Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| conservatism and variability of gene expression profiles among homeologous transcription factors in xenopus laevis. | xenopus laevis has an allotetraploid genome of 3.1gb, in contrast to the diploid genome of a closely related species, xenopus tropicalis. here, we identified 412 genes (189 homeolog pairs, one homeologous gene cluster pair, and 28 singletons) encoding transcription factors (tfs) in the x. laevis genome by comparing them with their orthologs from x. tropicalis. those genes include the homeobox gene family (mix/bix, lhx, nkx, paired, pou, and vent), sox, fox, pax, dmrt, hes, gata, t-box, and some ... | 2017 | 27810169 |
| 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 |
| xenopus genomic data and browser resources. | the two species of xenopus most commonly used in biomedical research are the diploid xenopus (silurana) tropicalis and the tetraploid xenopus laevis. the x. tropicalis genome sequence has been available since 2010 and this year the x. laevis, genome from two distinct genetic backgrounds has been published. multiple genome assemblies available for both species and transcriptomic and epigenetic data sets are growing rapidly, all of which are available from a variety of web resources. this review d ... | 2017 | 27039265 |
| evaluating the teratogenicity of the selective ß3-adrenoceptor agonist, cl 316.243 hydrate by employing fetax (frog embryo teratogenesis assay). | in this study, the frog embryo teratogenesis assay (fetax - xenopus) technique was employed to evaluate the potential teratogenicity of the selective ß-adrenoceptor (ar) agonist, cl 316.243. in this context, cl 316.243 was applied to the south african clawed frog (xenopus laevis) embryos. the media containing the cl 316.24-exposed embryos were monitored and changed/replaced once every 24 hours. using fetax, we determined the minimum concentrations to inhibit growth (mcig) for cl 316.243. the 96- ... | 2017 | 27063898 |
| evaluation of microtransplantation of rat brain neurolemma into xenopus laevis oocytes as a technique to study the effect of neurotoxicants on endogenous voltage-sensitive ion channels. | microtransplantation of mammalian brain neurolemma into the plasma membrane of xenopus oocytes is used to study ion channels in their native form as they appear in the central nervous system. use of microtransplanted neurolemma is advantageous for various reasons: tissue can be obtained from various sources and at different developmental stages; ion channels and receptors are present in their native configuration in their proper lipid environment along with appropriate auxiliary subunits; allowi ... | 2017 | 27063102 |
| xenopus: leaping forward in kidney organogenesis. | while kidney donations stagnate, the number of people in need of kidney transplants continues to grow. although transplanting culture-grown organs is years away, pursuing the engineering of the kidney de novo is a valid means of closing the gap between the supply and demand of kidneys for transplantation. the structural organization of a mouse kidney is similar to that of humans. therefore, mice have traditionally served as the primary model system for the study of kidney development. the mouse ... | 2017 | 27099217 |
| gene expression analysis of developing cell groups in the pretectal region of xenopus laevis. | our previous analysis of progenitor domains in the pretectum of xenopus revealed three molecularly distinct anteroposterior subdivisions, identified as precommissural (pcp), juxtacommissural (jcp), and commissural (cop) histogenetic domains (morona et al. [2011] j comp neurol 519:1024-1050). here we analyzed at later developmental stages the nuclei derived from these areas, attending to their gene expression patterns and histogenesis. transcription-factor gene markers were used to selectively ma ... | 2017 | 27539385 |
| pharmacological characterization of histamine-gated chloride channels from the housefly musca domestica. | the biogenic amine histamine (ha) is not only the neurotransmitter of photoreceptors but also has important roles in mechanosensory reception, temperature preference, sleep and olfactory processing in insects. two cdnas (mdhcla and mdhclb) that encode ha-gated chloride channel subunits (mdhcla and mdhclb) were cloned from the housefly musca domestica. the crnas were injected into xenopus laevis oocytes to examine the functions and pharmacological characteristics of mdhcla and mdhclb channels usi ... | 2017 | 27139242 |
