Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| human cationic amino acid transporters are not affected by direct nitros(yl)ation. | a direct inhibiting effect of no on the function of cat-1 and -2a has been postulated to occur via nitrosylation of cysteine residues in the transporters. neither the no donor snap nor a mixture of sin-1 and spermine nonoate, that generates the strong nitrosating agent n2o3, reduced cat-mediated l-arginine transport. direct nitros(yl)ation does either not occur in cats or does not affect their transport function. a regulatory effect of no or nitrosating agents on cat-mediated transport under phy ... | 2020 | 32008093 |
| a novel calcium-activated potassium channel controls membrane potential and intracellular ph in trypanosoma cruzi. | trypanosoma cruzi develops in environments where nutrient availability, osmolarity, ionic concentrations, and ph undergo significant changes. the ability to adapt and respond to such conditions determines the survival and successful transmission of t. cruzi. ion channels play fundamental roles in controlling physiological parameters that ensure cell homeostasis by rapidly triggering compensatory mechanisms. combining molecular, cellular and electrophysiological approaches we have identified and ... | 2019 | 32010643 |
| annexin a3 is necessary for parallel artery-vein alignment in the mouse retina. | annexin a3 (anxa3) is a member of the calcium-regulated, cell membrane-binding family of annexin proteins. we previously confirmed that anxa3 is expressed in the endothelial lineage in vertebrates and that loss of anxa3 in xenopus laevis leads to embryonic blood vessel defects. however, the biological function of anxa3 in mammals is completely unknown. in order to investigate anxa3 vascular function in mammals, we generated an endothelial cell-specific anxa3 conditional knockout mouse model (anx ... | 2020 | 32020697 |
| bringing immersive science to undergraduate laboratory courses using crispr gene knockouts in frogs and butterflies. | the use of crispr/cas9 for gene editing offers new opportunities for biology students to perform genuine research exploring the gene-to-phenotype relationship. it is important to introduce the next generation of scientists, health practitioners and other members of society to the technical and ethical aspects of gene editing. here, we share our experience leading hands-on undergraduate laboratory classes, where students formulate hypotheses regarding the roles of candidate genes involved in deve ... | 2020 | 32034043 |
| antiarrhythmic properties of ranolazine: inhibition of atrial fibrillation associated task-1 potassium channels. | background: atrial fibrillation (af) is the most common sustained cardiac arrhythmia and one of the major causes of cardiovascular morbidity and mortality. despite good progress within the past years, safe and effective treatment of af remains an unmet clinical need. the anti-anginal agent ranolazine has been shown to exhibit antiarrhythmic properties via mainly late ina and ikr blockade. this results in prolongation of the atrial action potential duration (apd) and effective refractory period ( ... | 2019 | 32038227 |
| myelopoiesis of the amphibian xenopus laevis is segregated to the bone marrow, away from their hematopoietic peripheral liver. | across vertebrates, hematopoiesis takes place within designated tissues, wherein committed myeloid progenitors further differentiate toward cells with megakaryocyte/erythroid potential (mep) or those with granulocyte/macrophage potential (gmp). while the liver periphery (lp) of the xenopus laevis amphibian functions as a principal site of hematopoiesis and contains meps, cells with gmp potential are instead segregated to the bone marrow (bm) of this animal. presently, using gene expression and w ... | 2019 | 32038608 |
| low concentrations of tetrabromobisphenol a disrupt notch signaling and intestinal development in in vitro and in vivo models. | tetrabromobisphenol a (tbbpa) was recently reported to upregulate notch target gene expression in embryonic stem cells differentiating to neurons in vitro, implying activation on notch signaling, a crucial signaling involved in multiple organ development and homeostasis.the present study aimed to determine whether tbbpa at low concentrations can disrupt notch signaling in the intestine and subsequently its development using in vitro and in vivo models, given tbbpa uptake mainly via the intestine ... | 2020 | 32041402 |
| multistep peripherin-2/rds self-assembly drives membrane curvature for outer segment disk architecture and photoreceptor viability. | rod and cone photoreceptor outer segment (os) structural integrity is essential for normal vision; disruptions contribute to a broad variety of retinal ciliopathies. oss possess many hundreds of stacked membranous disks, which capture photons and scaffold the phototransduction cascade. although the molecular basis of os structure remains unresolved, recent studies suggest that the photoreceptor-specific tetraspanin, peripherin-2/rds (p/rds), may contribute to the highly curved rim domains at dis ... | 2020 | 32041874 |
| all-fibre supercontinuum laser for in vivo multispectral photoacoustic microscopy of lipids in the extended near-infrared region. | among the numerous endogenous biological molecules, information on lipids is highly coveted for understanding both aspects of developmental biology and research in fatal chronic diseases. due to the pronounced absorption features of lipids in the extended near-infrared region (1650-1850 nm), visualisation and identification of lipids become possible using multi-spectral photoacoustic (optoacoustic) microscopy. however, the spectroscopic studies in this spectral region require lasers that can pro ... | 2020 | 32042589 |
| the grapevine nae sodium exclusion locus encodes sodium transporters with diverse transport properties and localisation. | grapevine (vitis vinifera l.) is a valuable crop for human consumption and wine production, and is prone to suffering from salinity stress in arid regions or when exposed to low quality irrigation water. a previous study identified a quantitative trait locus (qtl) nae, containing six high-affinity potassium transporter 1 genes, that was associated with shoot na+ exclusion in grapevine. while hkt1;1 was predicted to be the most likely gene within this qtl to encode for this important salinity tol ... | 2020 | 32044673 |
| 2,2',4,4'-tetrabromodipheny ether (bde-47) disrupts gonadal development of the africa clawed frog (xenopus laevis). | previous studies have shown that bde-47, one of the most abundant polybrominated diphenyl ethers (pbdes) congeners, has a weak estrogenic activity, but it has remained unclear whether bde-47 disrupts gonadal development and causes male-to-female sex reversal in lower vertebrates, with limited and controversial data. the present study aimed to determine the effects of bde-47 on gonadal development in xenopus laevis, a model amphibian species for studying adverse effects of estrogenic chemicals on ... | 2020 | 32045789 |
| chlorpromazine binding to the pas domains uncovers the effect of ligand modulation on eag channel activity. | ether-a-go-go (eag) potassium selective channels are major regulators of neuronal excitability and cancer progression. eag channels contain a per-arnt-sim (pas) domain in their intracellular n-terminal region. the pas domain is structurally similar to the pas domains in non-ion channel proteins, where these domains frequently function as ligand-binding domains. despite the structural similarity, it is not known whether the pas domain can regulate eag channel function via ligand binding. here, us ... | 2020 | 32047112 |
