Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
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 ...202032335401
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 ...202032320318
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 ...202032317978
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 ...202032306529
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 ...202032306336
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 ...202032290562
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 ...202032283689
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 ...202032277988
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 ...202032277804
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.202032273815
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 ...202032272353
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 ...202032268182
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 ...202032260357
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 ...202032259572
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, ...202032259520
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 ...202032251494
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 ...202032245200
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 ...202032244312
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 ...202032244060
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 ...202032222974
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 ...202032221667
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 ...202032220735
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 ...202032213545
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 ...202032211871
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 ...202032204557
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 ...202032187556
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 ...202032176285
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 ...202032165637
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 ...202032164797
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 ...202032162311
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 ...202032159752
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 ...202032150908
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 ...202032150168
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 ...202032149324
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 ...202032147522
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 ...202032144741
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 ...202032125139
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 ...202032119862
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 ...202032119833
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 ...202032096563
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 ...202032084403
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 ...202032084349
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 ...202032074004
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 ...202032068375
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 ...202032054057
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 ...202032053595
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 ...202032048720
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 ...202032047112
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 ...202032045789
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 ...202032044673
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 ...202032042589
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 ...202032041874
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 ...202032041402
sorafenib activity and disposition in liver cancer does not depend on organic cation transporter 1.systemic therapy of advanced hepatocellular carcinoma (hcc) with the small-molecule multikinase inhibitor sorafenib is associated with large interindividual pharmacokinetic variability and unpredictable side effects potentially requiring dose reduction or treatment termination. organic cation transporter (oct1; gene slc22a1) has been proposed as a clinical biomarker of hcc response. because proof is lacking that oct1 transports sorafenib, we used a combinatorial approach to define how oct1 contr ...202031350763
ligand binding characteristics of the ku80 von willebrand domain.the n-terminal von willebrand domain of ku80 supports interactions with a ku binding motif (kbm) that has been identified in at least three other dna repair proteins: the non-homologous end joining (nhej) scaffold aplf, the modulator of retrovirus infection, mri, and the werner syndrome protein (wrn). a second, more recently identified ku binding motif present in xlf and several other proteins (kbmx) has also been reported to interact with this domain. the isolated ku80 von willebrand antigen do ...202031733588
pannexin 1 activation and inhibition is permeant-selective.the large-pore channel pannexin 1 (panx1) is expressed in many cell types and can open upon different, yet not fully established, stimuli. panx1 permeability is often inferred from channel permeability to fluorescent dyes, but it is currently unknown whether dye permeability translates to permeability to other molecules. cell shrinkage and c-terminal cleavage led to a panx1 open-state with increased permeability to atomic ions (current), but did not alter ethidium uptake. panx1 inhibitors affect ...202031698505
the hkt transporter hvhkt1;5 negatively regulates salt tolerance.maintaining low intracellular na+ concentrations is an essential physiological strategy in salt stress tolerance in most cereal crops. here, we characterized a member of the high-affinity k+ transporter (hkt) family in barley (hordeum vulgare), hvhkt1;5, which negatively regulates salt tolerance and has different functions from its homology in other cereal crops. hvhkt1;5 encodes a plasma membrane protein localized to root stele cells, particularly in xylem parenchyma cells adjacent to the xylem ...202031690708
simple method to characterize the ciliary proteome of multiciliated cells.motile cilia of multiciliated epithelial cells have important roles in animal development and cell homeostasis. although several studies have identified and reported proteins localized in this complex organelle and the related immotile primary cilia from various cell types, it is still challenging to isolate high quantities of ciliary proteins for proteomic analysis. in this study, african clawed frog (xenopus laevis) embryos, which have many multiciliated cells in the epidermis, were treated wi ...202031689115
complement c1q subunit molecules from xenopus laevis possess conserved function in c1q-immunoglobulin interaction.complement component 1q (c1q), together with c1r and c1s to form c1, recognize and bind immune complex to initiate the classical complement pathway. in this study, c1q subunit molecules (xlc1qa, xlc1qb, xlc1qc) were cloned and analyzed from xenopus laevis (x. laevis). the open reading frame (orf) of xlc1qa is 819 bp of nucleotide sequence encoding 272 amino acids, the orf of xlc1qb is 711 bp encoding 236 aa, and the xlc1qc is consists of 732 bp encoding 243 aa. the deduced amino acid sequences c ...202031678076
identification and characterization of the atlantic salmon peptide transporter 1a.peptide transporter 1 (pept1) mediates the uptake of dietary di-/tripeptides in vertebrates. however, in teleost fish gut, more than one pept1-type transporter might operate, because of teleost-specific whole gen(om)e duplication event(s) that occurred during evolution. here, we describe a novel teleost di-/tripeptide transporter, i.e., the atlantic salmon (salmo salar) peptide transporter 1a [pept1a; or solute carrier family 15 member 1a (slc15a1a)], which is a paralog (77% similarity and 64% i ...202031664857