| expanding the genetic toolkit in xenopus: approaches and opportunities for human disease modeling. | the amphibian model xenopus, has been used extensively over the past century to study multiple aspects of cell and developmental biology. xenopus offers advantages of a non-mammalian system, including high fecundity, external development, and simple housing requirements, with additional advantages of large embryos, highly conserved developmental processes, and close evolutionary relationship to higher vertebrates. there are two main species of xenopus used in biomedical research, xenopus laevis ... | 2017 | 27109192 |
| expression pattern and pharmacological characterisation of two novel alternative splice variants of the glutamate-gated chloride channel in the small brown planthopper laodelphax striatellus. | glutamate-gated chloride channels (glucl) mediate fast inhibitory neurotransmission in invertebrate nervous systems. although only one glucl gene was presented in insects, it showed diverse alternative splicing that was speculated could affect channel function and pharmacology. | 2017 | 27302648 |
| in vitro models of cranial neural crest development toward toxicity tests: frog, mouse, and human. | during craniofacial development, cranial neural crest (nc)-derived mesenchymal cells migrate to pharyngeal arches and contribute extensively to neurons, schwann cells, smooth muscle cells, osteoblasts, chondrocytes, and odontoblasts, forming maxillofacial structures. in vitro models using model organism cells, such as african clawed frog (xenopus laevis) and mouse (mus musculus), were developed to understand cellular and molecular mechanisms of cranial nc development. recent studies using human ... | 2017 | 27299949 |
| sex chromosome differentiation and the w- and z-specific loci in xenopus laevis. | genetic sex-determining systems in vertebrates include two basic types of heterogamety; xx (female)/xy (male) and zz (male)/zw (female) types. the african clawed frog xenopus laevis has a zz/zw-type sex-determining system. in this species, we previously identified a w-specific sex (female)-determining gene dmw, and specified w and z chromosomes, which could be morphologically indistinguishable (homomorphic). in addition to dmw, we most recently discovered two genes, named scanw and ccdc69w, and ... | 2017 | 27297884 |
| genes coding for cyclin-dependent kinase inhibitors are fragile in xenopus. | cell proliferation is strictly regulated by the dosage balance among cell-cycle regulators such as cdk/cyclin complexes and cdk-inhibitors. even in the allotetraploid genome of xenopus laevis, the dosage balance must be maintained for animals to stay alive, and the duplicated homeologous genes seem to have gradually changed, through evolution, resulting in the best genes for them to thrive. in the xenopus laevis genome, while homeologous gene pairs of cdks are fundamentally maintained and a few ... | 2017 | 27393661 |
| generation of a xenopus laevis f1 albino j strain by genome editing and oocyte host-transfer. | completion of the xenopus laevis genome sequence from inbred j strain animals has facilitated the generation of germline mutant x. laevis using targeted genome editing. in the last few years, numerous reports have demonstrated that talens are able to induce mutations in f0 xenopus embryos, but none has demonstrated germline transmission of such mutations in x. laevis. in this report we used the oocyte host-transfer method to generate mutations in both tyrosinase homeologs and found highly-penetr ... | 2017 | 26993591 |
| genome-wide analysis of dorsal and ventral transcriptomes of the xenopus laevis gastrula. | rna sequencing has allowed high-throughput screening of differential gene expression in many tissues and organisms. xenopus laevis is a classical embryological and cell-free extract model system, but its genomic sequence had been lacking due to difficulties arising from allotetraploidy. there is currently much excitement surrounding the release of the completed x. laevis genome (version 9.1) by the joint genome institute (jgi), which provides a platform for genome-wide studies. here we present a ... | 2017 | 27016259 |
| the phosphoinositide sensitivity of the k(v) channel family. | recently, we screened several kv channels for possible dependence on plasma membrane phosphatidylinositol 4,5-bisphosphate (pi(4,5)p 2). the channels were expressed in tsa-201 cells and the pi(4,5)p 2 was depleted by several manipulations in whole-cell experiments with parallel measurements of channel activity. in contrast to reports on excised-patches using xenopus laevis oocytes, we found only kv 7, but none of the other tested kv channels, to be strongly dependent on pi(4,5)p 2. we now have e ... | 2017 | 23907203 |
