange factor (gef) activity in vitro and promotes g protein-dependent signaling in cells. gba proteins have important roles in physiology and disease but remain greatl ...201729133411
overland movement in african clawed frogs (xenopus laevis): empirical dispersal data from within their native range.dispersal forms are an important component of the ecology of many animals, and reach particular importance for predicting ranges of invasive species. african clawed frogs (xenopus laevis) move overland between water bodies, but all empirical studies are from invasive populations with none from their native southern africa. here we report on incidents of overland movement found through a capture-recapture study carried out over a three year period in overstrand, south africa. the maximum distance ...201729134157
it's not all black and white: visual scene parameters influence optokinetic reflex performance in xenopus laevis tadpoles.the maintenance of visual acuity during active and passive body motion is ensured by gaze-stabilizing reflexes that aim at minimizing retinal image slip. for the optokinetic reflex (okr), large-field visual motion of the surround forms the essential stimulus that activates eye movements. properties of the moving visual world influence cognitive motion perception and the estimation of visual image velocity. therefore, the performance of brainstem-mediated visuo-motor behaviors might also depend o ...201729141881
developmental changes in spinal neuronal properties, motor network configuration and neuromodulation at free-swimming stages of xenopus frog tadpoles.we describe a novel preparation of the isolated brainstem and spinal cord from pro-metamorphic tadpole stages of the south african clawed frog (xenopus laevis) that permits whole cell patch-clamp recordings from neurons in the ventral spinal cord. previous research on earlier stages of the same species has provided one of the most detailed understandings of the design and operation of a cpg circuit. here we have addressed how development sculpts complexity from this more basic circuit. the prepa ...201729142093
a nonredundant role for the trpm6 channel in neural tube closure.in humans, germline mutations in trpm6 cause autosomal dominant hypomagnesemia with secondary hypocalcemia disorder. loss of trpm6 in mice also perturbs cellular magnesium homeostasis but additionally results in early embryonic lethality and neural tube closure defects. to define the mechanisms by which trpm6 influences neural tube closure, we functionally characterized the role of trpm6 during early embryogenesis in xenopus laevis. the expression of xenopus trpm6 (xtrpm6) is elevated at the ons ...201729142255
functional properties and mechanism of action of pptq, an allosteric agonist and low nanomolar positive allosteric modulator at gabaa receptors.the former sedative-hypnotic and recreational drug methaqualone (quaalude) is a moderately potent, non-selective positive allosteric modulator (pam) at gabaa receptors (gabaars) (hammer et al., 2015). in the present study, we have identified a novel methaqualone analog, 2-phenyl-3-(p-tolyl)quinazolin-4(3h)-one (pptq), in a screening of 67 analogs at five αβ2γ2s gabaar subtypes and delineated its functional properties and mechanism of action at wild-type and mutant gabaars expressed in xenopus la ...029155148
4-aminopyridine: a pan voltage-gated potassium channel inhibitor that enhances kv 7.4 currents and inhibits noradrenaline-mediated contraction of rat mesenteric small arteries.kv 7.4 and kv 7.5 channels are regulators of vascular tone. 4-aminopyridine (4-ap) is considered a broad inhibitor of voltage-gated potassium (kv ) channels, with little inhibitory effect on kv 7 family members at mmol concentrations. however, the effect of 4-ap on kv 7 channels has not been systematically studied. the aim of this study was to investigate the pharmacological activity of 4-ap on kv 7.4 and kv 7.5 channels and characterize the effect of 4-ap on rat resistance arteries.201729156097
functional differences in transport properties of natural hkt1;1 variants influence shoot na+ exclusion in grapevine rootstocks.under salinity, vitis spp. rootstocks can mediate salt (nacl) exclusion from grafted v. vinifera scions enabling higher grapevine yields and production of superior wines with lower salt content. until now, the genetic and mechanistic elements controlling sodium (na+ ) exclusion in grapevine were unknown. using a cross between two vitis interspecific hybrid rootstocks, we mapped a dominant quantitative trait locus (qtl) associated with leaf na+ exclusion (nae) under salinity stress. the nae locus ...029160564
identification of isthmin 1 as a novel clefting and craniofacial patterning gene in humans.orofacial clefts are one of the most common birth defects, affecting 1-2 per 1000 births, and have a complex etiology. high-resolution array-based comparative genomic hybridization has increased the ability to detect copy number variants (cnvs) that can be causative for complex diseases such as cleft lip and/or palate. utilizing this technique on 97 nonsyndromic cleft lip and palate cases and 43 cases with cleft palate only, we identified a heterozygous deletion of isthmin 1 in one affected case ...029162626
regulation of kv1.4 potassium channels by pkc and ampk kinases.over the last years extensive kinase-mediated regulation of a number of voltage-gated potassium (kv) channels important in cardiac electrophysiology has been reported. this includes regulation of kv1.5, kv7.1 and kv11.1 cell surface expression, where the kinase-mediated regulation appears to center around the ubiquitin ligase nedd4-2. in the present study we examined whether kv1.4, constituting the cardiac ito,s current, is subject to similar regulation. in the epithelial madin-darby canine kidn ...029168928