| interactions of deet and novel repellents with mosquito odorant receptors. | the carboxamide n,n-di-ethyl-meta-toluamide (deet) is the most effective and widely used insect repellent today. however, drawbacks concerning the efficacy and the safety of the repellent have led to efforts to design new classes of insect repellents. through quantitative structure-activity relationships, chemists have discovered two chemical groups of novel repellents: the acylpiperidines and the carboxamides, with the acylpiperidines generally more potent in biological assays. although the exa ... | 2020 | 32048720 |
| ncbp2 modulates neurodevelopmental defects of the 3q29 deletion in drosophila and xenopus laevis models. | the 1.6 mbp deletion on chromosome 3q29 is associated with a range of neurodevelopmental disorders, including schizophrenia, autism, microcephaly, and intellectual disability. despite its importance towards neurodevelopment, the role of individual genes, genetic interactions, and disrupted biological mechanisms underlying the deletion have not been thoroughly characterized. here, we used quantitative methods to assay drosophila melanogaster and xenopus laevis models with tissue-specific individu ... | 2020 | 32053595 |
| ashwin gene expression profiles in oocytes, preimplantation embryos, and fetal and adult bovine tissues. | the ashwin gene, originally identified in xenopuslaevis, was found to be expressed first in the neural plate and later in the embryonic brain, eyes, and spinal cord. functional studies of ashwin suggest that it participates in cell survival and anteroposterior patterning. furthermore, ashwin is expressed zygotically in this species, which suggests that it participates in embryonic development. nevertheless, the expression of this gene has not been studied in mammals. thus, the aim of this study ... | 2020 | 32054057 |
| relationship between the induced iron overload model and hepatic erythropoiesis in xenopus laevis. | iron is an essential element for hemoglobin synthesis during erythropoiesis. iron overload, in contrast, adversely affects erythropoiesis and causes organ dysfunction. research using various animal models may help to elucidate pathophysiological mechanisms induced by excess iron. in the present study, we evaluated the relationship between iron metabolism and erythropoietic activity in the african clawed frog, xenopus laevis. in x. laevis, both erythropoiesis and iron metabolism occur in the live ... | 2020 | 32068375 |
| 14-3-3 targets keratin intermediate filaments to mechanically sensitive cell-cell contacts. | intermediate filament (if) cytoskeletal networks simultaneously support mechanical integrity and influence signal transduction pathways. marked remodeling of the keratin if network accompanies collective cellular morphogenetic movements that occur during early embryonic development in the frog xenopus laevis. while this reorganization of keratin is initiated by force transduction on cell-cell contacts mediated by c-cadherin, the mechanism by which keratin filament reorganization occurs remains p ... | 2020 | 32074004 |
| stem cell development involves divergent thyroid hormone receptor subtype expression and epigenetic modifications in the xenopus metamorphosing intestine. | in the intestine during metamorphosis of the frog xenopus laevis, most of the larval epithelial cells are induced to undergo apoptosis by thyroid hormone (th), and under continued th action, the remaining epithelial cells dedifferentiate into stem cells (scs), which then newly generate an adult epithelium analogous to the mammalian intestinal epithelium. previously, we have shown that the precursors of the scs that exist in the larval epithelium as differentiated absorptive cells specifically ex ... | 2020 | 32084349 |
| microtubule minus-end binding protein camsap2 and kinesin-14 motor kifc3 control dendritic microtubule organization. | neuronal dendrites are characterized by an anti-parallel microtubule organization. the mixed oriented microtubules promote dendrite development and facilitate polarized cargo trafficking; however, the mechanism that regulates dendritic microtubule organization is still unclear. here, we found that the kinesin-14 motor kifc3 is important for organizing dendritic microtubules and to control dendrite development. the kinesin-14 motor proteins (drosophila melanogaster ncd, saccharomyces cerevisiae k ... | 2020 | 32084403 |
| discovery of the arp2 protein as a determining molecule in tumor cell death. | cancer is a multifactorial disease that constitutes a serious public health problem worldwide. prostate cancer advanced stages are associated with the development of androgen-independent tumors and an apoptosis-resistant phenotype that progresses to metastasis. by studying androgen-independent lymphoid nodule carcinoma of the prostate (lncap) cells induced to apoptosis by serum elimination, we identified the activation of a non-selective cationic channel of 23ps conductance that promotes incomin ... | 2019 | 32091029 |
| regeneration enhancers: a clue to reactivation of developmental genes. | during tissue and organ regeneration, cells initially detect damage and then alter nuclear transcription in favor of tissue/organ reconstruction. until recently, studies of tissue regeneration have focused on the identification of relevant genes. these studies show that many developmental genes are reused during regeneration. concurrently, comparative genomics studies have shown that the total number of genes does not vastly differ among vertebrate taxa. moreover, functional analyses of developm ... | 2020 | 32096563 |
| chromatin accessibility and histone acetylation in the regulation of competence in early development. | as development proceeds, inductive cues are interpreted by competent tissues in a spatially and temporally restricted manner. while key inductive signaling pathways within competent cells are well-described at a molecular level, the mechanisms by which tissues lose responsiveness to inductive signals are not well understood. localized activation of wnt signaling before zygotic gene activation in xenopus laevis leads to dorsal development, but competence to induce dorsal genes in response to wnts ... | 2020 | 32119833 |
| activation of mouse nbce1-b by xenopus laevis and mouse irbits: role of the variable nt appendage of irbits. | the ip3 receptor binding protein released with inositol 1,4,5-trisphosphate (irbit) plays important roles in the regulation of intracellular ca2+ signaling and intracellular ph. the mammals express two irbit paralogs, i.e., irbit1 (encoded by ahcyl1) and irbit2 (encoded by ahcyl2). the clawed frog xenopus laevis oocyte is widely used for biophysical studies on ion channels and transporters. it remains unknown whether endogenous irbit is expressed in xenopus oocytes. here, we cloned from frog ooc ... | 2020 | 32119862 |
| miniaturized filter-aided sample preparation (micro-fasp) method for high throughput, ultrasensitive proteomics sample preparation reveals proteome asymmetry in xenopus laevis embryos. | we report a miniaturized filter aided sample preparation method (micro-fasp) for low-loss preparation of submicrogram proteomic samples. the method employs a filter with ∼0.1 mm2 surface area, reduces the total volume of reagents to <10 μl, and requires only two sample transfer steps. the method was used to generate 25 883 unique peptides and 3069 protein groups from 1000 mcf-7 cells (∼100 ng protein content), and 13 367 peptides and 1895 protein groups were identified from 100 mcf-7 cells (∼10 ... | 2020 | 32125139 |
