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surface contraction waves or cell proliferation waves in the presumptive neurectoderm during amphibian gastrulation: mexican axolotl versus african clawed frog.this essay represents a critical analysis of the literary data on various types of waves occurring in the amphibian embryos during gastrulation. a surface contraction wave travels through the presumptive neurectoderm during mexican axolotl gastrulation. this wave coincides temporally and spatially with involution of the inducing chordomesoderm and with the prospective neural plate. by contrast, there is no similar surface contraction wave during african clawed frog gastrulation. however, the cla ...202033181236
effects of copper on the neuromasts of xenopus laevis.fish and aquatic amphibians possess neuromasts on the surface of their body that constitute the lateral line, a sensory system used to detect water displacement. copper is known to inactivate the neuromast organs of this system. copper-induced neuromast loss in african clawed frogs, xenopus laevis, was examined by exposing nieuwkoop-faber stage 54-55 larvae to copper concentrations of 0, 100, 200, 300, and 400 µg/l for 96 h, followed by an examination of neuromast counts, staining intensity, and ...202033180147
ecotoxicological assessment of commercial boron nitride nanotubes toward xenopus laevis tadpoles and host-associated gut microbiota.despite the growing interest for boron nitride nanotubes (bnnt) due to their unique properties, data on the evaluation of the environmental risk potential of this emerging engineered nanomaterial are currently lacking. therefore, the ecotoxicity of a commercial form of bnnt (containing tubes, hexagonal-boron nitride, and boron) was assessed in vivo toward larvae of the amphibian xenopus laevis. following the exposure, multiple endpoints were measured in the tadpoles as well as in bacterial commu ...202033171057
mechanisms activating latent functions of pip aquaporin water channels via the interaction between pip1 and pip2 proteins.plant plasma-membrane type pip aquaporins are classified into two groups, pip1s and pip2s. in this study, we focused on hvpip1; 2, a pip1 in barley (hordeum vulgare), to dissect the molecular mechanisms that evoke hvpip1-mediated water transport. no hvpip1; 2 protein was localized to the plasma membrane when expressed alone in xenopus laevis oocytes. in contrast, a chimeric hvpip1; 2 protein (hvpip1; 2_24nc), in which the n- and c-terminal regions were replaced with the corresponding regions fro ...202033169164
epigenetic regulation of replication origin assembly: a role for histone h1 and chromatin remodeling factors.during early embryonic development in several metazoans, accurate dna replication is ensured by high number of replication origins. this guarantees rapid genome duplication coordinated with fast cell divisions. in xenopus laevis embryos this program switches to one with a lower number of origins at a developmental stage known as mid-blastula transition (mbt) when cell cycle length increases and gene transcription starts. consistent with this regulation, somatic nuclei replicate poorly when trans ...202033165968
synthesis of glun2a-selective nmda receptor antagonists with an electron-rich aromatic b-ring.glutamatergic n-methyl-d-aspartate (nmda) receptors are heterotetrameric ion channels that can be comprised of different subunits. glun2a subunit-containing nmda receptors are associated with diseases like anxiety, depression, and schizophrenia. however, the exact contribution of these nmda receptor subtypes is still unclear. to understand better the role of the glun2a-containing receptors, novel ligands were designed. in co-crystallization with the isolated binding site, tcn-201 (1) and analogs ...202033162207
trim-away mediated knock down uncovers a new function for lbh during gastrulation of xenopus laevis.we previously identified the protein lbh as necessary for cranial neural crest (cnc) cell migration in xenopus through the use of morpholinos. however, lbh is a maternally deposited protein and morpholinos achieve knockdowns through prevention of translation. in order to investigate the role of lbh in earlier embryonic events, we employed the new technique "trim-away" to degrade this maternally deposited protein. trim-away utilizes the e3 ubiquitin ligase trim21 to degrade proteins targeted with ...202033159936
kunitz-type peptides from the sea anemone heteractis crispa demonstrate potassium channel blocking and anti-inflammatory activities.the kunitz/bpti peptide family includes unique representatives demonstrating various biological activities. electrophysiological screening of peptides hcrg1 and hcrg2 from the sea anemone heteractis crispa on six kv1.x channel isoforms and insect shaker ir channel expressed in xenopus laevis oocytes revealed their potassium channels blocking activity. hcrg1 and hcrg2 appear to be the first kunitz-type peptides from sea anemones blocking kv1.3 with ic50 of 40.7 and 29.7 nm, respectively. in addit ...202033158163
development of antimicrobial peptides from amphibians.since the discovery of magainins from the skin secretions of the african toad xenopus laevis by michael zasloff in 1987, an increasing number of antimicrobial peptides (amps) has been identified in different anuran species and studied in detail [...].202033158031
periodic albinism of a widely used albino mutant of xenopus laevis caused by deletion of two exons in the hermansky-pudlak syndrome type 4 gene.the periodic albino mutant of xenopus laevis is a recessive mutant, in which reduced amounts of melanin appear in the retinal pigment epithelium (rpe) and in melanophores at the late embryonic stage, after which both rpe and melanophores gradually depigment. three types of pigment cells (melanophores, iridophores, and xanthophores) have been reported to be affected in this albino. however, the causative gene of the periodic albinism remains unknown. hermansky-pudlak syndrome (hps) is an autosoma ...202033147376
antimicrobial peptide induced-stress renders staphylococcus aureus susceptible to toxic nucleoside analogs.cationic antimicrobial peptides (amps) are active immune effectors of multicellular organisms and are also considered as new antimicrobial drug candidates. one of the problems encountered when developing amps as drugs is the difficulty of reaching sufficient killing concentrations under physiological conditions. here, using pexiganan, a cationic peptide derived from a host defense peptide of the african clawed frog and the first amp developed into an antibacterial drug, we studied whether sub-le ...202033133056
nicotinic acetylcholine receptors in the synganglion of the tick ixodes ricinus: functional characterization using membrane microtransplantation.nicotinic acetylcholine receptors are an important class of excitatory receptors in the central nervous system of arthropods. in the ticks ixodes ricinus, the functional and pharmacological properties of nicotinic receptors located in their neurons are still unknown. the objective of this study was to characterize the pharmacological properties of tick nicotinic receptors using membrane microtransplantation in xenopus laevis oocytes and two-electrodes voltage clamp method. the membranes microtra ...202033120248
observation of nucleic acids inside living human cells by in-cell nmr spectroscopy.the intracellular environment is highly crowded with biomacromolecules such as proteins and nucleic acids. under such conditions, the structural and biophysical features of nucleic acids have been thought to be different from those in vitro. to obtain high-resolution structural information on nucleic acids in living cells, the in-cell nmr method is a unique tool. following the first in-cell nmr measurement of nucleic acids in 2009, several interesting insights were obtained using xenopus laevis ...202033110737