effect of imidacloprid on the survival of xenopus tadpoles challenged with wild type frog virus 3.the sensitivity of amphibians to ranavirus may be increased by exposure to other environmental stressors, including chemical contaminants. neonicotinoid insecticides comprise 27% of the global insecticide market and have been detected in wetlands and other aquatic habitats. the present study focused on the effects of exposure of pre-metamorphic xenopus laevis to the neonicotinoid, imidacloprid (imi) on sensitivity to frog virus 3 (fv3) infection. it was hypothesized that exposure of tadpoles to ...029179150
targeted base editing via rna-guided cytidine deaminases in xenopus laevis embryos.genome editing using programmable nucleases such as crispr/cas9 or cpf1 has emerged as powerful tools for gene knock-out or knock-in in various organisms. while most genetic diseases are caused by point mutations, these genome-editing approaches are inefficient in inducing single-nucleotide substitutions. recently, cas9-linked cytidine deaminases, named base editors (bes), have been shown to convert cytidine to uridine efficiently, leading to targeted single-base pair substitutions in human cell ...201729179261
the r81t mutation in the nicotinic acetylcholine receptor of aphis gossypii is associated with neonicotinoid insecticide resistance with differential effects for cyano- and nitro-substituted neonicotinoids.the cotton aphid, aphis gossypii glover, is one of the most agriculturally important insect pests. neonicotinoid insecticides and sulfoxaflor have generally shown excellent control of a. gossypii, but these aphids have recently developed resistance against neonicotinoid insecticides. we previously characterized a field-collected a. gossypii kushima clone that showed higher resistance to nitro-substituted neonicotinoids, such as imidacloprid, than to cyano-substituted neonicotinoids, such as acet ...201729183611
quantification of size effect on protein rotational mobility in cells by 19f nmr spectroscopy.protein diffusion in living cells might differ significantly from that measured in vitro. little is known about the effect of globular protein size on rotational diffusion in cells because each protein has distinct surface properties, which result in different interactions with cellular components. to overcome this problem, the b1 domain of protein g (gb1) and several concatemers of the protein were labeled with 5-fluorotryptophan and studied by 19f nmr in escherichia coli cells, xenopus laevis ...201729184995
evaluating the longevity of surgically extracted xenopus laevis oocytes for the study of nematode ligand-gated ion channels.xenopus laevis oocytes have been extensively used as a heterologous expression system for the study of ion channels. while used successfully worldwide as tool for expressing and characterizing ion channels from a wide range of species, the limited longevity of oocytes once removed from the animal can pose significant challenges. in this study, we evaluate a simple and useful method that extends the longevity of xenopus oocytes after removal from the animal and quantitatively assessed the reliabi ...201729185074
tissue-specific gene inactivation in xenopus laevis: knockout of lhx1 in the kidney with crispr/cas9.studying genes involved in organogenesis is often difficult because many of these genes are also essential for early development. the allotetraploid frog, xenopus laevis, is commonly used to study developmental processes, but because of the presence of two homeologs for many genes, it has been difficult to use as a genetic model. few studies have successfully used crispr in amphibians, and currently there is no tissue-targeted knockout strategy described in xenopus the goal of this study is to d ...201729187504
the ectodomain of cadherin-11 binds to erbb2 and stimulates akt phosphorylation to promote cranial neural crest cell migration.during development, a multi-potent group of cells known as the cranial neural crest (cnc) migrate to form craniofacial structures. proper migration of these cells requires proteolysis of cell adhesion molecules, such as cadherins. in xenopus laevis, preventing extracellular cleavage of cadherin-11 impairs cnc migration. however, overexpression of the soluble cleavage product (ec1-3) is capable of rescuing this phenotype. the mechanism by which ec1-3 promotes cnc migration has not been investigat ...201729190819
spindle-to-cortex communication in cleaving frog eggs.during cytokinesis, the mitotic spindle communicates with the cell cortex to position a cleavage furrow that will cut through the cell in the plane defined by the metaphase plate. we investigated the molecular basis of this communication in xenopus laevis eggs, where the signal has to travel ∼400 µm in ∼30 min to reach the cortex from the first anaphase spindle. at anaphase onset, huge microtubule asters grow out from the poles of the spindle and meet at the plane previously defined by the metap ...201729196560
genomic epidemiology of the emerging pathogen batrachochytrium dendrobatidis from native and invasive amphibian species in chile.emerging fungal diseases represent a threat to food security, animal and human health worldwide. amphibian chytridiomycosis, caused by the fungus batrachochytrium dendrobatidis (bd), has been associated with catastrophic and well-documented amphibian population declines and extinctions. for the first time, bd was cultured from native and non-native wild amphibians in chile. phylogenomic analyses revealed that chilean isolates avs2, avs4 and avs7 group within the global panzootic lineage of bd (b ...201729205924
interaction of purinergic p2x4 and p2x7 receptor subunits.p2x4 and p2x7 are members of the p2x receptor family, comprising seven isoforms (p2x1-p2x7) that form homo- and heterotrimeric non-specific cation channels gated by extracellular atp. p2x4 and p2x7 are widely coexpressed, particularly in secretory epithelial cells and immune and inflammatory cells, and regulate inflammation and nociception. although functional heteromerization has been established for p2x2 and p2x3 subunits expressed in sensory neurons, there are contradictory reports regarding ...201729213241
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