| hplc reveals novel features of nucleoside and nucleobase homeostasis, nucleoside metabolism and nucleoside transport. | humans possess three members of the cation-coupled concentrative nucleoside transporter cnt (slc 28) family, hcnt1-3: hcnt1 is selective for pyrimidine nucleosides but also transports adenosine, hcnt2 transports purine nucleosides and uridine, and hcnt3 transports both pyrimidine and purine nucleosides. hcnt1/2 transport nucleosides using the transmembrane na+ electrochemical gradient, while hcnt3 is both na+- and h+-coupled. by producing recombinant hcnt3 in xenopus laevis oocytes, we have used ... | 2020 | 32126230 |
| modeling bainbridge-ropers syndrome in xenopus laevis embryos. | the additional sex combs-like (asxl1-3) genes are linked to human neurodevelopmental disorders. the de novo truncating variants in asxl1-3 proteins serve as the genetic basis for severe neurodevelopmental diseases such as bohring-opitz, shashi-pena, and bainbridge-ropers syndromes, respectively. the phenotypes of these syndromes are similar but not identical, and include dramatic craniofacial defects, microcephaly, developmental delay, and severe intellectual disability, with a loss of speech an ... | 2020 | 32132929 |
| recent progress of in-cell nmr of nucleic acids in living human cells. | the inside of living cells is highly crowded with biological macromolecules. it has long been considered that the properties of nucleic acids and proteins, such as their structures, dynamics, interactions, and enzymatic activities, in intracellular environments are different from those under in vitro dilute conditions. in-cell nmr is a robust and powerful method used in the direct measurement of those properties in living cells. however, until 2 years ago, in-cell nmr was limited to xenopus laev ... | 2020 | 32144741 |
| testing for thyroid hormone disruptors, a review of non-mammalian in vivo models. | thyroid hormones (ths) play critical roles in profound changes in many vertebrates, notably in mammalian neurodevelopment, although the precise molecular mechanisms of these fundamental biological processes are still being unravelled. environmental and health concerns prompted the development of chemical safety testing and, in the context of endocrine disruption, identification of thyroid hormone axis disrupting chemicals (thadcs) remains particularly challenging. as various molecules are known ... | 2020 | 32147522 |
| quantitative capillary zone electrophoresis-mass spectrometry reveals the n-glycome developmental plan during vertebrate embryogenesis. | glycans are known to be involved in many biological processes, while little is known about the expression of n-glycans during vertebrate development. we now report the first quantitative studies of both the expression of n-linked glycans at six early development stages and the expression of n-glycosylated peptides at two early development stages in xenopus laevis, the african clawed frog. n-glycans were labeled with isobaric tandem mass tags, pooled, separated by capillary electrophoresis, and c ... | 2020 | 32149324 |
| xenopus laevis fgf16 activates the expression of genes coding for the transcription factors sp5 and sp5l. | fibroblast growth factors (fgfs) comprise a family of signalling molecules with essential roles in early embryonic development across animal species. the role of fgfs in mesoderm formation and patterning in xenopus has been particularly well studied. however, little is known about fgf16 in xenopus. using in situ hybridisation, we uncover the expression pattern of fgf16 during early xenopus laevis development, which has not been previously described. we show that the zygotic expression of fgf16 i ... | 2019 | 32149373 |
| fluorescent calcium imaging and subsequent in situ hybridization for neuronal precursor characterization in xenopus laevis. | spontaneous intracellular calcium activity can be observed in a variety of cell types and is proposed to play critical roles in a variety of physiological processes. in particular, appropriate regulation of calcium activity patterns during embryogenesis is necessary for many aspects of vertebrate neural development, including proper neural tube closure, synaptogenesis, and neurotransmitter phenotype specification. while the observation that calcium activity patterns can differ in both frequency ... | 2020 | 32150168 |
| reversible thiol oxidation inhibits the mitochondrial atp synthase in xenopus laevis oocytes. | oocytes are postulated to repress the proton pumps (e.g., complex iv) and atp synthase to safeguard mitochondrial dna homoplasmy by curtailing superoxide production. whether the atp synthase is inhibited is, however, unknown. here we show that: oligomycin sensitive atp synthase activity is significantly greater (~170 vs. 20 nmol/min-1/mg-1) in testes compared to oocytes in xenopus laevis (x. laevis). since atp synthase activity is redox regulated, we explored a regulatory role for reversible thi ... | 2020 | 32150908 |
| rapid shifts in the temperature dependence of locomotor performance in an invasive frog, xenopus laevis, implications for conservation. | temperature is a critical abiotic factor impacting all aspects of the biology of organisms, especially in ectotherms. as such, it is an important determinant of the potential invasive ability of organisms and may limit population expansion unless organisms can physiologically respond to changes in temperature either through plasticity or by adapting to their novel environment. here, we studied the african clawed frog, xenopus laevis, which has become invasive on a global scale. we compared adult ... | 2020 | 32159752 |
| amphibian thalamic nuclear organization during larval development and in the adult frog xenopus laevis: genoarchitecture and hodological analysis. | the early patterning of the thalamus during embryonic development defines rostral and caudal progenitor domains, which are conserved from fishes to mammals. however, the subsequent developmental mechanisms that lead to the adult thalamic configuration have only been investigated for mammals and other amniotes. in this study, we have analyzed in the anuran amphibian xenopus laevis (an anamniote vertebrate), through larval and postmetamorphic development, the progressive regional expression of spe ... | 2020 | 32162311 |
| von willebrand factor d and egf domains is an evolutionarily conserved and required feature of blastemas capable of multitissue appendage regeneration. | regenerative ability varies tremendously across species. a common feature of regeneration of appendages such as limbs, fins, antlers, and tails is the formation of a blastema-a transient structure that houses a pool of progenitor cells that can regenerate the missing tissue. we have identified the expression of von willebrand factor d and egf domains (vwde) as a common feature of blastemas capable of regenerating limbs and fins in a variety of highly regenerative species, including axolotl (amby ... | 2020 | 32163674 |
| evaluation of effective and practical euthanasia methods for larval african clawed frogs (xenopus laevis). | larval, or tadpole-stage xenopus laevis frogs are a popular research model for developmental biology and disease studies. existing euthanasia guidance documents offer recommendations for both eggs and adult stages, yet do not specifically address the larval stage. data evaluating effective euthanasia methods for groups of x. laevis tadpoles would therefore be useful. the goal of the current study was to evaluate the efficacy of various immersion euthanasia procedures on tadpoles: tricaine methan ... | 2020 | 32164797 |
| ssrp1-mediated histone h1 eviction promotes replication origin assembly and accelerated development. | in several metazoans, the number of active replication origins in embryonic nuclei is higher than in somatic ones, ensuring rapid genome duplication during synchronous embryonic cell divisions. high replication origin density can be restored by somatic nuclear reprogramming. however, mechanisms underlying high replication origin density formation coupled to rapid cell cycles are poorly understood. here, using xenopus laevis, we show that ssrp1 stimulates replication origin assembly on somatic ch ... | 2020 | 32165637 |