high affinity na+ transport by wheat hkt1;5 is blocked by k.the wheat sodium transporters tmhkt1;5-a and tahkt1;5-d are encoded by genes underlying the major shoot na+ exclusion loci nax2 and kna1 from triticum monococcum (tm) and triticum aestivum (ta), respectively. in contrast to hkt2 transporters that have been shown to exhibit high affinity k+-dependent na+ transport, hkt1 proteins have, with one exception, only been shown to catalyze low affinity na+ transport and no k+ transport. here, using heterologous expression in xenopus laevis oocytes we unc ...202033103046
x-box-binding protein 1 is required for pancreatic development in xenopus laevis.x-box-binding protein 1 (xbp1) is a protein containing the basic leucine zipper structure. it belongs to the camp-response element binding protein (creb)/activating transcription factor transcription factor family. as the main transcription factor, spliced xbp1 (xbp1s) participates in many physiological and pathological processes and plays an important role in embryonic development. previous studies showed that xbp1-knockout mice died because of pancreatic exocrine function deficiency, indicatin ...202033098302
sclerostin inhibits wnt signaling through tandem interaction with two lrp6 ectodomains.low-density lipoprotein receptor-related protein 6 (lrp6) is a coreceptor of the β-catenin-dependent wnt signaling pathway. the lrp6 ectodomain binds wnt proteins, as well as wnt inhibitors such as sclerostin (sost), which negatively regulates wnt signaling in osteocytes. although lrp6 ectodomain 1 (e1) is known to interact with sost, several unresolved questions remain, such as the reason why sost binds to lrp6 e1e2 with higher affinity than to the e1 domain alone. here, we present the crystal ...202033097721
rad21 is involved in corneal stroma development by regulating neural crest migration.previously, we identified rad21r450c from a peripheral sclerocornea pedigree. injection of this rad21 variant mrna into xenopus laevis embryos disrupted the organization of corneal stroma fibrils. to understand the mechanisms of rad21-mediated corneal stroma defects, gene expression and chromosome conformation analysis were performed using cells from family members affected by peripheral sclerocornea. both gene expression and chromosome conformation of cell adhesion genes were affected in cells ...202033096935
disease-associated hcn4 v759i variant is not sufficient to impair cardiac pacemaking.the hyperpolarization-activated cation current if is a key determinant for cardiac pacemaker activity. it is conducted by subunits of the hyperpolarization-activated cyclic nucleotide-gated (hcn) channel family, of which hcn4 is predominant in mammalian heart. both loss-of-function and gain-of-function mutations of the hcn4 gene are associated with sinus node dysfunction in humans; however, their functional impact is not fully understood yet. here, we sought to characterize a hcn4 v759i variant ...202033095298
phosphoproteomic analysis of xenopus laevis reveals expression and phosphorylation of hypoxia-inducible pfkfb3 during dehydration.xenopus laevis tolerate dehydration when their environments evaporate during summer months. protein phosphorylation has previously shown to regulate important adaptations in x. laevis, including the transition to anaerobic metabolism. we therefore performed phosphoproteomic analysis of x. laevis to further elucidate the cellular and metabolic responses to dehydration. phosphoproteins were enriched in cellular functions and pathways related to glycolysis/gluconeogenesis, the tca cycle, and protei ...202033083755
derivation of proliferative islet1-positive cells during metamorphosis and wound response in xenopus.in mammalian hearts, cardiomyocytes retain a transient capacity to proliferate and regenerate following injury before birth, whereas they lose proliferative capacity immediately after birth. it has also been known that cardiac progenitor cells including islet1-positive cells do not contribute to the cardiac repair and regeneration in mammals. in contrast, hearts of zebrafish, amphibians and reptiles maintain a regenerative ability throughout life. here, we analyzed proliferative capacity of card ...202033070205
non-junctional role of cadherin3 in cell migration and contact inhibition of locomotion via domain-dependent, opposing regulation of rac1.classical cadherins are well-known adhesion molecules responsible for physically connecting neighboring cells and signaling this cell-cell contact. recent studies have suggested novel signaling roles for "non-junctional" cadherins (njcads); however, the function of cadherin signaling independent of cell-cell contacts remains unknown. in this study, mesendodermal cells and tissues from gastrula stage xenopus laevis embryos demonstrate that deletion of extracellular domains of cadherin3 (cdh3; for ...202033060598
scorpion toxin meunatxα-1 sensitizes primary nociceptors by selective modulation of voltage-gated sodium channels.venoms are a rich source of highly specific toxins, which allow the identification of novel therapeutic targets. we have now applied high content screening (hcs) microscopy to identify toxins that modulate pain sensitization signaling in primary sensory neurons of rat and elucidated the underlying mechanism. a set of venoms and fractions thereof were analyzed for their ability to activate type ii protein kinase a (pka-ii) and extracellular signal-regulated kinases (erk1/2). we identified meunatx ...202033051988
glutamate, d-(-)-2-amino-5-phosphonopentanoic acid, and n-methyl-d-aspartate do not directly modulate glycine receptors.replication studies play an essential role in corroborating research findings and ensuring that subsequent experimental works are interpreted correctly. a previously published paper indicated that the neurotransmitter glutamate, along with the compounds n-methyl-d-aspartate (nmda) and d-(-)-2-amino-5-phosphonopentanoic acid (ap5), acts as positive allosteric modulators of inhibitory glycine receptors. the paper further suggested that this form of modulation would play a role in setting the spina ...202033051383
evaluation of a multiplexed, multispecies nuclear receptor assay for chemical hazard assessment.sensitivity to potential endocrine disrupting chemicals in the environment varies across species and is influenced by sequence conservation of their nuclear receptor targets. here, we evaluated a multiplexed, in vitro assay testing receptors relevant to endocrine and metabolic disruption from five species. the trans-factorial™ system of human nuclear receptors was modified to include additional species: mouse (mus musculus), frog (xenopus laevis), zebrafish (danio rerio), chicken (gallus gallus) ...202033049310
whole-brain calcium imaging in larval xenopus.sensory systems detect environmental stimuli and transform them into electrical activity patterns interpretable by the central nervous system. en route to higher brain centers, the initial sensory input is successively transformed by interposed secondary processing centers. mapping the neuronal activity patterns at all of those stages is essential to understand sensory information processing. larval xenopus laevis is very well-suited for whole-brain imaging of neuronal activity. this is mainly d ...202033037078