| invasive american bullfrogs and african clawed frogs in south america: high suitability of occurrence in biodiversity hotspots. | fabiana g. barbosa, camila both, and miguel b. araújo (2017) invasion of protected areas by non-native species is currently one of the main threats to global biodiversity. using an ensemble of bioclimatic envelope models we quantify the degree of exposure of south american protected areas to invasion by two invasive amphibian species. we focus on protected areas that coincide with global biodiversity hotspots. the species modeled, lithobates catesbeianus and xenopus laevis, have been reported to ... | 2017 | 31966227 |
| molecular characterization and tissue expression profiles of prepro-vasoactive intestinal peptide in the chinese alligator (alligator sinensis) during the active and hibernating periods. | the chinese alligator (alligator sinensis), a freshwater crocodilian endemic to china, is one of the most endangered crocodilian species; up to this date, very little is known about the endocrine regulation of its metabolic activities during different physiological states. in this study, we characterized the structure of the prepro-vasoactive intestinal peptide in chinese alligator (prepro-cavip) for the first time and examined its expression profiles in various tissues during the active and hib ... | 2017 | 29356375 |
| functional variants in hcn4 and cacna1h may contribute to genetic generalized epilepsy. | genetic generalized epilepsy (gge) encompasses seizure disorders characterized by spike-and-wave discharges (swd) originating within thalamo-cortical circuits. hyperpolarization-activated (hcn) and t-type ca2+ channels are key modulators of rhythmic activity in these brain regions. here, we screened hcn4 and cacna1h genes for potentially contributory variants and provide their functional analysis. | 2017 | 29588962 |
| williams syndrome transcription factor is critical for neural crest cell function in xenopus laevis. | williams syndrome transcription factor (wstf) is one of ∼25 haplodeficient genes in patients with the complex developmental disorder williams syndrome (ws). ws results in visual/spatial processing defects, cognitive impairment, unique behavioral phenotypes, characteristic "elfin" facial features, low muscle tone and heart defects. wstf exists in several chromatin remodeling complexes and has roles in transcription, replication, and repair. chromatin remodeling is essential during embryogenesis, ... | 2017 | 22691402 |
| mustn1 is essential for craniofacial chondrogenesis during xenopus development. | mustn1 is a vertebrate-specific protein that, in vitro, was showed to be essential for prechondrocyte function and thus it has the potential to regulate chondrogenesis during embryonic development. we use xenopus laevis as a model to examine mustn1 involvement in chondrogenesis. previous work suggests that mustn1 is necessary but not sufficient for chondrogenic proliferation and differentiation, as well as myogenic differentiation in vitro. mustn1 was quantified and localized in developing xenop ... | 2017 | 22281807 |
| monepantel is a non-competitive antagonist of nicotinic acetylcholine receptors from ascaris suum and oesophagostomum dentatum. | zolvix®is a recently introduced anthelmintic drench containing monepantel as the active ingredient. monepantel is a positive allosteric modulator of deg-3/des-2 type nicotinic acetylcholine receptors (nachrs) in several nematode species. the drug has been reported to produce hypercontraction of caenorhabditis elegans and haemonchus contortus somatic muscle. we investigated the effects of monepantel on nachrs from ascaris suum and oesophagostomum dentatum heterologously expressed in xenopus laevi ... | 2017 | 29366967 |
| expression patterns of zebrafishnocturningenes and the transcriptional activity of the frognocturninpromoter in zebrafish rod photoreceptors. | daily modulation of gene expression is critical for the circadian rhythms of many organisms. one of the modulating mechanisms is based on nocturnin, a deadenylase that degrades mrna in a circadian fashion. thenocturningenes are expressed broadly, but their tissue expression patterns differ between mice and the frogxenopus laevis; this difference suggests that the extent of the regulation ofnocturingene expression varies among species. in this study, we set out to characterize the expression patt ... | 2017 | 29386877 |
| a staging table of post-ovipositional development for the south american collared lizard tropidurus torquatus (squamata: tropiduridae). | the mouse, chicken, african clawed frog, and zebrafish are considered ¨model organisms¨ due to their extensive embryological and genetic characterization. however, they are far from representative of known diversity, impairing phylogenetic analyses of developmental patterns. since squamates have historically received limited attention in developmental studies, we here describe the developmental sequence for tropidurus torquatus, and provide the first post-ovipositional developmental series for t ... | 2017 | 27741560 |