extracellular lysine 38 plays a crucial role in ph-dependent transport via human monocarboxylate transporter 1.human monocarboxylate transporters (hmcts) are expressed in many tissues and mediate the transport of various substrates across the plasma membrane. among hmcts, hmct1-4 cotransport h+ with monocarboxylates such as pyruvate and l-lactate, implying that these proteins recognize both substrate and h+. however, the mechanism of translocation, and particularly that of hmct1 ph-dependent transport, remains largely unknown. this study aimed at identifying residues involved in the ph dependence of hmct ...202031593685
cytosolic gaba inhibits anion transport by wheat almt1.anion transport by aluminium-activated malate transporter (almt) proteins is negatively regulated by gamma-aminobutyric acid (gaba), which increases in concentration during stress. here, the interaction between gaba and wheat (triticum aestivum, ta) taalmt1 heterologously-expressed in xenopus laevis oocytes was investigated. gaba inhibited anion transport by taalmt1 in membrane patches from the cytosolic, not extracellular membrane face, via a reduction in open probability (npopen ), not an inhi ...202031591723
morpholino studies in xenopus brain development.antisense morpholino oligonucleotides (mos) have become a valuable method to knockdown protein levels, to block with mrna splicing and to interfere with mirna function. mos are widely used to alter gene expression in development of xenopus and zebrafish, where they are typically injected into the fertilized egg or blastomeres. here we present methods to use electroporation to target delivery of mos to the central nervous system of xenopus laevis or xenopus tropicalis tadpoles. briefly, mo electr ...202031552666
odontomas in frogs.odontomas are variably differentiated, hamartoma-like proliferations of odontogenic epithelium, pulp ectomesenchyme (odontoblasts), and dental matrix. frogs are polyphyodont and homodont. their teeth also differ from mammals in that they are restricted to the upper jaw in adults and lack a periodontal ligament and cementum, attaching directly to the underlying bone. odontomas were identified in an african clawed frog (xenopus laevis), a false tomato frog (dyscophus guineti), and a tomato frog of ...202031551010
the expression of key guidance genes at a forebrain axon turning point is maintained by distinct fgfr isoforms but a common downstream signal transduction mechanism.during development the axons of neurons grow toward and locate their synaptic partners to form functional neural circuits. axons do so by reading a map of guidance cues expressed by surrounding tissues. guidance cues are expressed at a precise space and time, but how guidance cue expression is regulated, and in a coordinated manner, is poorly understood. semaphorins (semas) and slits are families of molecular ligands that guide axons. we showed previously that fibroblast growth factor (fgf) sign ...202030993182
smooth muscle in cardiac chambers is common in turtles and extensive in the emydid turtle, trachemys scripta.a prominent layer of smooth muscle lining the luminal side of the atria of freshwater turtles (emydidae) was described more than a century ago. we recently demonstrated that this smooth muscle provides a previously unrecognized mechanism to change cardiac output in the emydid red-eared slider (trachemys scripta) that possibly contributes to their tremendous diving capacity. the purpose of the present immunohistochemical study was firstly to screen major groups of vertebrates for the presence of ...202031509333
coexposure to environmental concentrations of cis-bifenthrin and graphene oxide: adverse effects on the nervous system during metamorphic development of xenopus laevis.despite the great concerns associated with the combined biological effects of nanoparticles and insecticides, the current understanding of the corresponding ecological risks remains limited. xenopus laevis (x. laevis) tadpoles were exposed to various concentrations of typical pyrethroid (cis-bifenthrin; cis-bf), either alone or in combination with graphene oxide (go), for 21 days. the presence of go resulted in increased bioconcentration of cis-bf and a higher 1s-enantiomer fraction. exposure to ...202031425913
biochemical responses revealed in an amphibian species after exposure to a forgotten contaminant: an integrated biomarker assessment.vanadium is a metal whose toxicity towards terrestrial and aquatic species has been under-reported to date.. the biochemical responses of vanadium in amphibian species have not been determined. to establish the effects of vanadium (v) on exposed adult xenopus laevis, acute and chronic exposures were conducted, and biomarker analyses were performed on liver and muscle tissues from exposed frogs. biomarkers of exposure, such as acetylcholinesterase (ache) and metallothioneins (mt), were analysed. ...202031629886
lin28b increases neural crest cell migration and leads to transformation of trunk sympathoadrenal precursors.the rna-binding protein lin28b regulates developmental timing and determines stem cell identity by suppressing the let-7 family of micrornas. postembryonic reactivation of lin28b impairs cell commitment to differentiation, prompting their transformation. in this study, we assessed the extent to which ectopic lin28b expression modulates the physiological behavior of neural crest cells (ncc) and governs their transformation in the trunk region of developing embryos. we provide evidence that the ov ...202031601998
leishmania heme uptake involves lmflvcrb, a novel porphyrin transporter essential for the parasite.leishmaniasis comprises a group of neglected diseases caused by the protozoan parasite leishmania spp. as is the case for other trypanosomatid parasites, leishmania is auxotrophic for heme and must scavenge this essential compound from its human host. in mammals, the slc transporter flvcr2 mediates heme import across the plasma membrane. herein we identify and characterize leishmania major flvcrb (lmflvcrb), the first member of the flvcr family studied in a non-metazoan organism. this protein lo ...202031372684
adverse effects of fly ashes used as immobilizing agents for highly metal-contaminated soils on xenopus laevis oocytes survival and maturation-a study performed in the north of france with field soil extracts.amphibians are now recognized as the most endangered group. one of this decline causes is the degradation of their habitat through direct contamination of water, soil leaching, or runoff from surrounding contaminated soils and environments. in the north of france, the extensive industrial activities resulted in massive soil contamination by metal compounds. mineral amendments were added to soils to decrease trace metal mobility. because of the large areas to be treated, the use of inexpensive in ...202030875069
effects of glyphosate and a commercial formulation roundup® exposures on maturation of xenopus laevis oocytes.pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. while their populations are highly threatened with extinction. the aim of this work is to characterize the effects of glyphosate and its commercial formulation roundup® gt max on th ...202030835066
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
Refresh
firstprev
12345678910...
nextlast
Displaying items 101 - 200 of 17138