elucidating the framework for specification and determination of the embryonic retina.how cell determination is regulated remains a major unsolved problem in developmental biology. the early embryonic rudiments of many tissues and organs are difficult or impossible to identify, isolate and study at the time when determination occurs. we have examined the commitment process leading to retina formation in xenopus laevis, where presumptive eye tissue can be identified and studied to assay its biological properties during the events leading up to determination. we find that for the r ...202033031807
microtubule-dependent pushing forces contribute to long-distance aster movement and centration in xenopus laevis egg extracts.during interphase of the eukaryotic cell cycle, the microtubule (mt) cytoskeleton serves as both a supportive scaffold for organelles and an arborized system of tracks for intracellular transport. at the onset of mitosis, the position of the astral mt network, specifically its center, determines the eventual location of the spindle apparatus and ultimately the cytokinetic furrow. positioning of the mt aster often results in its movement to the center of a cell, even in large blastomeres hundreds ...202033026931
cross-talk between p2x and nmda receptors.purinergic p2x receptors (p2x) are atp-gated ion channels widely expressed in the cns. while the direct contribution of p2x to synaptic transmission is uncertain, p2x reportedly affect n-methyl-d-aspartate receptor (nmdar) activity, which has given rise to competing theories on the role of p2x in the modulation of synapses. however, p2x have also been shown to participate in receptor cross-talk: an interaction where one receptor (e.g., p2x2) directly influences the activity of another (e.g., nic ...202033003406
dna content contributes to nuclear size control in xenopus laevis.cells adapt to drastic changes in genome quantity during evolution and cell division by adjusting the nuclear size to exert genomic functions. however, the mechanism by which dna content within the nucleus contributes to controlling the nuclear size remains unclear. here, we experimentally evaluated the effects of dna content by utilizing cell-free xenopus egg extracts and imaging of in vivo embryos. upon manipulation of dna content while maintaining cytoplasmic effects constant, both plateau si ...202032997613
torc1 selectively regulates synaptic maturation and input convergence in the developing visual system.newly synthesized proteins support the development of functional neural circuits and previous work has suggested that dysregulated translation mediates certain forms of autism spectrum disorder (asd). here, we investigated the role of target of rapamycin complex 1 (torc1) in synaptic and dendritic development in vivo in the retinotectal system of xenopus laevis tadpoles. we found that torc1 signaling regulates dendritic growth and branching and that acute over-activation of torc1 by rheb overexp ...202032996262
a survey of barley pip aquaporin ionic conductance reveals ca2+-sensitive hvpip2;8 na+ and k+ conductance.some plasma membrane intrinsic protein (pip) aquaporins can facilitate ion transport. here we report that one of the 12 barley pips (pip1 and pip2) tested, hvpip2;8, facilitated cation transport when expressed in xenopus laevis oocytes. hvpip2;8-associated ion currents were detected with na+ and k+, but not cs+, rb+, or li+, and was inhibited by ba2+, ca2+, and cd2+ and to a lesser extent mg2+, which also interacted with ca2+. currents were reduced in the presence of k+, cs+, rb+, or li+ relativ ...202032992595
inferring a complete genotype-phenotype map from a small number of measured phenotypes.understanding evolution requires detailed knowledge of genotype-phenotype maps; however, it can be a herculean task to measure every phenotype in a combinatorial map. we have developed a computational strategy to predict the missing phenotypes from an incomplete, combinatorial genotype-phenotype map. as a test case, we used an incomplete genotype-phenotype dataset previously generated for the malaria parasite's 'chloroquine resistance transporter' (pfcrt). wild-type pfcrt (pfcrt3d7) lacks signif ...202032991585
the mechanism of nmda receptor hyperexcitation in high pressure helium and hyperbaric oxygen.professional divers exposed to pressures greater than 1.1 mpa may suffer from the high pressure neurological syndrome (hpns). divers who use closed-circuit breathing apparatus face the risk of cns hyperbaric oxygen toxicity (hbotox). both syndromes are characterized by reversible cns hyperexcitability, accompanied by cognitive and motor deficits. previous studies have demonstrated that the hyperexcitability of hpns is induced mainly by nmda receptors (nmdars). in our recent studies, we demonstra ...202032982789
in-cell nmr spectroscopy of functional riboswitch aptamers in eukaryotic cells.we report here the in-cell nmr-spectroscopic observation of the binding of the cognate ligand 2'-deoxyguanosine to the aptamer domain of the bacterial 2'-deoxyguanosine-sensing riboswitch in eukaryotic cells, namely xenopus laevis oocytes and in human hela cells. the riboswitch is sufficiently stable in both cell types to allow for detection of binding of the ligand to the riboswitch. most importantly, we show that the binding mode established by in vitro characterization of this prokaryotic rib ...202032975353
design, synthesis, and in vitro evaluation of p2x7 antagonists.the p2x7 receptor is a promising target for the treatment of various diseases due to its significant role in inflammation and immune cell signaling. this work describes the design, synthesis, and in vitro evaluation of a series of novel derivatives bearing diverse scaffolds as potent p2x7 antagonists. our approach was based on structural modifications of reported (adamantan-1-yl)methylbenzamides able to inhibit the receptor activation. the adamantane moieties and the amide bond were replaced, an ...202032964578
endoparasites infecting exotic captive amphibian pet and zoo animals (anura, caudata) in germany.alongside exotic reptiles, amphibians, such as toads, frogs, salamanders, and newts, are nowadays considered popular pets worldwide. as reported for other exotic pet animals, amphibians are known to harbor numerous gastrointestinal parasites. nonetheless, very little data are available on captive amphibian parasitic diseases. in this study, we applied direct saline fecal smears (dsfs) to examine in total 161 stool samples from 41 different amphibian species belonging to the orders anura and caud ...202032960371
amiodarone bioconcentration and suppression of metamorphosis in xenopus.trace concentrations of a number of pharmaceutically active compounds have been detected in the aquatic environment in many countries, where they are thought to have the potential to exert adverse effects on non-target organisms. amiodarone (amd) is one such high-risk compound commonly used in general hospitals. amd is known to alter normal thyroid hormone (th) function, although little information is available regarding the specific mechanism by which this disruption occurs. anuran tadpole meta ...202032956954
aquaporin expression in the alimentary canal of the honey bee apis mellifera l. (hymenoptera: apidae) and functional characterization of am_eglp 1.aquaporins (aqp) are a family of plasma membrane proteins responsible for water transport through cell membranes. they are differentially expressed in different parts of the alimentary canal of insects where they regulate water transport. these proteins have been studied in detail in some insects, but few data are available for aquaporins of the honey bee, apis mellifera. we used quantitative pcr to study the expression of six putative aquaporin genes in forager honey bees. we found differential ...202032956406