| targeted pathway-based in vivo testing using thyroperoxidase inhibition to evaluate plasma thyroxine as a surrogate metric of metamorphic success in model amphibian xenopus laevis. | chemical safety evaluation is in the midst of a transition from traditional whole-animal toxicity testing to molecular pathway-based in vitro assays and in silico modeling. however, to facilitate the shift in reliance on apical effects for risk assessment to predictive surrogate metrics having characterized linkages to chemical mechanisms of action, targeted in vivo testing is necessary to establish these predictive relationships. in this study, we demonstrate a means to predict thyroid-related ... | 2020 | 32176285 |
| mechanical stress regulates epithelial tissue integrity and stiffness through the fgfr/erk2 signaling pathway during embryogenesis. | physical forces generated by tissue-tissue interactions are a critical component of embryogenesis, aiding the formation of organs in a coordinated manner. in this study, using xenopus laevis embryos and phosphoproteome analyses, we uncover the rapid activation of the mitogen-activated protein (map) kinase erk2 upon stimulation with centrifugal, compression, or stretching force. we demonstrate that erk2 induces the remodeling of cytoskeletal proteins, including f-actin, an embryonic cadherin c-ca ... | 2020 | 32187556 |
| the actin-family protein arp4 is a novel suppressor for the formation and functions of nuclear f-actin. | the crosstalk between actin and actin-related proteins (arps), namely arp2 and arp3, plays a central role in facilitating actin polymerization in the cytoplasm and also in the nucleus. nuclear f-actin is required for transcriptional regulation, double-strand break repair, and nuclear organization. the formation of nuclear f-actin is highly dynamic, suggesting the involvement of positive and negative regulators for nuclear actin polymerization. while actin assembly factors for nuclear f-actin hav ... | 2020 | 32204557 |
| action potentials in xenopus oocytes triggered by blue light. | voltage-gated sodium (na+) channels are responsible for the fast upstroke of the action potential of excitable cells. the different α subunits of na+ channels respond to brief membrane depolarizations above a threshold level by undergoing conformational changes that result in the opening of the pore and a subsequent inward flux of na+. physiologically, these initial membrane depolarizations are caused by other ion channels that are activated by a variety of stimuli such as mechanical stretch, te ... | 2020 | 32211871 |
| defining the specific pathogen-free state of xenopus using taqman assays. | colonies of valuable inbred and transgenic laboratory-reared xenopus frogs maintained for research constitute naïve populations of animals susceptible to some opportunistic infectious diseases. therefore, it is prudent to characterize any new animal acquisitions before introduction into an existing colony as a biosecurity measure to preclude the concurrent introduction of an infectious microorganism associated with the new animal(s). in addition, some pathogens of xenopus, such as chlamydia and ... | 2020 | 32213545 |
| effect assessment of reclaimed water and carbamazepine exposure on the thyroid axis of x. laevis: apical and histological effects. | there is increasing environmental concern about the constant presence of pharmaceuticals and personal care products (ppcps) in surface water, generally attributed to water discharge from wastewater treatment plants (wwtps) that are unable to completely remove these compounds. the slight, but continuous, presence of these contaminants in reclaimed water (rw) poses a risk of chronic and sublethal toxicity, and the thyroid axis can likely be a target of many of these ppcps. in this work, we address ... | 2020 | 32220735 |
| effects of syntaxins 2, 3, and 4 on rat and human epithelial sodium channel (enac) in xenopus laevis oocytes. | syntaxins are snare proteins and may play a role in epithelial sodium channel (enac) trafficking. the aim of the present study was to investigate the effects of syntaxin 2 (stx2), syntaxin 3 (stx3), and syntaxin 4 (stx4) on rat (renac) and human enac (henac). co-expression of renac and stx3 or stx4 in xenopus laevis oocytes increased amiloride-sensitive whole-cell currents (δiami) on average by 50% and 135%, respectively, compared to oocytes expressing renac alone. in contrast, stx2 had no signi ... | 2020 | 32221667 |
| water-soluble variant of human lynx1 positively modulates synaptic plasticity and ameliorates cognitive impairment associated with α7-nachr dysfunction. | lynx1 is a gpi-tethered protein colocalized with nicotinic acetylcholine receptors (nachrs) in the brain areas important for learning and memory. previously, we demonstrated that at low micromolar concentrations the water-soluble lynx1 variant lacking gpi-anchor (ws-lynx1) acts on α7-nachrs as a positive allosteric modulator. we hypothesized that ws-lynx1 could be used for improvement of cognitive processes dependent on nachrs. here we showed that 2 µm ws-lynx1 increased the acetylcholine-evoked ... | 2020 | 32222974 |
| polyunsaturated fatty acid-derived iks channel activators shorten the qt interval ex-vivo and in-vivo. | we aimed to assess the ability of natural and modified polyunsaturated fatty acids (pufas) to shorten qt interval in ex-vivo and in-vivo guinea pig hearts. | 2020 | 32223014 |
| 4-hydroxynonenal induces cx46 hemichannel inhibition through its carbonylation. | hemichannels formed by connexins mediate the exchange of ions and signaling molecules between the cytoplasm and the extracellular milieu. under physiological conditions hemichannels have a low open probability, but in certain pathologies their open probability increases, which can result in cell damage. pathological conditions are characterized by the production of a number of proinflammatory molecules, including 4-hydroxynonenal (4-hne), one of the most common lipid peroxides produced in respon ... | 2020 | 32244060 |
| trefoil factor family (tff) modules are characteristic constituents of separate mucin complexes in the xenopus laevis integumentary mucus: in vitro binding studies with fim-a.1. | the skin of the frog xenopus laeevis is protected from microbial infections by a mucus barrier that contains frog integumentary mucins (fim)-a.1, fim-b.1, and fim-c.1. these gel-forming mucins are synthesized in mucous glands consisting of ordinary mucous cells and one or more cone cells at the gland base. fim-a.1 and fim-c.1 are unique because their cysteine-rich domains belong to the trefoil factor family (tff). furthermore, fim-a.1 is unusually short (about 400 amino acid residues). in contra ... | 2020 | 32244312 |
| αm-conotoxin miiij blocks nicotinic acetylcholine receptors at neuromuscular junctions of frog and fish. | we report the discovery and functional characterization of αm-conotoxin miiij, a peptide from the venom of the fish-hunting cone snail conus magus. injections of αm-miiij induced paralysis in goldfish (carassius auratus) but not mice. intracellular recording from skeletal muscles of fish (c. auratus) and frog (xenopus laevis) revealed that αm-miiij inhibited postsynaptic nicotinic acetylcholine receptors (nachrs) with an ic50 of ~0.1 μm. with comparable potency, αm-miiij reversibly blocked ach-g ... | 2020 | 32245200 |
| pact/prkra and p53 regulate transcriptional activity of dmrt1. | the transcription factor dmrt1 (doublesex and mab-3 related transcription factor) has two distinct functions, somatic-cell masculinization and germ-cell development in some vertebrate species, including mouse and the african clawed frog xenopus laevis. however, its transcriptional regulation remains unclear. we tried to identify dmrt1-interacting proteins from x. laevis testes by immunoprecipitation with an anti-dmrt1 antibody and ms/ms analysis, and selected three proteins, including pact/prkra ... | 2020 | 32251494 |
