Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| the antidepressant bupropion is a negative allosteric modulator of serotonin type 3a receptors. | the fda-approved antidepressant and smoking cessation drug bupropion is known to inhibit dopamine and norepinephrine reuptake transporters, as well as nicotinic acetylcholine receptors (nachrs) which are cation-conducting members of the cys-loop superfamily of ion channels, and more broadly pentameric ligand-gated ion channels (plgics). in the present study, we examined the ability of bupropion and its primary metabolite hydroxybupropion to block the function of cation-selective serotonin type 3 ... | 2017 | 27671323 |
| the extracellular c-loop domain plays an important role in the cell adhesion function of aquaporin 0. | although aquaporin 0 (aqp0) is a member of the aqp family, it has limited water permeability compared with other members. aqp0 may also have cell adhesion-related functions, but the evidence is still limited. here, we studied the relationship of aqp0 to cell adhesion and determined the region required for cell adhesion. | 2017 | 27754715 |
| rhythm generation, coordination, and initiation in the vocal pathways of male african clawed frogs. | central pattern generators (cpgs) in the brain stem are considered to underlie vocalizations in many vertebrate species, but the detailed mechanisms underlying how motor rhythms are generated, coordinated, and initiated remain unclear. we addressed these issues using isolated brain preparations of xenopus laevis from which fictive vocalizations can be elicited. advertisement calls of male x. laevis that consist of fast and slow trills are generated by vocal cpgs contained in the brain stem. brai ... | 2017 | 27760822 |
| characterization of cadmium chloride-induced bip accumulation in xenopus laevis a6 kidney epithelial cells. | endoplasmic reticulum (er) stress can result in the accumulation of unfolded/misfolded protein in the er lumen, which can trigger the unfolded protein response (upr) resulting in the activation of various genes including immunoglobulin-binding protein (bip; also known as glucose-regulated protein 78 or hspa5). bip, an er heat shock protein 70 (hsp70) family member, binds to unfolded protein, inhibits their aggregation and re-folds them in an atp-dependent manner. while cadmium, an environmental ... | 2017 | 27746171 |
| a sister chromatid cohesion assay using xenopus egg extracts. | cell-free extracts made from xenopus laevis eggs enable us to recapitulate many chromosomal events associated with cell cycle progression in a test tube. when sperm chromatin is incubated with these extracts, it is first duplicated within an assembled nucleus, and is then transformed into mitotic chromosomes, in each of which sister chromatids are juxtaposed with each other in a cohesin-dependent manner. here we describe our protocols for assembling duplicated chromosomes using egg extracts, alo ... | 2017 | 27797070 |
| characterization of human short chain dehydrogenase/reductase sdr16c family members related to retinol dehydrogenase 10. | all-trans-retinoic acid (ra) is a bioactive derivative of vitamin a that serves as an activating ligand for nuclear transcription factors, retinoic acid receptors. ra biosynthesis is initiated by the enzymes that oxidize retinol to retinaldehyde. it is well established that retinol dehydrogenase 10 (rdh10, sdr16c4), which belongs to the 16c family of the short chain dehydrogenase/reductase (sdr) superfamily of proteins, is the major enzyme responsible for the oxidation of retinol to retinaldehyd ... | 2017 | 27793605 |
| methylmercury induces an initial increase in gaba-evoked currents in xenopus oocytes expressing α1 and α6 subunit-containing gabaa receptors. | early onset effects of methylmercury (mehg) on recombinant α1β2γ2s or α6β2γ2s subunit-containing gabaa receptors were examined. these are two of the most prevalent receptor types found in cerebellum-a consistent target of mehg-induced neurotoxicity. heterologously expressed receptors were used in order to: (1) isolate receptor-mediated events from extraneous effects of mehg due to stimulation of the receptor secondary to increased release of gaba seen with mehg in neurons in situ and (2) limit t ... | 2017 | 27720918 |
| tissue-specific selenium accumulation and toxicity in adult female xenopus laevis chronically exposed to elevated dietary selenomethionine. | selenium (se) is a developmental toxicant that is also capable of altering the bioenergetic and endocrine status of adult fish. to date, aquatic ecotoxicological research has predominantly focused on the toxic effects of se in fish, and minimal information has been published related to amphibians. the objective of the present study was to investigate the potential toxicity associated with chronically elevated dietary se consumption in adult female amphibians utilizing the model species xenopus l ... | 2017 | 27666932 |
| characterization of tilapia (oreochromis niloticus) aldehyde reductase (akr1a1) gene, promoter and expression pattern in benzo-a-pyrene exposed fish. | this study planned to isolation and characterization of akr1a1 cdna from bap injected nile tilapia (oreochromis niloticus), comparison of its characteristic structures with those of other species, characterization of akr1a1 gene and promoter, and investigation of akr1a1 mrna expression in various organs of bap injected tilapia. the cdna was 1172 bp long which includes an open reading frame of 975 bp encoding a 324 amino acids protein and a stop codon. the sequence showed 3' and 5' non-coding reg ... | 2017 | 27800707 |
| developmental changes in head movement kinematics during swimming in xenopus laevis tadpoles. | during the post-embryonic developmental growth of animals, a number of physiological parameters such as locomotor performance, dynamics and behavioural repertoire are adjusted to match the requirements determined by changes in body size, proportions and shape. moreover, changes in movement parameters also cause changes in the dynamics of self-generated sensory stimuli, to which motion-detecting sensory systems have to adapt. here, we examined head movements and swimming kinematics of xenopus lae ... | 2017 | 27811303 |
| cftr-β-catenin interaction regulates mouse embryonic stem cell differentiation and embryonic development. | cystic fibrosis transmembrane conductance regulator (cftr) is a camp-regulated anion channel capable of conducting both cl- and hco3-, mutations of which cause cystic fibrosis (cf), a common autosomal recessive disease. although cf patients are known to have varied degree of developmental problems, the biological role of cftr in embryonic development remains elusive. here, we show that cftr is functionally expressed in mouse escs. cftr-/- mescs exhibit dramatic defect in mesendoderm differentiat ... | 2017 | 27834953 |
| electrophysiological activity of a neurotoxic fraction from the venom of box jellyfish carybdea marsupialis. | carybdea marsupialis is a widely distributed box jellyfish found in the mediterranean and in the tropical waters of the caribbean sea. its venom is a complex mixture of biologically active compounds that are used to catch prey. in order to evaluate the activity of the neurotoxins in the venom, bioassays were carried out using the marine crab ocypode quadrata. the proteins with neurotoxic effect were partially purified using low-pressure liquid chromatography techniques. gel filtration (sephadex ... | 2017 | 27815048 |