| molecular evolution of two distinct dmrt1 promoters for germ and somatic cells in vertebrate gonads. | the transcription factor dmrt1 has important functions in two distinct processes, somatic-cell masculinization and germ-cell development in mammals. however, it is unknown whether the functions are conserved during evolution, and what mechanism underlies its expression in the two cell lineages. our analysis of the xenopus laevis and silurana tropicalis dmrt1 genes indicated the presence of two distinct promoters: one upstream of the noncoding first exon (ncex1), and one within the first intron. ... | 2017 | 27927791 |
| amphibase: a new genomic resource for non-model amphibian species. | more than five thousand genes annotated in the recently published xenopus laevis and xenopus tropicalis genomes do not have a candidate orthologous counterpart in other vertebrate species. to determine whether these sequences represent genuine amphibian-specific genes or annotation errors, it is necessary to analyze them alongside sequences from other amphibian species. however, due to large genome sizes and an abundance of repeat sequences, there are limited numbers of gene sequences available ... | 2017 | 28095648 |
| functional characterization of an aquaporin from a microsporidium, nosema bombycis. | microsporidia are a diverse group of eukaryotic organisms, capable of causing parasitic infections in both vertebrates and invertebrates. during the germination process, there is an increase in the osmotic pressure of microsporidian spores. as part of this study, we cloned a homologous aquaporin gene in nosema bombycis, and named it nosema bombycis aquaporin (nbaqp). sequence analysis revealed that the nbaqp contains an open reading frame with a length of 750 bp and encodes a polypeptide of 249 ... | 2017 | 28749993 |
| iron is a substrate of the plasmodium falciparum chloroquine resistance transporter pfcrt in xenopus oocytes. | the chloroquine resistance transporter of the human malaria parasite plasmodium falciparum, pfcrt, is an important determinant of resistance to several quinoline and quinoline-like antimalarial drugs. pfcrt also plays an essential role in the physiology of the parasite during development inside erythrocytes. however, the function of this transporter besides its role in drug resistance is still unclear. using electrophysiological and flux experiments conducted on pfcrtexpressing xenopus laevis oo ... | 2017 | 28768767 |
| multi-omics analysis sheds light on the evolution and the intracellular lifestyle strategies of spotted fever group rickettsia spp. | arthropod-borne rickettsia species are obligate intracellular bacteria which are pathogenic for humans. within this genus, rickettsia slovaca and rickettsia conorii cause frequent and potentially severe infections, whereas rickettsia raoultii and rickettsia massiliae cause rare and milder infections. all four species belong to spotted fever group (sfg) rickettsiae. however, r. slovaca and r. raoultii cause scalp eschar and neck lymphadenopathy (senlat) and are mainly associated with dermacentor ... | 2017 | 28775717 |
| toxicity effects of functionalized quantum dots, gold and polystyrene nanoparticles on target aquatic biological models: a review. | nano-based products are widespread in several sectors, including textiles, medical-products, cosmetics, paints and plastics. nanosafety and safe-by-design are driving nanoparticle (np) production and applications through np functionalization (@nps). indeed, @nps frequently present biological effects that differ from the parent material. this paper reviews the impact of quantum dots (qds), gold nanoparticles (aunps), and polystyrene-cored nps (psnps), evidencing the role of np functionalization i ... | 2017 | 28858240 |
| first parasitological study of the african clawed frog (xenopus laevis, amphibia) in chile. | introduced species can arrive into new territories with parasites; however, these species are expected to face lower parasite richness than in their original regions. both introduced hosts and parasites can affect native fauna. since their release into the wild in chile following laboratory use, xenopus laevis daudin, 1802 has widely spread throughout central chile. the only pathogen described on the host is the fungus batrachochytrium dendrobatidis longcore, pessier, nichols, 1999; thus, this i ... | 2017 | 28746452 |