do muscle contractile properties drive differences in locomotor performance in invasive populations of xenopus laevis in france?jumping and swimming are key locomotor traits in frogs intimately linked to survival and dispersal. french populations of the frog xenopus laevis from the invasion front are known to possess greater terrestrial locomotor endurance. here, we tested whether individuals from the invasion front show differences in their muscle physiology that may underlie the observed whole-organism performance differences. we measured muscle contractile properties of the isolated gastrocnemius muscle in vitro, incl ...202032955613
effect of 158 herbal remedies on human trpv1 and the two-pore domain potassium channels kcnk2, 3 and 9.herbal medicines are used to treat a broad number of maladies. however, the pharmacological profile of most remedies is poorly understood. we investigated the effect of herbal remedies from kampo, traditional chinese medicine (tcm) and other phytotherapies on human two-pore domain potassium channels (kcnk channels; trek-1, task-1 and task-3) as well as the human trpv1 channel. kcnk channels are responsible for the background potassium current of excitable cells, thus essential for the maintenanc ...202032953560
exposure impacts of environmentally relevant concentrations of a glufosinate ammonium herbicide formulation on larval development and thyroid histology of xenopus laevis.thyroid hormones play critical roles in body growth and development as well as reproduction. they also influence the activities of a wider variety of tissues and biological functions, such as osmoregulation, metabolism, and especially metamorphosis in organisms, such as frogs. these complex activities of thyroid hormones are prone to disruption by agricultural pesticides, often leading to modulation of growth and the reproductive system in particular. these substances include glufosinate ammoniu ...202032948887
an integrated approach to assess the sublethal effects of colloidal gold nanorods in tadpoles of xenopus laevis.gold nanorods (aunr) have been explored for many applications, including innovative nanomedicines, which also might contribute to its increase in the environment, namely due to inadequate disposable of wastes into aquatic environments. early-life stages of amphibians are usually aquatic and sensitive to chemical contamination. accordingly, this study aimed to determine the sublethal effects of ctab functionalized aunr on xenopus laevis tadpoles. as such, tadpoles were exposed to serial concentra ...202032947686
xenopus deep cell aggregates: a 3d tissue model for mesenchymal-to-epithelial transition.mesenchymal-to-epithelial transition (met) describes the ability of loosely associated migratory cells to form a more adherent sheet-like assembly of cells. met is a conserved motif occurring throughout organogenesis and plays a key role in regeneration and cancer metastasis, and is the first step in producing induced pluripotent stem cells (ipscs). to resolve fundamental biological questions about met, its relation to epithelial-to-mesenchymal transition, and to explore met's role in tissue ass ...202132939727
evolution of the endothelin pathway drove neural crest cell diversification.neural crest cells (nccs) are migratory, multipotent embryonic cells that are unique to vertebrates and form an array of clade-defining adult features. the evolution of nccs has been linked to various genomic events, including the evolution of new gene-regulatory networks1,2, the de novo evolution of genes3 and the proliferation of paralogous genes during genome-wide duplication events4. however, conclusive functional evidence linking new and/or duplicated genes to ncc evolution is lacking. endo ...202032939088
establishing embryonic territories in the context of wnt signaling.this review highlights the work that my research group has been developing, together with international collaborators, during the last decade. since we were able to establish xenopus laevis experimental model in brazil we have been focused on understanding early embryonic patterns regarding neural induction and axes establishment. in this context, wnt pathway appears as a major player and has been much explored by us and other research groups. here we chose to review three published works that w ...202032930371
using an aquatic model, xenopus laevis, to uncover the role of chromodomain 1 in craniofacial disorders.the chromodomain family member chromodomain 1 (chd1) has been shown to have numerous critical molecular functions including transcriptional regulation, splicing, and dna repair. complete loss of function of this gene is not compatible with life. on the other hand, missense and copy number variants of chd1 can result in intellectual disabilities and craniofacial malformations in human patients including cleft palate and pilarowski-bjornsson syndrome. we have used the aquatic developmental model o ...202032918369
acute consequences of a unilateral viiith nerve transection on vestibulo-ocular and optokinetic reflexes in xenopus laevis tadpoles.loss of peripheral vestibular function provokes severe impairments of gaze and posture stabilization in humans and animals. however, relatively little is known about the extent of the instantaneous deficits. this is mostly due to the fact that in humans a spontaneous loss often goes unnoticed initially and targeted lesions in animals are performed under deep anesthesia, which prevents immediate evaluation of behavioral deficits. here, we use isolated preparations of xenopus laevis tadpoles with ...202032915311
a collision coupling model governs the activation of neuronal girk1/2 channels by muscarinic-2 receptors.the g protein-activated inwardly rectifying k+-channel (girk) modulates heart rate and neuronal excitability. following g-protein coupled receptor (gpcr)-mediated activation of heterotrimeric g proteins (gαβγ), opening of the channel is obtained by direct binding of gβγ subunits. interestingly, girks are solely activated by gβγ subunits released from gαi/o-coupled gpcrs, despite the fact that all receptor types, for instance gαq-coupled, are also able to provide gβγ subunits. it is proposed that ...202032903404
lethal and teratogenic impacts of imazapyr, diquat dibromide, and glufosinate ammonium herbicide formulations using frog embryo teratogenesis assay-xenopus (fetax).globally, amphibians are experiencing widespread abnormalities and population declines. one potential contributor to these challenges is the use of pesticides, particularly aquatic herbicides applied to aquatic habitats inhabited by amphibians. critical issues of concern are the potential toxicity and teratogenicity of these herbicides towards amphibians. using the fetax protocol, three globally used formulations, including diquat dibromide (midstream), glufosinate ammonium (basta), and imazapyr ...202032901337
maximizing crispr/cas9 phenotype penetrance applying predictive modeling of editing outcomes in xenopus and zebrafish embryos.crispr/cas9 genome editing has revolutionized functional genomics in vertebrates. however, crispr/cas9 edited f0 animals too often demonstrate variable phenotypic penetrance due to the mosaic nature of editing outcomes after double strand break (dsb) repair. even with high efficiency levels of genome editing, phenotypes may be obscured by proportional presence of in-frame mutations that still produce functional protein. recently, studies in cell culture systems have shown that the nature of cris ...202032887910