| natural size variation among embryos leads to the corresponding scaling in gene expression. | xenopus laevis frogs from laboratory stocks normally lay eggs exhibiting extensive size variability. we find that these initial size differences subsequently affect the size of the embryos prior to the onset of growth, and the size of tadpoles during the growth period. even though these tadpoles differ in size, their tissues, organs, and structures always seem to be properly proportioned, i.e. they display static allometry. initial axial patterning events in xenopus occur in a spherical embryo, ... | 2020 | 32259520 |
| microrna expression in the heart of xenopus laevis facilitates metabolic adaptation to dehydration. | xenopus laevis survive severe dehydration during the summer months in their natural range. microrna regulate translation of target mrnas and have shown to be differentially expressed in response to dehydration in x. laevis. during dehydration, heart rate is elevated which appears to compensate for the reduced oxygen delivery capability due to increased hematocrit. we hypothesized that micrornas would be differentially expressed in the heart to modulate gene expression levels in response to dehyd ... | 2020 | 32259572 |
| the tumor suppressor tff1 occurs in different forms and interacts with multiple partners in the human gastric mucus barrier: indications for diverse protective functions. | tff1 is a protective peptide of the trefoil factor family (tff), which is co-secreted with the mucin muc5ac, gastrokine 2 (gkn2), and igg fc binding protein (fcgbp) from gastric surface mucous cells. tff1-deficient mice obligatorily develop antropyloric adenoma and about 30% progress to carcinomas, indicating that tff1 is a tumor suppressor. as a hallmark, tff1 contains seven cysteine residues with three disulfide bonds stabilizing the conserved tff domain. here, we systematically investigated t ... | 2020 | 32260357 |
| isolation and characterization of a novel member of the acc ligand-gated chloride channel family, hco-lcg-46, from the parasitic nematode haemonchus contortus. | the acc-1 family of cys-loop receptors are ligand-gated chloride channels sensitive to acetylcholine (ach), and are only present in invertebrates. studies of this family of inhibitory receptors has provided insight into how they bind and respond to ach in a manner vastly different from nicotinic acetylcholine receptors and appear to be present in tissues that are relevant to anthelmintic action. here, we have identified two members of the acc-1 family from the parasitic nematode haemonchus conto ... | 2020 | 32268182 |
| nastep, an essential protein for self-incompatibility in nicotiana, performs a dual activity as a proteinase inhibitor and as a voltage-dependent channel blocker. | the s-specific pollen rejection response in nicotiana depends on the interaction between s-rnase and a suite of slf proteins. however, the biochemical pathway requires other essential proteins. one of them is the stigmatic protein nastep, which belongs to the kunitz-type protease inhibitor family. within the pollen tubes, nastep is a positive regulator of ht-b stability, likely inhibiting its degradation and, additionally, interacts with nasipp, a mitochondrial phosphate carrier. to gain a deepe ... | 2020 | 32272353 |
| toward the understanding of biology of oocyte life cycle in xenopus laevis: no oocytes left behind. | for the past more than 25 years, we have been focusing on the developmental and reproductive biology of the female gametes, oocytes, and eggs, of the african clawed frog xenopus laevis. | 2020 | 32273815 |
| simple embryo injection of long single-stranded donor templates with the crispr/cas9 system leads to homology-directed repair in xenopus tropicalis and xenopus laevis. | we report model experiments in which simple microinjection of fertilized eggs has been used to effectively perform homology-directed repair (hdr)-mediated gene editing in the two xenopus species used most frequently for research: x. tropicalis and x. laevis. we have used long single-stranded dnas having phosphorothioate modifications as donor templates for hdr at targeted genomic sites using the clustered regularly interspaced short palindromic repeats/crispr-associated protein 9 (crispr/cas9) s ... | 2020 | 32277804 |
| a generalizable optogenetic strategy to regulate receptor tyrosine kinases during vertebrate embryonic development. | ligand-independent activation of receptor tyrosine kinases (rtks) allows for dissecting out the receptor-specific signaling outcomes from the pleiotropic effects of the ligands. in this regard, rtk intracellular domains (icd) are of interest due to their ability to recapitulate signaling activity in a ligand-independent manner when fused to chemical or optical dimerizing domains. a common strategy for synthetic activation of rtks involves membrane tethering of dimerizer-rtk icd fusions. dependin ... | 2020 | 32277988 |
| multidirectional changes in parameters related to sulfur metabolism in frog tissues exposed to heavy metal-related stress. | the investigations showed changes of the cystathionine γ-lyase (cth), 3-mercaptopyruvate sulfurtransferase (mpst) and rhodanese (tst) activity and gene expression in the brain, heart, liver, kidney, skeletal muscles and testes in frogs pelophylaxridibundus, xenopuslaevis and xenopus tropicalis in response to pb2+, hg2+ and cd2+ stress. the results were analyzed jointly with changes in the expression of selected antioxidant enzymes (cytoplasmic and mitochondrial superoxide dismutase, glutathione ... | 2020 | 32283689 |
| neurotoxin merging: a strategy deployed by the venom of the spider cupiennius salei to potentiate toxicity on insects. | the venom of cupiennius salei is composed of dozens of neurotoxins, with most of them supposed to act on ion channels. some insecticidal monomeric neurotoxins contain an α-helical part besides their inhibitor cystine knot (ick) motif (type 1). other neurotoxins have, besides the ick motif, an α-helical part of an open loop, resulting in a heterodimeric structure (type 2). due to their low toxicity, it is difficult to understand the existence of type 2 peptides. here, we show with the voltage cla ... | 2020 | 32290562 |
| preparation of soluble malectin and its tetramer. | malectin is a membrane-anchored endoplasmic reticulum (er)-resident lectin, which is first identified in xenopus laevis in 2008 and highly conserved among animals. malectin plays an important role in the quality control of glycoprotein in the er through recognizing the glc2man9glcnac2 (g2m9) oligosaccharide chain on the newly synthesized glycoproteins. in this chapter, we will describe the preparation of recombinant soluble malectin and its tetramer, which might be developed as useful tools for ... | 2020 | 32306336 |
| effect of salinity acclimation on osmoregulation, oxidative stress, and metabolic enzymes in the invasive xenopus laevis. | aquatic animals often display physiological adjustments to improve their biological performance and hydrosaline balance in saline environments. in addition to energetic costs associated with osmoregulation, oxidative stress, and the activation of the antioxidant system are common cellular responses to salt stress in many species, but the knowledge of osmoregulation-linked oxidative homeostasis in amphibians is scarce. here we studied the biochemical responses and oxidative responses of xenopus l ... | 2020 | 32306529 |