| clustered xenopus keratin genes: a genomic, transcriptomic, and proteomic analysis. | keratin genes belong to the intermediate filament superfamily and their expression is altered following morphological and physiological changes in vertebrate epithelial cells. keratin genes are divided into two groups, type i and ii, and are clustered on vertebrate genomes, including those of xenopus species. various keratin genes have been identified and characterized by their unique expression patterns throughout ontogeny in xenopus laevis; however, compilation of previously reported and newly ... | 2017 | 27842699 |
| thyroid hormone-induced activation of notch signaling is required for adult intestinal stem cell development during xenopus laevis metamorphosis. | in xenopus laevis intestine during metamorphosis, the larval epithelial cells are removed by apoptosis, and the adult epithelial stem (ae) cells appear concomitantly. they proliferate and differentiate to form the adult epithelium (ep). thyroid hormone (th) is well established to trigger this remodeling by regulating the expression of various genes including notch receptor. to study the role of notch signaling, we have analyzed the expression of its components, including the ligands (dll and jag ... | 2017 | 27870267 |
| use of xenopus laevis oocytes to study auxin transport. | xenopus laevis oocytes are an expression system that is particularly well suited for the characterization of membrane transporters. oocytes possess only very little endogenous transport systems and therefore transporters can be studied with a high signal-to-noise ratio. this book chapter provides the basic methods to use xenopus oocytes for the characterization of transporters by radiotracer experiments. while the methods described here were established to study auxin transport they can easily b ... | 2017 | 27864772 |
| δβγ-enac is inhibited by cftr but stimulated by camp in xenopus laevis oocytes. | the epithelial sodium channel (enac) and the cystic fibrosis transmembrane conductance regulator (cftr) chloride channel critically regulate airway surface liquid by driving fluid absorption and secretion, respectively. their functional interplay is complex and incompletely understood. enac is a heteromeric channel with three well-characterized subunits (α, β, and γ). in humans, an additional δ-enac subunit exists in lung and several other tissues, where it may replace the α-subunit to form δβγ- ... | 2017 | 27941075 |
| nemo-like kinase 1 (nlk1) and paraxial protocadherin (papc) cooperatively control xenopus gastrulation through regulation of wnt/planar cell polarity (pcp) signaling. | the wnt/planar cell polarity (pcp) pathway directs cell migration during vertebrate gastrulation and is essential for proper embryonic development. paraxial protocadherin (papc, gene symbol pcdh8.2) is an important activator of wnt/pcp signaling during xenopus gastrulation, but how papc activity is controlled is incompletely understood. here we show that nemo-like kinase 1 (nlk1), an atypical mitogen-activated protein (map) kinase, physically associates with the c-terminus of papc. this interact ... | 2017 | 27875771 |
| reversible developmental stasis in response to nutrient availability in the xenopus laevis central nervous system. | many organisms confront intermittent nutrient restriction (nr), but the mechanisms to cope with nutrient fluctuations during development are not well understood. this is particularly true of the brain, the development and function of which is energy intensive. here we examine the effects of nutrient availability on visual system development in xenopus laevis tadpoles. during the first week of development, tadpoles draw nutrients from maternally provided yolk. upon yolk depletion, animals forage ... | 2017 | 27875263 |
| controlling the messenger: regulated translation of maternal mrnas in xenopus laevis development. | the selective translation of maternal mrnas encoding cell-fate determinants drives the earliest decisions of embryogenesis that establish the vertebrate body plan. this chapter will discuss studies in xenopus laevis that provide insights into mechanisms underlying this translational control. xenopus has been a powerful model organism for many discoveries relevant to the translational control of maternal mrnas because of the large size of its oocytes and eggs that allow for microinjection of mole ... | 2017 | 27975270 |
| primary brain calcification causal pit2 transport-knockout variants can exert dominant negative effects on wild-type pit2 transport function in mammalian cells. | primary brain calcification (pbc) is a neurodegenerative disorder characterized by calcium-phosphate deposits in the basal ganglia and often also other areas of the brain. the prevalent clinical manifestations are cognitive impairment, neuropsychiatric symptoms, and movement disorders. in recent years, monoallelic variants in slc20a2, which encodes the type iii sodium-dependent inorganic phosphate (pi) transporter 2 (pit2), have been linked to the familial form of pbc in 40-50% of the families r ... | 2017 | 27943094 |
| xenopus laevis neuronal cell adhesion molecule (nrcam): plasticity of a cam in the developing nervous system. | neuron-glial-related cell adhesion molecule (nrcam) is a neuronal cell adhesion molecule of the l1 immunoglobulin superfamily, which plays diverse roles during nervous system development including axon growth and guidance, synapse formation, and formation of the myelinated nerve. perturbations in nrcam function cause a wide variety of disorders, which can affect wiring and targeting of neurons, or cause psychiatric disorders as well as cancers through abnormal modulation of signaling events. in ... | 2017 | 27942869 |
| subfunctionalization of paralogous aryl hydrocarbon receptors from the frog xenopus laevis: distinct target genes and differential responses to specific agonists in a single cell type. | gene duplication confers genetic redundancy that can facilitate subfunctionalization, the partitioning of ancestral functions between paralogs. we capitalize on a recent genome duplication in xenopus laevis (african clawed frog) to interrogate possible functional differentiation between alloalleles of the aryl hydrocarbon receptor (ahr), a ligand-activated transcription factor that mediates toxicity of dioxin-like compounds and plays a role in the physiology and development of the cardiovascular ... | 2017 | 27994169 |
| retinoid-like compounds produced by phytoplankton affect embryonic development of xenopus laevis. | teratogenic effects, which were remarkably similar to those induced by retinoic acids, have been seen in wild frogs indicating possible source of retinoids in the environment. recent studies indicate that some cyanobacterial species can contain teratogenic retinoic acids (ras) and their analogues. retinoids are known to regulate important processes such as differentiation, development, and embryogenesis. the study investigated the effects of exudates (extracellular compounds) of two cyanobacteri ... | 2017 | 27992848 |
| bicarbonate sensing in mouse cortical astrocytes during extracellular acid/base disturbances. | the present study suggests that the electrogenic sodium-bicarbonate cotransporter, nbce1, supported by carbonic anhydrase ii, caii, provides an efficient mechanism of bicarbonate sensing in cortical astrocytes. this mechanism is proposed to play a major role in setting the phi responses to extracellular acid/base challenges in astrocytes. a decrease in extracellular [hco3- ] during isocapnic acidosis and isohydric hypocapnia, or an increase in intracellular [hco3- ] during hypercapnic acidosis, ... | 2017 | 27981578 |