tetrapeptide ac-haee-nh2 protects α4β2 nachr from inhibition by aβ.the cholinergic deficit in alzheimer's disease (ad) may arise from selective loss of cholinergic neurons caused by the binding of aβ peptide to nicotinic acetylcholine receptors (nachrs). thus, compounds preventing such an interaction are needed to address the cholinergic dysfunction. recent findings suggest that the 11evhh14 site in aβ peptide mediates its interaction with α4β2 nachr. this site contains several charged amino acid residues, hence we hypothesized that the formation of aβ-α4β2 nac ...202032872553
characterizing channelrhodopsin channel properties via two-electrode voltage clamp and kinetic modeling.two-electrode voltage clamp (tevc) is a preferred electrophysiological technique used to study gating kinetics and ion selectivity of light-activated channelrhodopsins (chrs). the method uses two intracellular microelectrodes to hold, or clamp, the membrane potential at a specific value and measure the flow of ions across the plasma membrane. here, we describe the use of tevc and a simple solution exchange protocol to measure cation selectivity and analyze gating kinetics of the c1c2 chimera exp ...202132865738
epigenetic control of myeloid cells behavior by histone deacetylase activity (hdac) during tissue and organ regeneration in xenopus laevis.in the present work we have focused on the histone deacetylase (hdac) control of myeloid cells behavior during xenopus tail regeneration. here we show that myeloid differentiation is crucial to modulate the regenerative ability of xenopus tadpoles in a hdac activity-dependent fashion. hdac activity inhibition during the first wave of myeloid differentiation disrupted myeloid cells dynamics in the regenerative bud as well the mrna expression pattern of myeloid markers, such as lurp, mpox, spib an ...202132858087
an aryl hydrocarbon receptor from the caecilian gymnopis multiplicata suggests low dioxin affinity in the ancestor of all three amphibian orders.the aryl hydrocarbon receptor (ahr) plays pleiotropic roles in the development and physiology of vertebrates in conjunction with xenobiotic and endogenous ligands. it is best known for mediating the toxic effects of dioxin-like pollutants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd). while most vertebrates possess at least one ahr that binds tcdd tightly, amphibian ahrs bind tcdd with very low affinity. previous analyses of ahrs from xenopus laevis (a frog; order anura) and ambystoma mexic ...202032858041
diversity of parasites from xenopus laevis (amphibia: pipidae) and their seasonal rate of infection in selected habitats in the limpopo province, south africa.this study determined the diversity and seasonality of parasites species of the african clawed frog, xenopus laevis (daudin, 1802), from three localities, namely modjadjikloof, mokopane and university of limpopo, limpopo province, south africa. a total of seven parasite species were collected and identified. they included two nematodes, camallanus kaapstaadi southwell & kirshner, 1937 and batrachocamallanus slomei (southwell & kirshner, 1937), a monogenean, protopolystoma xenopodis (price, 1943) ...202032855613
blood-brain barrier protein claudin-5 expressed in paired xenopus laevis oocytes mediates cell-cell interaction.claudin-5 determines the sealing properties of blood-brain barrier tight junctions and its function is impaired in neurodegenerative and neuroinflammatory disorders. focusing on the contribution of claudin-5 to the trans-interaction within the tight junction seal, we used xenopus laevis oocytes as an expression system. cells were clustered and challenged in a novel approach for the analysis of claudin interaction. we evaluated the strengthening effect of claudin-5 to cell-cell-connection in comp ...202032848831
a simple and efficient method for visualizing individual cells in vivo by cre-mediated single-cell labeling by electroporation (cremscle).efficient methods for visualizing cell morphology in the intact animal are of great benefit to the study of structural development in the nervous system. quantitative analysis of the complex arborization patterns of brain cells informs cell-type classification, dissection of neuronal circuit wiring, and the elucidation of growth and plasticity mechanisms. time-lapse single-cell morphological analysis requires labeling and imaging of single cells in situ without contamination from the ramified pr ...202032848634
na+ transporter svhkt1;1 from a halophytic turf grass is specifically upregulated by high na+ concentration and regulates shoot na+ concentration.we characterized an na+ transporter svhkt1;1 from a halophytic turf grass, sporobolus virginicus. svhkt1;1 mediated inward and outward na+ transport in xenopus laevis oocytes and did not complement k+ transporter-defective mutant yeast. svhkt1;1 did not complement athkt1;1 mutant arabidopsis, suggesting its distinguishable function from other typical hkt1 transporters. the transcript was abundant in the shoots compared with the roots in s. virginicus and was upregulated by severe salt stress (50 ...202032847126
preliminary indications that recombinant human il-16 attracts and stimulates lymphocytes of the amphibian, xenopus laevis implying an ancestral role for cd4 as a cytokine receptor.the d1 domain of the cd4 co-receptor interacts with mhc class ii during helper cd4+ th-cell activation and effector function in all gnathostomes but the sequence and structure of this region are not well conserved through phylogeny. conversely, the proximal d4 domain of cd4 is the binding site of the cytokine il-16 and is highly conserved, allowing for promiscuous binding of il-16 to cd4 between disparate gnathostomes. we report here that recombinant human il-16 (rhil-16) bound to xenopus lympho ...202032836028
dynamic expression of mmp28 during cranial morphogenesis.matrix metalloproteinases (mmps) are a large family of proteases comprising 24 members in vertebrates. they are well known for their extracellular matrix remodelling activity. mmp28 is the latest member of the family to be discovered. it is a secreted mmp involved in wound healing, immune system maturation, cell survival and migration. mmp28 is also expressed during embryogenesis in human and mouse. here, we describe the detailed expression profile of mmp28 in xenopus laevis embryos. we show tha ...202032829678
effect of obps on the response of olfactory receptors.the technique of two-electrode voltage-clamp (tevc) recording from the heterologous expression system of olfactory receptors (ors) in xenopus laevis oocytes has been widely used to deorphanize insect ors, that is to identify specific ligands for each of them. however, there is a controversial issue on whether ors are activated by the odorant/obp complex or the odorant alone. the mechanism of interaction among odorants, odorant-binding proteins (obps) and ors remains largely unknown, due to the l ...202032828257
new insights into hcptr2a and hcptr2b, two high-affinity peptide transporters from the ectomycorrhizal model fungus hebeloma cylindrosporum.while plants mainly rely on the use of inorganic nitrogen sources like ammonium and nitrate, soil-borne microorganisms like the ectomycorrhizal fungus hebeloma cylindrosporum can also take up soil organic n in the form of amino acids and peptides that they use as nitrogen and carbon sources. following the previous identification and functional expression in yeast of two ptr-like peptide transporters, the present study details the functions and substrates of hcptr2a and hcptr2b by analysing their ...202032820366
identification of the essential extracellular aspartic acids conserved in human monocarboxylate transporters 1, 2, and 4.human monocarboxylate transporters (hmcts) 1-4 transport monocarboxylates, such as l-lactate and pyruvate, as well as h+ across the plasma membrane. hmct1, 2, and 4 play important roles in energy balance, ph homeostasis. however, the molecular mechanism of these transporters, especially their ph dependency, remains unknown. the aim of this study was to identify the residues involved in the ph dependence of hmct1, 2, and 4. firstly, we focused on the effects of extracellular acids of hmct1. l-lac ...202032819565