| effects of bisphenol a and its alternative bisphenol f on notch signaling and intestinal development: a novel signaling by which bisphenols disrupt vertebrate development. | we previously found bisphenol a (bpa) alternative, bisphenol f (bpf) upregulated notch-related gene expression in intestines of the african clawed frog xenopus laevis, suggesting an agonistic action on notch signaling, a crucial signaling in multiple biological processes during development. here, we aimed to confirm the actions of bpa and bpf on notch signaling and to reveal their effects on intestinal development. using x. laevis, an excellent model for developmental biology, we found that 10-1 ... | 2020 | 32311622 |
| trpm6 and trpm7: novel players in cell intercalation during vertebrate embryonic development. | a common theme in organogenesis is how the final structure of organs emerge from epithelial tube structures, with the formation of the neural tube being one of the best examples. two types of cell movements co-occur during neural tube closure involving the migration of cells toward the midline of the embryo (mediolateral intercalation or convergent extension) as well as the deep movement of cells from inside the embryo to the outside of the lateral side of the neural plate (radial intercalation) ... | 2020 | 32315468 |
| spadin selectively antagonizes arachidonic acid activation of trek-1 channels. | trek-1 channel activity is a critical regulator of neuronal, cardiac, and smooth muscle physiology and pathology. the antidepressant peptide, spadin, has been proposed to be a trek-1-specific blocker. here we sought to examine the mechanism of action underlying spadin inhibition of trek-1 channels. heterologous expression in xenopus laevis oocytes and electrophysiological analysis using two-electrode voltage clamp in standard bath solutions was used to characterize the pharmacological profile of ... | 2020 | 32317978 |
| the abcf gene family facilitates disaggregation during animal development. | protein aggregation, once believed to be a harbinger and/or consequence of stress, age, and pathological conditions, is emerging as a novel concept in cellular regulation. normal versus pathological aggregation may be distinguished by the capacity of cells to regulate the formation, modification, and dissolution of aggregates. we find that caenorhabditis elegans aggregates are observed in large cells/blastomeres (oocytes, embryos) and in smaller, further differentiated cells (primordial germ cel ... | 2020 | 32320318 |
| transcriptional changes caused by estrogenic endocrine disrupting chemicals in gonad-mesonephros complexes of genetic male xenopus laevis: multiple biomarkers for early detection of testis differentiation disruption. | our recent study revealed some early molecular and cellular events in which 17β-estradiol (e2) disrupted testis differentiation and resulted in feminization in xenopus laevis (the african clawed frog), an ideal species for studying reproductive endocrine disruption by estrogenic endocrine disrupting chemicals (edcs). on this basis, we aimed to develop multiple biomarkers for early detection of testis differentiation disruption by estrogenic edcs in x. laevis. tadpoles at stage 45/46 were exposed ... | 2020 | 32335401 |
| concentration-dependent physiological and transcriptional adaptations of wheat seedlings to ammonium. | conventional wheat production utilizes fertilizers of various nitrogen forms. sole ammonium nutrition has been shown to improve grain quality, despite the potential toxic effects of ammonium at elevated concentrations. we therefore investigated the responses of young seedlings of winter wheat to different nitrogen sources (nh4 no3 = nn, nh4 cl = nnh4+ and kno3 = nno3- ). growth with ammonium-nitrate was superior. however, an elevated concentration of sole ammonium caused severe toxicity symptoms ... | 2020 | 32335941 |
| effect of nano-encapsulation of β-carotene on xenopus laevis embryos development (fetax). | vitamin a plays a vital role during embryo development as most precursor of embryonic retinoic acid, a key morphogen during embryogenesis. carotenoids, including β-carotene, are important vegetal source of vitamin a and in contrast to teratogenic potential of animal-derived retinoids, β-carotene is usually considered freed from embryotoxic effects and supplements in pregnancy with β-carotene are suggested. the aim of the present work is to evaluate the effect of bulk and nano-encapsulated β-caro ... | 2020 | 32346517 |
| how to grow xenopus laevis tadpole stages to adult. | in xenopus laevis, the tadpole stage is characterized by three forms-those occurring before the initiation of limb development, those covering limb development, and those encompassing metamorphosis. maximal tadpole growth, especially during the second form, is critically dependent on good husbandry practices. here we describe a protocol for raising xenopus laevis tadpoles through to adulthood. each step may need to be modified depending on the aquaria used and local conditions. | 2020 | 32350123 |
| structure of a single-chain h2a/h2b dimer. | chromatin is the complex assembly of nucleic acids and proteins that makes up the physiological form of the eukaryotic genome. the nucleosome is the fundamental repeating unit of chromatin, and is composed of ∼147 bp of dna wrapped around a histone octamer formed by two copies of each core histone: h2a, h2b, h3 and h4. prior to nucleosome assembly, and during histone eviction, histones are typically assembled into soluble h2a/h2b dimers and h3/h4 dimers and tetramers. a multitude of factors inte ... | 2020 | 32356520 |
| effects of ferrocenyl 4-(imino)-1,4-dihydro-quinolines on xenopus laevis prophase i - arrested oocytes: survival and hormonal-induced m-phase entry. | xenopus oocytes were used as cellular and molecular sentinels to assess the effects of a new class of organometallic compounds called ferrocenyl dihydroquinolines that have been developed as potential anti-cancer agents. one ferrocenyl dihydroquinoline compound exerted deleterious effects on oocyte survival after 48 h of incubation at 100 μm. two ferrocenyl dihydroquinoline compounds had an inhibitory effect on the resumption of progesterone induced oocyte meiosis, compared to controls without f ... | 2020 | 32357477 |
| inhibition of cardiac kv4.3 (ito) channel isoforms by class i antiarrhythmic drugs lidocaine and mexiletine. | transient outward k+ current, ito, contributes to cardiac action potential generation and is primarily carried by kv4.3 (kcnd3) channels. two kv4.3 isoforms are expressed in human ventricle and show differential remodeling in heart failure (hf). lidocaine and mexiletine may be applied in selected patients to suppress ventricular arrhythmias, without effects on sudden cardiac death or mortality. isoform-dependent effects of antiarrhythmic drugs on kv4.3 channels and potential implications for rem ... | 2020 | 32360350 |
| functional characterization of multifunctional ligands targeting acetylcholinesterase and alpha 7 nicotinic acetylcholine receptor. | alzheimer's disease (ad) is a neurodegenerative disorder associated with cholinergic dysfunction, provoking memory loss and cognitive dysfunction in elderly patients. the cholinergic hypothesis provided over the years with molecular targets for developing palliative treatments for ad, acting on the cholinergic system, namely, acetylcholinesterase and α7 nicotinic acetylcholine receptor (α7 nachr). in our synthetic work, we used "click-chemistry" to synthesize two multi target directed ligands (m ... | 2020 | 32360492 |