| evaluation of a commercial electro-kinetically pumped sheath-flow nanospray interface coupled to an automated capillary zone electrophoresis system. | capillary zone electrophoresis-electrospray ionization-mass spectrometry (cze-esi-ms) is attracting renewed attention for proteomic and metabolomic analysis. an important reason for this interest is the maturation and commercialization of interfaces for coupling cze with esi-ms. one of these interfaces is an electro-kinetically pumped sheath flow nanospray interface developed by the dovichi group, in which a very low sheath flow is generated based on electroosmosis within a glass emitter. cmp sc ... | 2017 | 27981343 |
| expression profile of rrbp1 genes during embryonic development and in adult tissues of xenopus laevis. | recent studies suggest that ribosome-binding protein 1 (rrbp1) is involved in multiple diseases such as tumorigenesis and cardiomyopathies. however, its function during embryonic development remains largely unknown. we searched xenopus laevis database with human rrbp1 protein sequence and identified two cdna sequences encoding xenopus orthologs of rrbp1 including rrbp1a (nm_001089623) and rrbp1b (nm_001092468). both genes were firstly detected at blastula stage 8 with weak signals in animal hemi ... | 2017 | 28034797 |
| visual experience dependent regulation of neuronal structure and function by histone deacetylase 1 in developing xenopus tectum in vivo. | histone deacetylase 1 (hdac1) is thought to play pivotal roles in neurogenesis and neurodegeneration. however, the role of hdac1 in neuronal growth and structural plasticity in the developing brain in vivo remains unclear. here, we show that in the optic tectum of xenopus laevis, hdac1 knockdown dramatically decreased the frequency of ampar-mediated synaptic currents and increased the frequency of gabaar-mediated currents, whereas hdac1 overexpression significantly decreased the frequency of gab ... | 2017 | 28033671 |
| the amino acid transporter, slc1a3, is plasma membrane-localised in adipocytes and its activity is insensitive to insulin. | the hormone insulin coordinates the catabolism of nutrients by protein phosphorylation. phosphoproteomic analysis identified insulin-responsive phosphorylation of the glu/asp transporter slc1a3/eaat1 in adipocytes. the role of slc1a3 in adipocytes is not well-understood. we show that slc1a3 is localised to the plasma membrane and the major regulator of acidic amino acid uptake in adipocytes. however, its localisation and activity were unaffected by insulin or mutation of the insulin-regulated ph ... | 2017 | 28032905 |
| human neuronal calcium sensor-1 protein avoids histidine residues to decrease ph sensitivity. | ph is highly regulated in mammalian central nervous systems. neuronal calcium sensor-1 (ncs-1) can interact with numerous target proteins. compared to that in the ncs-1 protein of caenorhabditis elegans, evolution has avoided the placement of histidine residues at positions 102 and 83 in the ncs-1 protein of humans and xenopus laevis, possibly to decrease the conformational sensitivity to ph gradients in synaptic processes. we used all-atom molecular dynamics simulations to investigate the effec ... | 2017 | 28030949 |
| ape2 zf-grf facilitates 3'-5' resection of dna damage following oxidative stress. | the xenopus laevis ape2 (apurinic/apyrimidinic endonuclease 2) nuclease participates in 3'-5' nucleolytic resection of oxidative dna damage and activation of the atr-chk1 dna damage response (ddr) pathway via ill-defined mechanisms. here we report that ape2 resection activity is regulated by dna interactions in its zf-grf domain, a region sharing high homology with ddr proteins topoisomerase 3α (top3α) and neil3 (nei-like dna glycosylase 3), as well as transcription and rna regulatory proteins, ... | 2017 | 28028224 |
| evolution of vocal patterns: tuning hindbrain circuits during species divergence. | the neural circuits underlying divergent courtship behaviors of closely related species provide a framework for insight into the evolution of motor patterns. in frogs, male advertisement calls serve as unique species identifiers and females prefer conspecific to heterospecific calls. advertisement calls of three relatively recently (∼8.5 mya) diverged species - xenopus laevis, x. petersii and x. victorianus - include rapid trains of sound pulses (fast trills). we show that while fast trills are ... | 2017 | 28011819 |
| pfkfb4 control of akt signaling is essential for premigratory and migratory neural crest formation. | neural crest (nc) specification comprises an early phase, initiating immature nc progenitors formation at neural plate stage, and a later phase at neural fold stage, resulting in a functional premigratory nc that is able to delaminate and migrate. we found that the nc gene regulatory network triggers upregulation of pfkfb4 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4) during this late specification phase. as shown in previous studies, pfkfb4 controls akt signaling in gastrulas and gly ... | 2017 | 29038306 |
| sonic hedgehog antagonists reduce size and alter patterning of the frog inner ear. | sonic hedgehog (shh) signaling plays a major role in vertebrate development, from regulation of proliferation to the patterning of various organs. in amniotes, shh affects dorsoventral patterning in the inner ear but affects anteroposterior patterning in teleost ears. it remains unknown how altered function of shh relates to morphogenetic changes that coincide with the evolution of limbs and novel auditory organs in the ear. in this study, we used the tetrapod, xenopus laevis, to test how increa ... | 2017 | 29030893 |
| molecular cloning and functional expression of the k+ channel kv7.1 and the regulatory subunit kcne1 from equine myocardium. | the voltage-gated k+-channel kv7.1 and the subunit kcne1, encoded by the kcnq1 and kcne1 genes, respectively, are responsible for termination of the cardiac action potential. in humans, mutations in these genes can predispose patients to arrhythmias and sudden cardiac death (scd). | 2017 | 28917093 |
| organ culture of the xenopus tadpole intestine. | during xenopus metamorphosis, most tadpole organs remodel from the larval to adult form to prepare for adaptation to terrestrial life. organ culture serves as an important tool for studying larval-to-adult organ remodeling independent of the effects of other parts of the body. here, i introduce a protocol for organ culture in vitro using the xenopus laevis tadpole intestine before metamorphic climax. during culture in the absence of exogenous 3,3',5-triiodo-l-thyronine (t3), the most potent natu ... | 2017 | 28912375 |
| collagen-embedded tumor transplantations in xenopus laevis tadpoles. | the xenopus laevis tadpole provides a valuable model for studying tumorigenesis and tumor immunity by intravital real-time microscopy. using well-characterized thymic lymphoid tumor lines (15/0 and ff-2) that are transplantable into their compatible hosts (lg-15 isogenic clones and the f inbred strain, respectively), a system of semisolid tumor engraftment has been designed. because these lymphoid tumor cell lines are not adherent and grow in suspension, they are first immobilized in a matrix of ... | 2017 | 28912374 |
| regulatory remodeling in the allo-tetraploid frog xenopus laevis. | genome duplication has played a pivotal role in the evolution of many eukaryotic lineages, including the vertebrates. a relatively recent vertebrate genome duplication is that in xenopus laevis, which resulted from the hybridization of two closely related species about 17 million years ago. however, little is known about the consequences of this duplication at the level of the genome, the epigenome, and gene expression. | 2017 | 29065907 |