a non-canonical role for the dna glycosylase neil3 in suppressing ape1 endonuclease-mediated ssdna damage.the dna glycosylase neil3 has been implicated in dna repair pathways including the base excision repair and the interstrand cross-link repair pathways via its dna glycosylase and/or ap lyase activity, which are considered canonical roles of neil3 in genome integrity. compared with the other dna glycosylases neil1 and neil2, xenopus laevis neil3 c terminus has two highly conserved zinc finger motifs containing grxf residues (designated as zf-grf). it has been demonstrated that the minor ap endonu ...202032817342
experiences with the marsupial frogs: reminiscences of a developmental biologist.this article provides a brief account of the career of eugenia m. del pino. casual events and serendipity played important roles in modeling her career as developmental biologist. in collaboration with colleagues and students, she analyzed the biology and development of the marsupial frog gastrotheca riobambae (family: hemiphractidae) in comparison with xenopus laevis and tropical frogs. the emphasis was placed on oogenesis and the early stages of development. topics include the mono- and multi- ...202032813268
design, synthesis, and electrophysiological evaluation of ns6740 derivatives: exploration of the structure-activity relationship for alpha7 nicotinic acetylcholine receptor silent activation.the α7 nicotinic acetylcholine receptor (nachr) silent agonists, able to induce receptor desensitization and promote the α7 metabotropic function, are emerging as new promising therapeutic anti-inflammatory agents. herein, we report the structure-activity relationship investigation of the archetypal silent agonist ns6740 (1,4-diazabicyclo[3.2.2]nonan-4-yl(5-(3-(trifluoromethyl)-phenyl)-furan-2-yl)methanone) (1) to elucidate the ligand-receptor interactions responsible for the α7 silent activatio ...202032810771
α-conotoxin as potential to α7-nachr recombinant expressed in escherichia coli.α7 nicotinic acetylcholine receptors (nachr) is an important nicotinic acetylcholine receptors subtype and closely associated with cognitive disorders, such as alzheimer's and schizophrenia disease. the mutant arib (v11l, v16a) of α-conotoxin arib with 17-amino acid residues specifically targets α7 nachr with no obvious effect on other nachr subtypes. in the study, the synthetic gene encoding mature peptide of arib and mutant arib (v11l, v16a) carried a fusion protein trx and 6 × his-tag was sep ...202032806654
compaction of rna duplexes in the cell.the structure and flexibility of rna depends sensitively on the microenvironment. using pulsed electron-electron double-resonance (peldor)/double electron-electron resonance (deer) spectroscopy combined with advanced labeling techniques, we show that the structure of double-stranded rna (dsrna) changes upon internalization into xenopus laevis oocytes. compared to dilute solution, the dsrna a-helix is more compact in cells. we recapitulate this compaction in a densely crowded protein solution. at ...202032804430
mucociliary epithelial organoids from xenopus embryonic cells: generation, culture and high-resolution live imaging.mucociliary epithelium provides the first line of defense by removing foreign particles through the action of mucus production and cilia-mediated clearance. many clinically relevant defects in the mucociliary epithelium are inferred as they occur deep within the body. here, we introduce a tractable 3d model for mucociliary epithelium generated from multipotent progenitors that were microsurgically isolated from xenopus laevis embryos. the mucociliary epithelial organoids are covered with newly g ...202032804169
conservation of glomerular organization in the main olfactory bulb of anuran larvae.the glomerular array in the olfactory bulb of many vertebrates is segregated into molecularly and anatomically distinct clusters linked to different olfactory functions. in anurans, glomerular clustering is so far only described in xenopus laevis. we traced olfactory projections to the bulb in tadpoles belonging to six distantly related anuran species in four families (pipidae, hylidae, bufonidae, dendrobatidae) and found that glomerular clustering is remarkably conserved. the general bauplan co ...202032792916
mutation affecting the conserved acidic wnk1 motif causes inherited hyperkalemic hyperchloremic acidosis.gain-of-function mutations in with no lysine (k) 1 (wnk1) and wnk4 genes are responsible for familial hyperkalemic hypertension (fhht), a rare, inherited disorder characterized by arterial hypertension and hyperkalemia with metabolic acidosis. more recently, fhht-causing mutations in the kelch-like 3-cullin 3 (klhl3-cul3) e3 ubiquitin ligase complex have shed light on the importance of wnk's cellular degradation on renal ion transport. using full exome sequencing for a 4-generation family and th ...202032790646
monocarboxylate transporter 12 as a guanidinoacetate efflux transporter in renal proximal tubular epithelial cells.guanidinoacetate (gaa), which is a precursor of creatine, is mainly biosynthesized in the renal proximal tubular epithelial cells (rptecs). plasma concentration of gaa has been reported to be reduced in patients with monocarboxylate transporter 12 (mct12) mutation (p.q215x). however, the mechanism underlying gaa release from the rptecs remains unclear. therefore, to elucidate the role of mct12 in renal gaa release, mct12-mediated gaa transport was evaluated using the human and rat mct12-expressi ...202032781157
heterogeneity of synonymous substitution rates in the xenopus frog genome.with the increasing availability of high quality genomic data, there is opportunity to deeply explore the genealogical relationships of different gene loci between closely related species. in this study, we utilized genomes of xenopus laevis (xla, a tetraploid species with (l) and (s) sub-genomes) and x. tropicalis (xtr, a diploid species) to investigate whether synonymous substitution rates among orthologous or homoeologous genes displayed any heterogeneity. from over 1500 orthologous/homoeolog ...202032764757
the specific molecular composition and structural arrangement of eleutherodactylus coqui gular skin tissue provide its high mechanical compliance.a male eleutherodactylus coqui (ec, a frog) expands and contracts its gular skin to a great extent during mating calls, displaying its extraordinarily compliant organ. there are striking similarities between frog gular skin and the human bladder as both organs expand and contract significantly. while the high extensibility of the urinary bladder is attributed to the unique helical ultrastructure of collagen type iii, the mechanism behind the gular skin of ec is unknown. we therefore aim to under ...202032764252
sequential purification and characterization of torpedo californica nachr-dc supplemented with chs for high-resolution crystallization studies.over the past 10 years we have been developing a multi-attribute analytical platform that allows for the preparation of milligram amounts of functional, high-pure, and stable torpedo (muscle-type) nachr detergent complexes for crystallization purpose. in the present work, we have been able to significantly improve and optimize the purity and yield of nicotinic acetylcholine receptors in detergent complexes (nachr-dc) without compromising stability and functionality. we implemented new methods in ...202032763308