| heterologous expression of panax ginseng pgtip1 confers enhanced salt tolerance of soybean cotyledon hairy roots, composite, and whole plants. | the panax ginseng tip gene pgtip1 was previously demonstrated to have high water channel activity by its heterologous expression in xenopus laevis oocytes and in yeast; it also plays a significant role in growth of pgtip1-transgenic arabidopsis plants under favorable conditions and has enhanced tolerance toward salt and drought treatment. in this work, we first investigated the physiological effects of heterologous pgtip1 expression in soybean cotyledon hairy roots or composite plants mediated b ... | 2017 | 28769947 |
| the xenopus tadpole: an in vivo model to screen drugs favoring remyelination. | in multiple sclerosis, development of screening tools for remyelination-promoting molecules is timely. | 2017 | 28752787 |
| analysis of cell size in the gastrula of ten frog species reveals a correlation of egg with cell sizes, and a conserved pattern of small cells in the marginal zone. | we investigated the relationship between egg and cell sizes in the early gastrula of ten species of frogs with eggs of 1,100-3,500 μm diameters. we asked whether differences in cell size of the vegetal region, blastocoel roof, and marginal zone of the early gastrula were associated with egg size. alternatively, we proposed that cell size differences may associate with gastrulation characteristics. the analyzed species were as follows: xenopus laevis, engystomops randi, engystomops coloradorum, e ... | 2017 | 27381278 |
| three-dimensional reconstruction of the cranial and anterior spinal nerves in early tadpoles of xenopus laevis (pipidae, anura). | xenopus laevis is one of the most widely used model organism in neurobiology. it is therefore surprising, that no detailed and complete description of the cranial nerves exists for this species. using classical histological sectioning in combination with fluorescent whole mount antibody staining and micro-computed tomography we prepared a detailed innervation map and a freely-rotatable three-dimensional (3d) model of the cranial nerves and anterior-most spinal nerves of early x. laevis tadpoles. ... | 2017 | 29218708 |
| effects of a commonly used glyphosate-based herbicide formulation on early developmental stages of two anuran species. | environmental contamination, especially due to the increasing use of pesticides, is suggested to be one out of six main reasons for the global amphibian decline. adverse effects of glyphosate-based herbicides on amphibians have been already discussed in several studies with different conclusions, especially regarding sublethal effects at environmentally relevant concentrations. therefore, we studied the acute toxic effects (mortality, growth, and morphological changes) of the commonly used glyph ... | 2017 | 27785717 |
| comparative micrornaome analysis of the testis and ovary of the chinese giant salamander. | micrornas (mirnas) are 18-24 nucleotides non-coding rnas that regulate gene expression by post-transcriptional suppression of mrna. the chinese giant salamander (cgs, andrias davidianus), which is an endangered species, has become one of the important models of animal evolution; however, no mirna studies on this species have been conducted. in this study, two small rna libraries of cgs ovary and testis were constructed using deep sequencing technology. a bioinformatics pipeline was developed to ... | 2017 | 28630098 |
| genomic epidemiology of the emerging pathogen batrachochytrium dendrobatidis from native and invasive amphibian species in chile. | emerging fungal diseases represent a threat to food security, animal and human health worldwide. amphibian chytridiomycosis, caused by the fungus batrachochytrium dendrobatidis (bd), has been associated with catastrophic and well-documented amphibian population declines and extinctions. for the first time, bd was cultured from native and non-native wild amphibians in chile. phylogenomic analyses revealed that chilean isolates avs2, avs4 and avs7 group within the global panzootic lineage of bd (b ... | 2017 | 29205924 |
| comparative study of diclofenac-induced embryotoxicity and teratogenesis in xenopus laevis and lithobates catesbeianus, using the frog embryo teratogenesis assay: xenopus (fetax). | water is an increasingly deteriorated, limited natural resource due to population increase and industrialization. also, the widespread use of pharmaceuticals in modern society leads to their presence in domestic, hospital and industrial effluents. due to their analgesic properties, some of the most commonly used pharmaceuticals are nonsteroidal anti-inflammatory drugs (nsaids). high concentrations of one these products, diclofenac (dcf), have been detected in effluents and water bodies of differ ... | 2017 | 27644024 |