| metabolic comparison of dorsal versus ventral cells directly in the live 8-cell frog embryo by microprobe single-cell ce-esi-ms. | single-cell mass spectrometry (ms) empowers the characterization of metabolomic changes as cells differentiate to different tissues during early embryogenesis. using whole-cell dissection and capillary electrophoresis electrospray ionization (ce-esi) ms, we recently uncovered metabolic cell-to-cell differences in the 8- and 16-cell embryo of the south african clawed frog (xenopus laevis), raising the question whether metabolic cell heterogeneity is also detectable across the dorsal-ventral axis ... | 2017 | 29062391 |
| proton-independent activation of acid-sensing ion channel asic3 by alkaloid lindoldhamine from laurus nobilis. | acid-sensing ion channels (asics) play an important role in synaptic plasticity and learning, as well as in nociception and mechanosensation. asics are implicated in pain, neurological and psychiatric diseases but their therapeutic potential is limited by lack of ligands activating them at physiological ph. | 2017 | 29277899 |
| direct modification of the 5-ht3 receptor current by some anticancer drugs. | the serotonin (5-hydroxytryptamine) type 3 (5-ht3) receptor is an important target in the control of emesis, and 5-ht3 receptor antagonists are effective against the early phase chemotherapy evoked vomiting. we recently reported that the anticancer drugs irinotecan and topotecan directly modulate the 5-ht-mediated 5-ht3 receptor current in vitro. in addition, the drug response depends on the 5-ht3 subunit composition. here, we explored the effects of 35 anticancer drugs on the 5-ht3 receptor cur ... | 2017 | 29277715 |
| a comparison of electronic and traditional cigarette butt leachate on the development of xenopus laevis embryos. | potential developmental toxicities of three different cigarette butt leachates were evaluated using the frog embryo teratogenesis assay-xenopus (fetax). xenopus laevis embryos were exposed to regular cigarette butt (rcb), menthol (mcb) and electronic (ecb) in concentrations ranging from 0 to 4 butts/l for rcb and mcb and 0-10 butts/l for ecb. the embryos were from stage 8 to 11 and were exposed for a 96-h period in static renewal test conditions. median lethal concentration (lc50), malformation ... | 2017 | 28959628 |
| e-cigarette aerosol exposure can cause craniofacial defects in xenopus laevis embryos and mammalian neural crest cells. | since electronic cigarette (ecig) introduction to american markets in 2007, vaping has surged in popularity. many, including women of reproductive age, also believe that ecig use is safer than traditional tobacco cigarettes and is not hazardous when pregnant. however, there are few studies investigating the effects of ecig exposure on the developing embryo and nothing is known about potential effects on craniofacial development. therefore, we have tested the effects of several aerosolized e-ciga ... | 2017 | 28957438 |
| six1 and eya1 both promote and arrest neuronal differentiation by activating multiple notch pathway genes. | the transcription factor six1 and its cofactor eya1 are important regulators of neurogenesis in cranial placodes, activating genes promoting both a progenitor state, such as hes8, and neuronal differentiation, such as neurog1. here, we use gain and loss of function studies in xenopus laevis to elucidate how these genes function during placodal neurogenesis. we first establish that hes8 is activated by notch signaling and represses neurog1 and neuronal differentiation, indicating that it mediates ... | 2017 | 28947179 |
| mammalian odorant receptor tuning breadth persists across distinct odorant panels. | the molecular receptive range (mrr) of a mammalian odorant receptor (or) is the set of odorant structures that activate the or, while the distribution of these odorant structures across odor space is the tuning breadth of the or. variation in tuning breadth is thought to be an important property of ors, with the mrrs of these receptors varying from narrowly to broadly tuned. however, defining the tuning breadth of an or is a technical challenge. for practical reasons, a screening panel that broa ... | 2017 | 28945824 |
| tumor immunology viewed from alternative animal models-the xenopus story. | nonmammalian comparative animal models are important not only to gain fundamental evolutionary understanding of the complex interactions of tumors with the immune system, but also to better predict the applicability of novel immunotherapeutic approaches to humans. after reviewing recent advances in developing alternative models, we focus on the amphibian xenopus laevis and its usefulness in deciphering the perplexing roles of mhc class i-like molecules and innate (i)t cells in tumor immunity. | 2017 | 28944105 |
| the brain is required for normal muscle and nerve patterning during early xenopus development. | possible roles of brain-derived signals in the regulation of embryogenesis are unknown. here we use an amputation assay in xenopus laevis to show that absence of brain alters subsequent muscle and peripheral nerve patterning during early development. the muscle phenotype can be rescued by an antagonist of muscarinic acetylcholine receptors. the observed defects occur at considerable distances from the head, suggesting that the brain provides long-range cues for other tissue systems during develo ... | 2017 | 28943634 |
| identification of regions responsible for the function of the plant k+ channels kat1 and akt2 in saccharomyces cerevisiae and xenopus laevis oocytes. | the arabidopsis k+ channel kat1 complements in k+-limited medium the growth of the k+ uptake defective saccharomyces cerevisiae mutant strain cy162, while another k+ channel, akt2, does not. to gain insight into the structural basis for this difference, we constructed 12 recombinant chimeric channels from these two genes. when expressed in cy162, only three of these chimeras fully rescued the growth of cy162 under k+-limited conditions. we conclude that the transmembrane core region of kat1 is i ... | 2017 | 28933647 |
| the nitrate transporter family protein ljnpf8.6 controls the n-fixing nodule activity. | n-fixing nodules are new organs formed on legume roots as a result of the beneficial interaction with soil bacteria, rhizobia. the nodule functioning is still a poorly characterized step of the symbiotic interaction, as only a few of the genes induced in n-fixing nodules have been functionally characterized. we present here the characterization of a member of the lotus japonicus nitrate transporter1/peptide transporter family, ljnpf8.6 the phenotypic characterization carried out in independent l ... | 2017 | 28931627 |
| beyond mouse cancer models: three-dimensional human-relevant in vitro and non-mammalian in vivo models for photodynamic therapy. | the proper design of experiments is a critical step for each study in order to obtain reproducible and reliable data. taking into account constant competitiveness in the quickly developing biomedical sciences and the availability of sophisticated techniques, the choice and establishment of an experimental model system are essential for a successful research project. currently, various sophisticated in vitro and in vivo models are being designed and developed in order to replace the use of mammal ... | 2017 | 28927532 |
| expression and functional proteomic analyses of osteocytes from xenopus laevis tested under mechanical stress conditions: preliminary observations on an appropriate new animal model. | hitherto, the role of the osteocyte as transducer of mechanical stimuli into biological signals is far from settled. in this study, we used an appropriate model represented by the cortex of xenopus laevis long bone diaphysis lacking (unlike the mammalian one) of vascular structures and containing only osteocytes inside the bone matrix. these structural features allow any change of protein profile that might be observed upon different experimental conditions, such as bone adaptation to stress/mec ... | 2017 | 28925539 |