comparative gene expression profiling between optic nerve and spinal cord injury in xenopus laevis reveals a core set of genes inherent in successful regeneration of vertebrate central nervous system axons.the south african claw-toed frog, xenopus laevis, is uniquely suited for studying differences between regenerative and non-regenerative responses to cns injury within the same organism, because some cns neurons (e.g., retinal ganglion cells after optic nerve crush (onc)) regenerate axons throughout life, whereas others (e.g., hindbrain neurons after spinal cord injury (sci)) lose this capacity as tadpoles metamorphose into frogs. tissues from these cns regions (frog onc eye, tadpole sci hindbrai ...202032758133
grp94 regulates the recruitment of aneural achr clusters for the assembly of postsynaptic specializations by modulating adf/cofilin activity and turnover.temperature is a physiological factor that affects neuronal growth and synaptic homeostasis at the invertebrate neuromuscular junctions (nmjs); however, whether temperature stress could also regulate the structure and function of the vertebrate nmjs remains unclear. in this study, we use xenopus laevis primary cultures as a vertebrate model system for investigating the involvement of heat shock protein 90 (hsp90) family of stress proteins in nmj development. first, cold temperature treatment or ...202032747457
exploring the relationships between amphibian (xenopus laevis) myeloid cell subsets.the differentiation of distinct leukocyte subsets is governed by lineage-specific growth factors that elicit disparate expression of transcription factors and markers by the developing cell populations. for example, macrophages (mφs) and granulocytes (grns) arise from common granulocyte-macrophage progenitors in response to distinct myeloid growth factors. in turn, myelopoiesis of the xenopus laevis anuran amphibian appears to be unique to other studied vertebrates in several respects while the ...202032745480
analysis of pallial/cortical interneurons in key vertebrate models of testudines, anurans and polypteriform fishes.the organization of the pallial derivatives across vertebrates follows a comparable elementary arrangement, although not all of them possess a layered cortical structure as sophisticated as the cerebral cortex of mammals. however, its expansion along evolution has only been possible by the development and coevolution of the cellular networks formed by excitatory neurons and inhibitory interneurons. thus, the comparative analysis of interneuron types in vertebrate models of key evolutionary signi ...202032743670
rare heterozygous gdf6 variants in patients with renal anomalies.although over 50 genes are known to cause renal malformation if mutated, the underlying genetic basis, most easily identified in syndromic cases, remains unsolved in most patients. in search of novel causative genes, whole-exome sequencing in a patient with renal, i.e., crossed fused renal ectopia, and extrarenal, i.e., skeletal, eye, and ear, malformations yielded a rare heterozygous variant in the gdf6 gene encoding growth differentiation factor 6, a member of the bmp family of ligands. previo ...202032737436
new insights in the mode of action of (+)-erythravine and (+)-11α-hydroxy-erythravine alkaloids.erythrinian alkaloids ((+)-erythravine and (+)-11-α-hydroxy-erythravine) have been pointed as the main responsible agents for the anticonvulsant and anxiolytic properties of erythrina mulungu mart ex benth. the present work provides a new set of information about the mode of action of these alkaloids by the use of a complementary approach of neurochemical and electrophysiological assays. we propose here that the antiepileptic and anxiolytic properties exhibited by both alkaloids appear not to be ...202032735983
zinc protection of fertilized eggs is an ancient feature of sexual reproduction in animals.one of the earliest and most prevalent barriers to successful reproduction is polyspermy, or fertilization of an egg by multiple sperm. to prevent these supernumerary fertilizations, eggs have evolved multiple mechanisms. it has recently been proposed that zinc released by mammalian eggs at fertilization may block additional sperm from entering. here, we demonstrate that eggs from amphibia and teleost fish also release zinc. using xenopus laevis as a model, we document that zinc reversibly block ...202032735558
embryonic epidermal lectins in three amphibian species, rana ornativentris, bufo japonicus formosus, and cynops pyrrhogaster.intelectins (itlns) are secretory lectins found in several chordate species that recognize carbohydrates on the bacterial cell surface depending on ca2+ . in newly hatched larvae of rana ornativentris (r. orn), bufo japonicus formosus (b. jpn), and cynops pyrrhogaster (c. pyr), an anti-itln monoclonal antibody (mab) labeled a subset of epidermal cells in whole-mount immunocytochemical assays. in western blot analyses, the mab identified protein bands at approximately 33-37 kda in the larval extr ...202032729712
polyploidization and pseudogenization in allotetraploid frog xenopus laevis promote the evolution of aquaporin family in higher vertebrates.aquaporins (aqps), as members of the major intrinsic protein (mip) superfamily, facilitated the permeation of water and other solutes and are involved in multiple biological processes. aqp family exists in almost all living organisms and is highly diversified in vertebrates in both classification and function due to genome wide duplication. while some aqp orthologs have been lost in higher vertebrates through evolution.202032727380
postsynaptic and presynaptic nmdars have distinct roles in visual circuit development.to study contributions of n-methyl-d-aspartate receptors (nmdars) in presynaptic and postsynaptic neurons of the developing visual system, we microinject antisense morpholino oligonucleotide (mo) against glun1 into one cell of two-cell-stage xenopus laevis embryos. the resulting bilateral segregation of mo induces postsynaptic nmdar (postnmdar) knockdown in tectal neurons on one side and presynaptic nmdar (prenmdar) knockdown in ganglion cells projecting to the other side. postnmdar knockdown re ...202032726620
defective heart chamber growth and myofibrillogenesis after knockout of adprhl1 gene function by targeted disruption of the ancestral catalytic active site.adp-ribosylhydrolase-like 1 (adprhl1) is a pseudoenzyme expressed in the developing heart myocardium of all vertebrates. in the amphibian xenopus laevis, knockdown of the two cardiac adprhl1 protein species (40 and 23 kda) causes failure of chamber outgrowth but this has only been demonstrated using antisense morpholinos that interfere with rna-splicing. transgenic production of 40 kda adprhl1 provides only part rescue of these defects. crispr/cas9 technology now enables targeted mutation of the ...202032726316
gitx1(β/κ-theraphotoxin-gi1a), a novel toxin from the venom of brazilian tarantula grammostola iheringi (mygalomorphae, theraphosidae): isolation, structural assessments and activity on voltage-gated ion channels.spider venoms, despite their toxicity, represent rich sources of pharmacologically active compounds with biotechnological potential. however, in view of the large diversity of the spider species, the full potential of their venom molecules is still far from being known. in this work, we report the purification and structural and functional characterization of gitx1 (β/κ-trtx-gi1a), the first toxin purified from the venom of the brazilian tarantula spider grammostola iheringi. gitx1 was purified ...202032717411