| combining endocannabinoids with retigabine for enhanced m-channel effect and improved kv7 subtype selectivity. | retigabine is unique among anticonvulsant drugs by targeting the neuronal m-channel, which is composed of kv7.2/kv7.3 and contributes to the negative neuronal resting membrane potential. unfortunately, retigabine causes adverse effects, which limits its clinical use. adverse effects may be reduced by developing m-channel activators with improved kv7 subtype selectivity. the aim of this study was to evaluate the prospect of endocannabinoids as m-channel activators, either in isolation or combined ... | 2020 | 32365171 |
| stentian structural plasticity in the developing visual system. | in a small fraction of xenopus tadpoles, a single retinal ganglion cell (rgc) axon misprojects to the ipsilateral optic tectum. presenting flashes of light to the ipsilateral eye causes that ipsilateral axon to fire, whereas stimulating the contralateral eye excites all other rgc inputs to the tectum. we performed time-lapse imaging of individual ipsilaterally projecting axons while stimulating either the ipsilateral or contralateral eye. stimulating either eye alone reduced axon elaboration by ... | 2020 | 32366647 |
| molecular architecture of the luminal ring of the xenopus laevis nuclear pore complex. | the nuclear pore complex (npc) mediates the flow of substances between the nucleus and cytoplasm in eukaryotic cells. here we report the cryo-electron tomography (cryo-et) structure of the luminal ring (lr) of the npc from xenopus laevis oocyte. the observed key structural features of the lr are independently confirmed by single-particle cryo-electron microscopy (cryo-em) analysis. the lr comprises eight butterfly-shaped subunits, each containing two symmetric wings. each wing consists of four e ... | 2020 | 32367042 |
| the gria3 c.2477g > a variant causes an exaggerated startle reflex, chorea, and multifocal myoclonus. | hemizygous mutations in gria3 encoding the glua3 subunit of the amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor are known to be associated with neurodevelopmental disorders, including intellectual disability, hypotonia, an autism spectrum disorder, sleep disturbances, and epilepsy in males. | 2020 | 32369665 |
| the mechanism of loop c-neonicotinoid interactions at insect nicotinic acetylcholine receptor α1 subunit predicts resistance emergence in pests. | neonicotinoids selectively modulate insect nicotinic acetylcholine receptors (insect nachrs). studies have shown that serine with ability to form a hydrogen bond in loop c of some insect nachr α subunits and glutamate with a negative charge at the corresponding position in vertebrate nachrs may contribute to enhancing and reducing the neonicotinoid actions, respectively. however, there is no clear evidence what loop c properties underpin the target site actions of neonicotinoids. thus, we have i ... | 2020 | 32371996 |
| molecular characterization of frog vocal neurons using constellation pharmacology. | identification and characterization of neuronal cell classes in motor circuits are essential for understanding the neural basis of behavior. it is a challenging task, especially in a non-genetic-model organism, to identify cell-specific expression of functional macromolecules. here, we performed constellation pharmacology, calcium imaging of dissociated neurons to pharmacologically identify functional receptors expressed by vocal neurons in adult male and female african clawed frogs, xenopus lae ... | 2020 | 32374212 |
| renal microvasculature in the adult pipid frog, xenopus laevis: a scanning electron microscope study of vascular corrosion casts. | we studied the opisthonephric (mesonephric) kidneys of adult male and female xenopus laevis using scanning electron microscopy (sem) of vascular corrosion casts and light microscopy of paraplast embedded tissue sections. both techniques displayed glomeruli from ventral to mid-dorsal regions of the kidneys with single glomeruli located dorsally close beneath the renal capsule. glomeruli in general were fed by a single afferent arteriole and drained via a single thinner efferent arteriole into per ... | 2020 | 32374496 |
| rpe cells engulf microvesicles secreted by degenerating rod photoreceptors. | rhodopsin is mislocalized to the inner segment plasma membrane (is pm) in various blinding disorders including autosomal-dominant retinitis pigmentosa caused by class i rhodopsin mutations. in these disorders, rhodopsin-laden microvesicles are secreted into the extracellular milieu by afflicted photoreceptor cells. using a xenopus laevis model expressing class i mutant rhodopsin or na+/k+-atpase (nka) fused to dendra2, we fluorescently labeled the microvesicles and found retinal pigment epitheli ... | 2020 | 32376599 |
| structure of the cytoplasmic ring of the xenopus laevis nuclear pore complex by cryo-electron microscopy single particle analysis. | the nuclear pore complex (npc) exhibits structural plasticity and has only been characterized at local resolutions of up to 15 å for the cytoplasmic ring (cr). here we present a single-particle cryo-electron microscopy (cryo-em) structure of the cr from xenopus laevis npc at average resolutions of 5.5-7.9 å, with local resolutions reaching 4.5 å. improved resolutions allow identification and placement of secondary structural elements in the majority of the cr components. the two y complexes in e ... | 2020 | 32376910 |
| differences in intrinsic tubulin dynamic properties contribute to spindle length control in xenopus species. | the function of cellular organelles relates not only to their molecular composition but also to their size. however, how the size of dynamic mesoscale structures is established and maintained remains poorly understood [1-3]. mitotic spindle length, for example, varies several-fold among cell types and among different organisms [4]. although most studies on spindle size control focus on changes in proteins that regulate microtubule dynamics [5-8], the contribution of the spindle's main building b ... | 2020 | 32386526 |
| managing the oocyte meiotic arrest-lessons from frogs and jellyfish. | during oocyte development, meiosis arrests in prophase of the first division for a remarkably prolonged period firstly during oocyte growth, and then when awaiting the appropriate hormonal signals for egg release. this prophase arrest is finally unlocked when locally produced maturation initiation hormones (mihs) trigger entry into m-phase. here, we assess the current knowledge of the successive cellular and molecular mechanisms responsible for keeping meiotic progression on hold. we focus on tw ... | 2020 | 32392797 |
| altered functional properties of a missense variant in the tresk k+ channel (kcnk18) associated with migraine and intellectual disability. | mutations in the kcnk18 gene that encodes the tresk k2p potassium channel have previously been linked with typical familial migraine with aura. recently, an atypical clinical case has been reported in which a male individual carrying the p.trp101arg (w101r) missense mutation in the kcnk18 gene was diagnosed with intellectual disability and migraine with brainstem aura. here we report the functional characterization of this new missense variant. this mutation is located in a highly conserved resi ... | 2020 | 32394190 |
| animal maintenance systems: xenopus laevis. | modular recirculating animal aquaculture systems incorporate uv sterilization and biological, mechanical, and activated carbon filtration, creating a nearly self-contained stable housing environment for xenopus laevis nonetheless, minimal water exchange is necessary to mitigate accumulation of metabolic waste, and regular weekly, monthly, and yearly maintenance is needed to ensure accurate and efficient operation. this protocol describes the methods for establishing a new recirculating system an ... | 2020 | 32404311 |