| β subunits control the effects of human kv4.3 potassium channel phosphorylation. | the transient outward k+ current, ito, activates early in the cardiac myocyte action potential, to begin repolarization. human ito is generated primarily by two kv4.3 potassium channel α subunit splice variants (kv4.3l and kv4.3s) that diverge only by a c-terminal, membrane-proximal, 19-residue stretch unique to kv4.3l. protein kinase c (pkc) phosphorylation of threonine 504 within the kv4.3l-specific 19-residues mediates α-adrenergic inhibition of ito in human heart. kv4.3 is regulated in human ... | 2017 | 28919864 |
| the first successful observation of in-cell nmr signals of dna and rna in living human cells. | in order to understand intracellular biological events, information on the structure, dynamics and interaction of proteins and nucleic acids in living cells is of crucial importance. in-cell nmr is a promising method to obtain this information. although nmr signals of proteins in human cells have been reported, those of nucleic acids were reported only in xenopus laevis oocytes, i.e., not in human cells. here, dna and rna were introduced into human cells by means of pore formation by bacterial t ... | 2017 | 29022027 |
| fanconi-anemia-associated mutations destabilize rad51 filaments and impair replication fork protection. | fanconi anemia (fa) is a genetic disorder characterized by a defect in dna interstrand crosslink (icl) repair, chromosomal instability, and a predisposition to cancer. recently, two rad51 mutations were reported to cause an fa-like phenotype. despite the tight association of fa/hr proteins with replication fork (rf) stabilization during normal replication, it remains unknown how fa-associated rad51 mutations affect replication beyond icl lesions. here, we report that these mutations fail to prot ... | 2017 | 29020621 |
| an inhibitor of thyroid hormone synthesis protects tail skin grafts transplanted to syngenic adult frogs. | tail regression in amphibian tadpoles during metamorphosis is one of the most dynamic morphological changes in animal development and is induced by thyroid hormone (th). it has been proposed that tail resorption is driven by immunological rejection in xenopus laevis, based on experimental evidence showing that larval skin grafts become atrophic on syngenic recipient adult frogs. this led to the hypothesis that tail regression is induced by an immunological rejection against larval skin-specific ... | 2017 | 28990472 |
| design of light-sensitive nmdars by genetically encoded photo-cross-linkers. | genetic code expansion exploiting unnatural amino acids (uaas) is a powerful technique to create novel protein function in vivo. here, we provide a protocol for the incorporation of two uv-sensitive crosslinking uaas into nmda receptors (nmdars), a type of glutamate-gated ion channels mediating fast synaptic transmission. through heterologous expression in xenopus laevis oocytes, we have identified light-sensitive nmdars of glun2b subtype by using the two-electrode voltage electrophysiology meas ... | 2017 | 28986874 |
| permeant-specific gating of connexin 30 hemichannels. | gap junctions confer interconnectivity of the cytoplasm in neighboring cells via docking of two connexons expressed in each of the adjacent membranes. undocked connexons, referred to as hemichannels, may open and connect the cytoplasm with the extracellular fluid. the hemichannel configuration of connexins (cxs) displays isoform-specific permeability profiles that are not directly determined by the size and charge of the permeant. to further explore ca2+-mediated gating and permeability features ... | 2017 | 28982982 |
| the effect of food properties on grasping and manipulation in the aquatic frog xenopus laevis. | the ability to grasp an object is fundamental from an evolutionary perspective. involved in many daily activities, grasping has been extensively studied in primates and other mammals. yet other groups of tetrapods, including anurans, have also evolved significant forelimb prehensile capacities that are often thought to have originated in an arboreal context. in addition, grasping is also observed in aquatic species. but how aquatic frogs use their forelimbs to capture and manipulate prey remains ... | 2017 | 28982969 |
| desynchronizing embryonic cell division waves reveals the robustness of xenopus laevis development. | the early xenopus laevis embryo is replete with dynamic spatial waves. one such wave, the cell division wave, emerges from the collective cell division timing of first tens and later hundreds of cells throughout the embryo. here, we show that cell division waves do not propagate between neighboring cells and do not rely on cell-to-cell coupling to maintain their division timing. instead, intrinsic variation in division period autonomously and gradually builds these striking patterns of cell divi ... | 2017 | 28978482 |
| the slc2a14 gene, encoding the novel glucose/dehydroascorbate transporter glut14, is associated with inflammatory bowel disease. | background: variations in intestinal antioxidant membrane transporters are implicated in the initiation and progression of inflammatory bowel disease (ibd). facilitated glucose transporter member 14 (glut14), encoded by the solute carrier family 2 member 14 (slc2a14) gene, is a putative transporter for dehydroascorbic acid and glucose. although information on the gene is limited, shorter and longer glut14 isoforms have been identified. we hypothesized that glut14 mediates glucose and dehydroasco ... | 2017 | 28971850 |
| differential cytolocation and functional assays of the two major human slc30a8 (znt8) isoforms. | the non-synonymous single nucleotide polymorphism (snp) rs13266634 in human zinc transporter 8, znt8 (slc30a8), leads to a r325 variant, which is associated with an increased risk of developing type 2 diabetes (t2d). although the molecular details remain unknown, the mutation is thought to alter the kinetics of zinc transport into insulin granules in pancreatic β-cells. nevertheless, analysis of znt8 sequences from several animals shows that the amino acid at position 325 is poorly conserved. ap ... | 2017 | 28965566 |
| reversal of ddk-mediated mcm phosphorylation by rif1-pp1 regulates replication initiation and replisome stability independently of atr/chk1. | dbf4-dependent kinases (ddks) are required for the initiation of dna replication, their essential targets being the mcm2-7 proteins. we show that, in xenopus laevis egg extracts and human cells, hyper-phosphorylation of dna-bound mcm4, but not phosphorylation of mcm2, correlates with dna replication. these phosphorylations are differentially affected by the ddk inhibitors pha-767491 and xl413. we show that ddk-dependent mcm phosphorylation is reversed by protein phosphatase 1 (pp1) targeted to c ... | 2017 | 28273463 |
| moving or being moved: that makes a difference. | during head/body movements, gaze stability is ensured by transformation of motion-related sensory signals into respective motor commands. passively induced motion in all vertebrates including amphibians evokes a robust vestibulo-ocular reflex, suggesting an equally important role of this motor reaction during actively induced motion. however, during self-induced movements including locomotion, motor efference copies offer a convenient additional substrate for counteracting retinal image displace ... | 2017 | 28271408 |