nicotinic acetylcholine receptors: ex-vivo expression of functional, non-hybrid, heteropentameric receptors from a marine arthropod, lepeophtheirus salmonis.nicotinic acetylcholine receptors (nachrs) are ligand-gated ion channels mostly located in the post-synaptic membrane of cholinergic synapses. the natural neurotransmitter is acetylcholine, but they are also the direct targets for neonicotinoids, chemicals widely used against ectoparasites, arthropod vectors and agricultural pests. there are significant concerns regarding adverse effects of neonicotinoids on beneficial insects. in arthropods, functional nachrs made of α subunits have been expres ...202032716968
l-glutamic acid monosodium salt reduces the harmful effect of lithium on the development of xenopus laevis embryos.many xenobiotics in the environment affect the human body in various ways. among those xenobiotics, lithium chloride (li, licl) and monosodium glutamate (l-glutamic acid monosodium salt, msg) compounds affect the crucial processes of stem cell differentiation, cell proliferation, developmental gene expression, and overall development in animals. in this study, we aimed to examine the developmental effects of exposure to flavor enhancer msg and lici medicament on xenopus embryos using the frog em ...202032705564
redox priming promotes aurora a activation during mitosis.cell cycle-dependent redox changes can mediate transient covalent modifications of cysteine thiols to modulate the activities of regulatory kinases and phosphatases. our previously reported finding that protein cysteine oxidation is increased during mitosis relative to other cell cycle phases suggests that redox modifications could play prominent roles in regulating mitotic processes. the aurora family of kinases and their downstream targets are key components of the cellular machinery that ensu ...202032694171
intracellular motor-driven transport of rodlike smooth organelles along microtubules.molecular motors are fascinating proteins that use the energy of atp hydrolysis to drive vesicles and organelles along cytoskeleton filaments toward their final destination within the cell. several copies of these proteins bind to the cargo and take turns transporting the cargo attaching to and detaching from the track stochastically. despite the relevance of molecular motors to cell physiology, key aspects of their collective functioning are still unknown. in this work we propose a one-dimensio ...202032688554
preventing ethanol-induced brain and eye morphology defects using optogenetics.background: embryonic exposure to the teratogen ethanol leads to dysmorphias, including eye and brain morphology defects associated with fetal alcohol spectrum disorder (fasd). exposure of xenopus laevis embryos to ethanol leads to similar developmental defects, including brain and eye dysmorphism, confirming our work and the work of others showing xenopus as a useful system for studies of the brain and eye birth defects associated with fasd. several targets of ethanol action have been hypothesi ...201932685918
phosphorylation influences water and ion channel function of atpip2;1.the phosphorylation state of two serine residues within the c-terminal domain of atpip2;1 (s280, s283) regulates its plasma membrane localization in response to salt and osmotic stress. here, we investigated whether the phosphorylation state of s280 and s283 also influence atpip2;1 facilitated water and cation transport. a series of single and double s280 and s283 phosphomimic and phosphonull atpip2;1 mutants were tested in heterologous systems. in xenopus laevis oocytes, phosphomimic mutants at ...202032678928
predation threats for a 24-h period activated the extension of axons in the brains of xenopus tadpoles.the threat of predation is a driving force in the evolution of animals. we have previously reported that xenopus laevis enhanced their tail muscles and increased their swimming speeds in the presence of japanese larval salamander predators. herein, we investigated the induced gene expression changes in the brains of tadpoles under the threat of predation using 3'-tag digital gene expression profiling. we found that many muscle genes were expressed after 24 h of exposure to predation. ingenuity p ...202032678123
electrophysiological effects of non-vitamin k antagonist oral anticoagulants on atrial repolarizing potassium channels.non-vitamin k antagonist oral anticoagulants (noacs) are widely used in the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (af). the efficacy of noacs has been attributed in part to pleiotropic effects that are mediated through effects on thrombin, factor xa, and their respective receptors. direct pharmacological effects of noacs and cardiac ion channels have not been addressed to date. we hypothesized that the favourable clinical outcome of noac use ...202032676673
functional and regulatory characterization of three amts in maize roots.maize grows in nitrate-dominated dryland soils, but shortly upon localized dressing of nitrogen fertilizers, ammonium is retained as a noticeable form of nitrogen source available to roots. thus in addition to nitrate, the absorption of ammonium can be an important strategy that promotes rapid plant growth at strong nitrogen demanding stages. the present study reports the functional characterization of three root-expressed ammonium transporters (amts), aiming at finding out functional and regula ...202032676086
mechanosensitivity is an essential component of phototransduction in vertebrate rods.photoreceptors are specialized cells devoted to the transduction of the incoming visual signals. rods are able also to shed from their tip old disks and to synthesize at the base of the outer segment (os) new disks. by combining electrophysiology, optical tweezers (ots), and biochemistry, we investigate mechanosensitivity in the rods of xenopus laevis, and we show that 1) mechanosensitive channels (mscs), transient receptor potential canonical 1 (trpc1), and piezo1 are present in rod inner segme ...202032667916
role of taalmt1 malate-gaba transporter in alkaline ph tolerance of wheat.malate exudation through wheat (triticum aestivum l) aluminium-activated malate transporter 1 (taalmt1) confers al3+ tolerance at low ph, but is also activated by alkaline ph, and is regulated by and facilitates significant transport of gamma-aminobutyric acid (gaba, a zwitterionic buffer). therefore, taalmt1 may facilitate acidification of an alkaline rhizosphere by promoting exudation of both malate and gaba. here, the performance of wheat near isogenic lines et8 (al+3 -tolerant, high taalmt1 ...202032666573
uncoupling sodium channel dimers restores the phenotype of a pain-linked nav 1.7 channel mutation.the voltage-gated sodium channel nav 1.7 is essential for adequate perception of painful stimuli. mutations in the encoding gene, scn9a, cause various pain syndromes in humans. the hnav 1.7/a1632e channel mutant causes symptoms of erythromelalgia and paroxysmal extreme pain disorder (pepd), and its main gating change is a strongly enhanced persistent current. on the basis of recently published 3d structures of voltage-gated sodium channels, we investigated how the inactivation particle binds to ...202032663327
slc12a2 variants cause a neurodevelopmental disorder or cochleovestibular defect.the slc12 gene family consists of slc12a1-slc12a9, encoding electroneutral cation-coupled chloride co-transporters. scl12a2 has been shown to play a role in corticogenesis and therefore represents a strong candidate neurodevelopmental disorder gene. through trio exome sequencing we identified de novo mutations in slc12a2 in six children with neurodevelopmental disorders. all had developmental delay or intellectual disability ranging from mild to severe. two had sensorineural deafness. we also id ...202032658972
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