| supportive role of the na+ transporter cmhkt1;1 from cucumis melo in transgenic arabidopsis salt tolerance through improved k+/na+ balance. | cmhkt1;1 selectively exports na+ from plant cells. upon nacl stress, its expression increased in a salt-tolerant melon cultivar. overexpression of cmhkt1;1 increased transgenic arabidopsis salt tolerance through improved k+/na+ balance. high-affinity k+ transporters (hkts) are thought to be involved in reducing na+ in plant shoots under salt stress and modulating salt tolerance, but their function in a moderately salt-tolerant species of melon (cucumis melo l.) remains unclear. in this study, a ... | 2020 | 32405802 |
| imaging nascent transcription in wholemount vertebrate embryos to characterize zygotic genome activation. | a major event in early embryo development is the awakening of the embryonic genome, a process of large-scale transcriptional induction termed zygotic genome activation (zga). to understand how zga is controlled temporally and spatially, tools are required to image and quantify nascent transcription in wholemount embryos. in this chapter, we describe a metabolic labeling approach that leverages 5-ethynyl uridine (5-eu) incorporation into newly transcribed rnas. subsequently, click chemistry is us ... | 2020 | 32416911 |
| de novo mutations in fbrsl1 cause a novel recognizable malformation and intellectual disability syndrome. | we report truncating de novo variants in specific exons of fbrsl1 in three unrelated children with an overlapping syndromic phenotype with respiratory insufficiency, postnatal growth restriction, microcephaly, global developmental delay and other malformations. the function of fbrsl1 is largely unknown. interestingly, mutations in the fbrsl1 paralogue auts2 lead to an intellectual disability syndrome (auts2 syndrome). we determined human fbrsl1 transcripts and describe protein-coding forms by we ... | 2020 | 32424618 |
| identification of transient receptor potential channel 4-associated protein as a novel candidate gene causing congenital primary hypothyroidism. | congenital primary hypothyroidism (ch) is the most common endocrine disorder in neonates. | 2020 | 32428920 |
| cross-taxa distinctions in mechanisms of developmental effects for aquatic species exposed to trifluralin. | standard ecological risk assessment practices often rely on larval and juvenile fish toxicity data as representative of the amphibian aquatic phase. empirical evidence suggests that endpoints measured in fish early life stage tests are often sufficient to protect larval amphibians. however, the process of amphibian metamorphosis relies on endocrine cues that affect development and morphological restructuring and are not represented by these test endpoints. the present study compares developmenta ... | 2020 | 32445211 |
| optical control of muscular nicotinic channels with azocuroniums, photoswitchable azobenzenes bearing two n-methyl-n-carbocyclic quaternary ammonium groups. | by linking two n-methyl-n-carbocyclic quaternary ammonium groups to an azobenzene scaffold in meta- or para-positions we generated a series of photoswitchable neuromuscular ligands for which we coined the term "azocuroniums". these compounds switched between the (e)- and (z)-isomers by light irradiation at 400-450 nm and 335-340 nm, respectively. meta-azocuroniums were potent nicotinic ligands with a clear selectivity for the muscular nachrs compared to neuronal α7 and α4β2 subtypes, showed good ... | 2020 | 32447198 |
| modulation by neonicotinoids of honeybee α1/chicken β2 hybrid nicotinic acetylcholine receptors expressed in xenopus laevis oocytes. | neonicotinoids targeting insect nicotinic acetylcholine (ach) receptors (insect nachrs) are used for crop protection, but there is a concern about adverse effects on pollinators such as honeybees (apis mellifera). thus, we investigated the agonist actions of neonicotinoids (imidacloprid, thiacloprid and clothianidin) on a. mellifera α1 (amα1)/chicken β2 hybrid nachrs in xenopus laevis oocytes according to the subunit stoichiometry of (amα1)3(β2)2 and (amα1)2(β2)3 using voltage-clamp electrophysi ... | 2020 | 32448414 |
| microvascular anatomy of ovary and oviduct in the adult african clawed toad (xenopus laevis daudin, 1802)-histomorphology and scanning electron microscopy of vascular corrosion casts. | ovaries and oviducts of the adult african clawed toad (xenopus laevis daudin, 1802) were studied by light microscopy (lm) of paraplast embedded tissue sections and scanning electron microscopy (sem) of vascular corrosion casts (vccs). histomorphology revealed that ovarian vessels located in the thecal layers. ovarian and interlobar arteries displayed a horse-shoe shaped longitudinally running bundle of vascular smooth muscle cells. follicular blood vessels showed flattened profiles, which were c ... | 2020 | 32449214 |
| the regulation of akt and foxo transcription factors during dehydration in the african clawed frog (xenopus laevis). | the african clawed frog (xenopus laevis) naturally tolerates severe dehydration using biochemical adaptation, one of which is the elevation of antioxidant defenses during whole-body dehydration. the present study investigated the role and regulation of a pathway known to regulate oxidative stress response, the akt-foxo signaling pathway, in clawed frog skeletal muscle, responding to medium (15%) and high (30%) dehydration. protein levels of total and phosphorylated akt, foxo1, and foxo3 were ass ... | 2020 | 32451989 |
| nuclei determine the spatial origin of mitotic waves. | traveling waves play an essential role in coordinating mitosis over large distances, but what determines the spatial origin of mitotic waves remains unclear. here, we show that such waves initiate at pacemakers, regions that oscillate faster than their surroundings. in cell-free extracts of xenopus laevis eggs, we find that nuclei define such pacemakers by concentrating cell cycle regulators. in computational models of diffusively coupled oscillators that account for nuclear import, nuclear posi ... | 2020 | 32452767 |
| experimental platform using the amphibian xenopus laevis for research in fundamental and medical immunology. | the amphibian xenopus constitutes a powerful, versatile, and cost-effective nonmammalian model with which to investigate important contemporary issues of immunity relevant to human health such as ontogeny of immunity, self-tolerance, wound healing, autoimmunity, cancer immunity, immunotoxicology, and adaptation of host immune defenses to emerging pathogens. this model system presents several attractive features: an external developmental environment free of maternal influence that allows for eas ... | 2020 | 32457040 |
| cloning and expression of cockroach α7 nicotinic acetylcholine receptor subunit. | understanding insect nicotinic acetylcholine receptor (nachr) subtypes is of major interest because they are the main target of several insecticides. in this study, we have cloned a cockroach pameα7 subunit that encodes a 518 amino acid protein with futures typical of nachr subunit, and sequence homology to α7 subunit. pameα7 is differently expressed in the cockroach nervous system, in particular in the antennal lobes, optical lobes and the mushroom bodies where specific expression was found in ... | 2020 | 32457646 |
| association of a novel splice site mutation in p/q-type calcium channels with childhood epilepsy and late-onset slowly progressive non-episodic cerebellar ataxia. | episodic ataxia type 2 (ea2) is characterized by paroxysmal attacks of ataxia with typical onset in childhood or early adolescence. the disease is associated with mutations in the voltage-gated calcium channel alpha 1a subunit (cav2.1) that is encoded by the cacna1a gene. however, previously unrecognized atypical symptoms and the genetic overlap existing between ea2, spinocerebellar ataxia type 6, familial hemiplegic migraine type 1, and other neurological diseases blur the genotype/phenotype co ... | 2020 | 32471306 |