| structural analysis of the role of tpx2 in branching microtubule nucleation. | the mitotic spindle consists of microtubules (mts), which are nucleated by the γ-tubulin ring complex (γ-turc). how the γ-turc gets activated at the right time and location remains elusive. recently, it was uncovered that mts nucleate from preexisting mts within the mitotic spindle, which requires the protein tpx2, but the mechanism basis for tpx2 action is unknown. here, we investigate the role of tpx2 in branching mt nucleation. we establish the domain organization of xenopus laevis tpx2 and d ... | 2017 | 28264915 |
| gadolinium released by the linear gadolinium-based contrast-agent gd-dtpa decreases the activity of human epithelial na+ channels (enacs). | gadolinium-based-contrast-agents (gbcas) are used for magnetic-resonance-imaging and associated with renal and cardiovascular adverse reactions caused by released gd3+ ions. gd3+ is also a modulator of mechano-gated ion channels, including the epithelial na+ channel (enac) that is expressed in kidney epithelium and the vasculature. enac is important for salt-/water homeostasis and blood pressure regulation and a likely target of released gd3+ from gbcas causing the above-mentioned adverse reacti ... | 2017 | 28257815 |
| folate receptor 1 is necessary for neural plate cell apical constriction during xenopus neural tube formation. | folate supplementation prevents up to 70% of neural tube defects (ntds), which result from a failure of neural tube closure during embryogenesis. the elucidation of the mechanisms underlying folate action has been challenging. this study introduces xenopus laevis as a model to determine the cellular and molecular mechanisms involved in folate action during neural tube formation. we show that knockdown of folate receptor 1 (folr1; also known as frα) impairs neural tube formation and leads to ntds ... | 2017 | 28255006 |
| optimization of the t3-induced xenopus metamorphosis assay for detecting thyroid hormone signaling disruption of chemicals. | t3-induced xenopus metamorphosis is an ideal model for detecting thyroid hormone (th) signaling disruption of chemicals. to optimize the t3-induced xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for t3 induction. xenopus laevis at stage 52 were exposed to series of concentrations of t3 (0.31-2.5nmol/l) for 6days. by comparing morphological changes induced by t3 ... | 2017 | 28254053 |
| role of cdc6 during oogenesis and early embryo development in mouse and xenopus laevis. | cdc6 is an important player in cell cycle regulation. it is involved in the regulation of both s-phase and m-phase. its role during oogenesis is crucial for repression of the s-phase between the first and the second meiotic m-phases, and it also regulates, via cdk1 inhibition, the m-phase entry and exit. this is of special importance for the reactivation of the major m-phase-regulating kinase cdk1 (cyclin-dependent kinase 1) in oocytes entering metaphase ii of meiosis and in embryo cleavage divi ... | 2017 | 28247050 |
| kv3.1/kv3.2 channel positive modulators enable faster activating kinetics and increase firing frequency in fast-spiking gabaergic interneurons. | due to their fast kinetic properties, kv3.1 voltage gated potassium channels are important in setting and controlling firing frequency in neurons and pivotal in generating high frequency firing of interneurons. pharmacological activation of kv3.1 channels may possess therapeutic potential for treatment of epilepsy, hearing disorders, schizophrenia and cognitive impairments. here we thoroughly investigate the selectivity and positive modulation of the two small molecules, ex15 and re01, on kv3 ch ... | 2017 | 28242439 |
| the capz interacting protein rcsd1 is required for cardiogenesis downstream of wnt11a in xenopus laevis. | wnt proteins are critical for embryonic cardiogenesis and cardiomyogenesis by regulating different intracellular signalling pathways. whereas canonical wnt/β-catenin signalling is required for mesoderm induction and proliferation of cardiac progenitor cells, β-catenin independent, non-canonical wnt signalling regulates cardiac specification and terminal differentiation. although the diverse cardiac malformations associated with the loss of non-canonical wnt11 in mice such as outflow tract (oft) ... | 2017 | 28237811 |
| β subunits functionally differentiate human kv4.3 potassium channel splice variants. | the human ventricular cardiomyocyte transient outward k+ current (ito) mediates the initial phase of myocyte repolarization and its disruption is implicated in brugada syndrome and heart failure (hf). human cardiac ito is generated primarily by two kv4.3 splice variants (kv4.3l and kv4.3s, diverging only by a c-terminal, s6-proximal, 19-residue stretch unique to kv4.3l), which are differentially remodeled in hf, but considered functionally alike at baseline. kv4.3 is regulated in human heart by ... | 2017 | 28228734 |
| xenopus laevis kif18a is a highly processive kinesin required for meiotic spindle integrity. | the assembly and functionality of the mitotic spindle depends on the coordinated activities of microtubule-associated motor proteins of the dynein and kinesin superfamily. our current understanding of the function of motor proteins is significantly shaped by studies using xenopus laevis egg extract as its open structure allows complex experimental manipulations hardly feasible in other model systems. yet, the kinesin-8 orthologue of human kif18a has not been described in xenopus laevis so far. h ... | 2017 | 28228376 |
| acute and chronic outcomes of gas-bubble disease in a colony of african clawed frogs (xenopus laevis). | gas-bubble disease occurs in aquatic species that are exposed to water that is supersaturated with gases. in february 2007, municipal water supersaturated with gas was inadvertently pumped into the vivarium's aquatic housing systems and affected approximately 450 adult female xenopus laevis. the inflow of supersaturated water was stopped immediately, the holding tanks aggressively aerated, and all experimental manipulations and feeding ceased. within the first 6 h after the event, morbidity appr ... | 2017 | 28222834 |
| systematic variation of the benzenesulfonamide part of the glun2a selective nmda receptor antagonist tcn-201. | glun2a subunit containing n-methyl-d-aspartate receptors (nmdars) are highly involved in various physiological processes in the central nervous system, but also in some diseases, such as anxiety, depression and schizophrenia. however, the role of glun2a subunit containing nmdars in pathological processes is not exactly elucidated. in order to obtain potent and selective inhibitors of glun2a subunit containing nmdars, the selective negative allosteric modulator 2 was systematically modified at th ... | 2017 | 28222314 |
| heteromeric slick/slack k+ channels show graded sensitivity to cell volume changes. | slick and slack high-conductance k+ channels are found in the cns, kidneys, pancreas, among other organs, where they play an important role in cell excitability as well as in ion transport processes. they are both activated by na+ and cl- but show a differential regulation by cell volume changes. slick has been shown to be regulated by cell volume changes, whereas slack is insensitive. α-subunits of these channels form homomeric as well as heteromeric channels. it is the aim of this work to expl ... | 2017 | 28222129 |
| motor neurons tune premotor activity in a vertebrate central pattern generator. | central patterns generators (cpgs) are neural circuits that drive rhythmic motor output without sensory feedback. vertebrate cpgs are generally believed to operate in a top-down manner in which premotor interneurons activate motor neurons that in turn drive muscles. in contrast, the frog (xenopus laevis) vocal cpg contains a functionally unexplored neuronal projection from the motor nucleus to the premotor nucleus, indicating a recurrent pathway that may contribute to rhythm generation. in this ... | 2017 | 28219984 |
| a mutation in the g-protein gene gnb2 causes familial sinus node and atrioventricular conduction dysfunction. | familial sinus node and atrioventricular conduction dysfunction is a rare disorder that leads to paroxysmal dizziness, fatigue, and syncope because of a temporarily or permanently reduced heart rate. to date, only a few genes for familial sinus and atrioventricular conduction dysfunction are known, and the majority of cases remain pathogenically unresolved. | 2017 | 28219978 |
| disrupting effects of azocyclotin to the hypothalamo-pituitary-gonadal axis and reproduction of xenopus laevis. | over the past few decades, the hazards associated with the extensive use of organictin compounds have become an issue of extreme concern, while at present the effects of these substances on amphibians remain poorly understood. in the present study, we chose azocyclotin, one of common use acaricides in china. we focused on sexual development and steroidogenesis disrupting effects of azocyclotin in the xenopus laevis. tadpoles were exposed to azocyclotin (0.05 and 0.5μg/l) for long-term (4 months) ... | 2017 | 28213302 |
| the microtubule plus-end-tracking protein tacc3 promotes persistent axon outgrowth and mediates responses to axon guidance signals during development. | formation of precise neuronal connections requires proper axon guidance. microtubules (mts) of the growth cone provide a critical driving force during navigation of the growing ends of axons. pioneer mts and their plus-end tracking proteins (+tips) are thought to play integrative roles during this navigation. tacc3 is a + tip that we have previously implicated in regulating mt dynamics within axons. however, the role of tacc3 in axon guidance has not been previously explored. | 2017 | 28202041 |
| dynamic properties of calcium-activated chloride currents in xenopus laevis oocytes. | chloride is the most abundant permeable anion in the cell, and numerous studies in the last two decades highlight the great importance and broad physiological role of chloride currents mediated anion transport. they participate in a multiplicity of key processes, as for instance, the regulation of electrical excitability, apoptosis, cell cycle, epithelial secretion and neuronal excitability. in addition, dysfunction of cl- channels is involved in a variety of human diseases such as epilepsy, ost ... | 2017 | 28198817 |
| strong signal increase in sted fluorescence microscopy by imaging regions of subdiffraction extent. | photobleaching remains a limiting factor in superresolution fluorescence microscopy. this is particularly true for stimulated emission depletion (sted) and reversible saturable/switchable optical fluorescence transitions (resolft) microscopy, where adjacent fluorescent molecules are distinguished by sequentially turning them off (or on) using a pattern of light formed as a doughnut or a standing wave. in sample regions where the pattern intensity reaches or exceeds a certain threshold, the molec ... | 2017 | 28193881 |
| bile acids potentiate proton-activated currents in xenopus laevis oocytes expressing human acid-sensing ion channel (asic1a). | acid-sensing ion channels (asics) are nonvoltage-gated sodium channels transiently activated by extracellular protons and belong to the epithelial sodium channel (enac)/degenerin (deg) family of ion channels. bile acids have been shown to activate two members of this family, the bile acid-sensitive ion channel (basic) and enac. to investigate whether bile acids also modulate asic function, human asic1a was heterologously expressed in xenopus laevis oocytes. exposing oocytes to tauro-conjugated c ... | 2017 | 28193786 |
| filaggrin has evolved from an "s100 fused-type protein" (sftp) gene present in a common ancestor of amphibians and mammals. | the expression of filaggrin in differentiated keratinocytes and the association of filaggrin mutations with ichthyosis vulgaris and atopic dermatitis suggest that this prototypical member of the s100 fused-type protein (sftp) family plays a key role in the epidermal barrier to the environment. here, we report that sftp genes are present not only in amniotes but also in amphibians. four sftps are expressed in the skin of the frog xenopus laevis. the results of this study indicate that filaggrin h ... | 2017 | 28191671 |
| zebrafish transgenic constructs label specific neurons in xenopus laevis spinal cord and identify frog v0v spinal neurons. | a correctly functioning spinal cord is crucial for locomotion and communication between body and brain but there are fundamental gaps in our knowledge of how spinal neuronal circuitry is established and functions. to understand the genetic program that regulates specification and functions of this circuitry, we need to connect neuronal molecular phenotypes with physiological analyses. studies using xenopus laevis tadpoles have increased our understanding of spinal cord neuronal physiology and fu ... | 2017 | 28188691 |
| identification of a mammalian silicon transporter. | silicon (si) has long been known to play a major physiological and structural role in certain organisms, including diatoms, sponges, and many higher plants, leading to the recent identification of multiple proteins responsible for si transport in a range of algal and plant species. in mammals, despite several convincing studies suggesting that silicon is an important factor in bone development and connective tissue health, there is a critical lack of understanding about the biochemical pathways ... | 2017 | 28179233 |
| pax2/pax8-defined subdomains and the occurrence of apoptosis in the posterior placodal area of mice. | the present work aims to improve our understanding of the causes and functions of apoptosis during the morphogenesis of epibranchial placodes in mice. schematic maps helped to compare the spatiotemporal sequence of apoptotic events with the protein expression patterns of general (six1) and specific placodal markers (pax2, pax8). our findings challenge the view that, in mammals, all three epibranchial placodes spring from the original posterior placodal area (ppa) of presomite or early somite emb ... | 2017 | 28160066 |
| capillary electrophoresis coupled to negative mode electrospray ionization-mass spectrometry using an electrokinetically-pumped nanospray interface with primary amines grafted to the interior of a glass emitter. | we demonstrate an electrokinetically pumped sheath flow nanospray interface for capillary electrophoresis coupled to negative mode electrospray mass spectrometry. in this interface, application of an electric field generates electro-osmotic flow at the interior of a glass emitter that is pulled to a 10-20µm inner diameter orifice. electro-osmotic flow pumps liquid around the distal tip of the separation capillary, ensheathing analyte into the electrospray electrolyte. in negative ion mode, negat ... | 2017 | 28153293 |
| mir-182 regulates slit2-mediated axon guidance by modulating the local translation of a specific mrna. | during brain wiring, cue-induced axon behaviors such as directional steering and branching are aided by localized mrna translation. different guidance cues elicit translation of subsets of mrnas that differentially regulate the cytoskeleton, yet little is understood about how specific mrnas are selected for translation. micrornas (mirnas) are critical translational regulators that act through a sequence-specific mechanism. here, we investigate the local role of mirnas in mrna-specific translatio ... | 2017 | 28147273 |
| pharmacological characterization of the excitatory 'cys-loop' gaba receptor family in caenorhabditis elegans. | ionotropic gaba receptors are evolutionarily conserved proteins that mediate cellular and network inhibition in both vertebrates and invertebrates. a unique class of excitatory gaba receptors has been identified in several nematode species. despite well-characterized functions in caenorhabditis elegans, little is known about the pharmacology of the excitatory gaba receptors exp-1 and lgc-35. using a panel of compounds that differentially activate and modulate ionotropic gaba receptors, we invest ... | 2017 | 28146602 |
| extracellular ca2+ is required for fertilization in the african clawed frog, xenopus laevis. | the necessity of extracellular ca2+ for fertilization and early embryonic development in the african clawed frog, xenopus laevis, is controversial. ca2+ entry into x. laevis sperm is reportedly required for the acrosome reaction, yet fertilization and embryonic development have been documented to occur in high concentrations of the ca2+ chelator bapta. here we sought to resolve this controversy. | 2017 | 28114360 |
| molecular features of the l-type amino acid transporter 2 determine different import and export profiles for thyroid hormones and amino acids. | the l-type amino acid transporter 2 (lat2) imports amino acids (aa) and also certain thyroid hormones (th), e.g. 3,3'-t2 and t3, but not rt3 and t4. we utilized lat2 mutations (y130a, n133s, f242w) that increase 3,3'-t2 import and focus here on import and export capacity for aa, t4, t3, bch and derivatives thereof to delineate molecular features. transport studies and analysis of competitive inhibition of import by radiolabelled th and aa were performed in xenopus laevis oocytes. only y130a, a p ... | 2017 | 28108384 |
| diclofenac can exhibit estrogenic modes of action in male xenopus laevis, and affects the hypothalamus-pituitary-gonad axis and mating vocalizations. | diclofenac (dcf) is a non-steroidal analgesic and antiphlogistic. due to its tremendous use, dcf can be found in the environment, especially in sewage, but also surface waters, ground and drinking water. previous studies indicated that dcf can modulate the reproductive physiology of fish by altering the expression of important key enzymes of the hypothalamus-pituitary-gonad-axis (hpg-axis) and might act as an estrogenic endocrine disrupting chemical (edc). other studies, however, demonstrated th ... | 2017 | 28107717 |
| the nedd4 binding protein 3 is required for anterior neural development in xenopus laevis. | the fezzin family member nedd4-binding protein 3 (n4bp3) is known to regulate axonal and dendritic branching. here, we show that n4bp3 is expressed in the neural tissue of the early xenopus laevis embryo including the eye, the brain and neural crest cells. knockdown of n4bp3 in the xenopus anterior neural tissue results in severe developmental impairment of the eye, the brain and neural crest derived cranial cartilage structures. moreover, we demonstrate that n4bp3 depletion leads to a significa ... | 2017 | 28104388 |
| spinal cord regeneration in xenopus laevis. | here we present a protocol for the husbandry of xenopus laevis tadpoles and froglets, and procedures to study spinal cord regeneration. this includes methods to induce spinal cord injury (sci); dna and morpholino electroporation for genetic studies; in vivo imaging for cell analysis; a swimming test to measure functional recovery; and a convenient model for screening for new compounds that promote neural regeneration. these protocols establish x. laevis as a unique model organism for understandi ... | 2017 | 28102835 |
| automated mitotic spindle tracking suggests a link between spindle dynamics, spindle orientation, and anaphase onset in epithelial cells. | proper spindle positioning at anaphase onset is essential for normal tissue organization and function. here we develop automated spindle-tracking software and apply it to characterize mitotic spindle dynamics in the xenopus laevis embryonic epithelium. we find that metaphase spindles first undergo a sustained rotation that brings them on-axis with their final orientation. this sustained rotation is followed by a set of striking stereotyped rotational oscillations that bring the spindle into near ... | 2017 | 28100633 |
| scaling of pattern formations and morphogen gradients. | the concentration gradient of morphogens provides positional information for an embryo and plays a pivotal role in pattern formation of tissues during the developmental processes. morphogen-dependent pattern formations show robustness despite various perturbations. although tissues usually grow and dynamically change their size during histogenesis, proper patterns are formed without the influence of size variations. furthermore, even when the blastula embryo of xenopus laevis is bisected into do ... | 2017 | 28097650 |
| high-throughput analysis reveals novel maternal germline rnas crucial for primordial germ cell preservation and proper migration. | during oogenesis, hundreds of maternal rnas are selectively localized to the animal or vegetal pole, including determinants of somatic and germline fates. although microarray analysis has identified localized determinants, it is not comprehensive and is limited to known transcripts. here, we utilized high-throughput rna-sequencing analysis to comprehensively interrogate animal and vegetal pole rnas in the fully grown xenopus laevis oocyte. we identified 411 (198 annotated) and 27 (15 annotated) ... | 2017 | 28096217 |
| xenopus as a model for studies in mechanical stress and cell division. | we exist in a physical world, and cells within biological tissues must respond appropriately to both environmental forces and forces generated within the tissue to ensure normal development and homeostasis. cell division is required for normal tissue growth and maintenance, but both the direction and rate of cell division must be tightly controlled to avoid diseases of over-proliferation such as cancer. recent studies have shown that mechanical cues can cause mitotic entry and orient the mitotic ... | 2017 | 28095623 |
| tools for live imaging of active rho gtpases in xenopus. | rho family gtpases are signaling molecules that orchestrate cytoskeletal dynamics in a variety of cellular processes. because they effect localized changes to the cytoskeleton only in their active (gtp-bound) conformation, the ability to monitor the active state of rho gtpases in space and time is critical for understanding their function. here, we summarize popular tools used for live imaging of active rho gtpases, outlining advantages and drawbacks of these approaches. additionally, we highlig ... | 2017 | 28095620 |
| xenopus egg extract to study regulation of genome-wide and locus-specific dna replication. | faithful dna replication, coupled with accurate repair of dna damage, is essential to maintain genome stability and relies on different dna metabolism genes. many of these genes are involved in the assembly of replication origins, in the coordination of dna repair to protect replication forks progression in the presence of dna damage and in the replication of repetitive chromatin regions. some dna metabolism genes are essential in higher eukaryotes, suggesting the existence of specialized mechan ... | 2017 | 28095613 |
| xenopus laevis as a model system to study cytoskeletal dynamics during axon pathfinding. | the model system, xenopus laevis, has been used in innumerable research studies and has contributed to the understanding of multiple cytoskeletal components, including actin, microtubules, and neurofilaments, during axon pathfinding. xenopus developmental stages have been widely characterized, and the xenopus genome has been sequenced, allowing gene expression modifications through exogenous molecules. xenopus cell cultures are ideal for long periods of live imaging because they are easily obtai ... | 2017 | 28095612 |