| vitamin a induced homeotic hindlimb formation on dorsal and ventral sides of regenerating tissue of amputated tails of japanese brown frog tadpoles. | when anuran tadpoles are treated with vitamin a after tail amputation, hindlimb-like structures can be generated instead of the lost tail part at the amputation site. this homeotic transformation was initially expected to be a key to understanding the body plan of vertebrates. unfortunately, homeotic limb formation has been reproduced in only some indian frog species and a european species, but not in experimental anurans such as xenopus laevis or rana catesbeiana. consequently, this fascinating ... | 2017 | 29094344 |
| transcriptomic and macroevolutionary evidence for phenotypic uncoupling between frog life history phases. | anuran amphibians undergo major morphological transitions during development, but the contribution of their markedly different life-history phases to macroevolution has rarely been analysed. here we generate testable predictions for coupling versus uncoupling of phenotypic evolution of tadpole and adult life-history phases, and for the underlying expression of genes related to morphological feature formation. we test these predictions by combining evidence from gene expression in two distantly r ... | 2017 | 28504275 |
| expression of the aquaglyceroporin hc-9 in a freeze-tolerant amphibian that accumulates glycerol seasonally. | as ambient temperatures fall in the autumn, freeze-tolerant cope's gray treefrogs, dryophytes chrysoscelis (formerly hyla chrysoscelis), accumulate glycerol as a cryoprotective agent. we hypothesized that these treefrogs express an ortholog of the mammalian aquaglyceroporin aqp9 and that aqp9 expression is upregulated in the cold to facilitate glycerol transport. we sequenced 1790 bp from cloned cdna that codes for a 315 amino acid protein, hc-9, containing the predicted six transmembrane spanni ... | 2017 | 28784850 |
| expression of cyclin d1, cyclin d2, and n-myc in embryos of the direct developing frog eleutherodactylus coqui, with a focus on limbs. | species of frogs that develop directly have removed the tadpole from their ontogeny and form adult structures precociously. to see whether cell cycle regulators could be involved in this altered embryogenesis, we examined the expression of ccnd1, ccnd2, and mycn in embryos of the direct developing frog, eleutherodactylus coqui. notable differences compared to embryos of xenopus laevis, a species with a tadpole, included prominent expression of ccnd2 in the midbrain and ccnd1 in the mandibular ne ... | 2017 | 23473789 |
| aquaglyceroporins are the entry pathway of boric acid in trypanosoma brucei. | the boron element possesses a range of different effects on living beings. it is essential to beneficial at low concentrations, but toxic at excessive concentrations. recently, some boron-based compounds have been identified as promising molecules against trypanosoma brucei, the causative agent of sleeping sickness. however, until now, the boron metabolism and its access route into the parasite remained elusive. the present study addressed the permeability of t. brucei aquaglyceroporins (tbaqps) ... | 2017 | 28087364 |
| functional characterisation and cell specificity of bvsut1, the transporter that loads sucrose into the phloem of sugar beet (beta vulgaris l.) source leaves. | sugar beet (beta vulgaris l.) is one of the most important sugar-producing plants worldwide and provides about one third of the sugar consumed by humans. here we report on molecular characterisation of the bvsut1 gene and on the functional characterisation of the encoded transporter. in contrast to the recently identified tonoplast-localised sucrose transporter bvtst2.1 from sugar beet taproots, which evolved within the monosaccharide transporter (mst) superfamily, bvsut1 represents a classical ... | 2017 | 28075052 |
| sucrose transporter localization and function in phloem unloading in developing stems. | how sucrose transporters (suts) regulate phloem unloading in monocot stems is poorly understood and particularly so for species storing high suc concentrations. to this end, sorghum bicolor suts sbsut1 and sbsut5 were characterized by determining their transport properties heterologously expressed in yeast or xenopus laevis oocytes, and their in planta cellular and subcellular localization. the plasma membrane-localized sbsut1 and sbsut5 exhibited a strong selectivity for suc and high suc affini ... | 2017 | 27986867 |
| h(+)-dependent inorganic phosphate uptake in trypanosoma brucei is influenced by myo-inositol transporter. | trypanosoma brucei is an extracellular protozoan parasite that causes human african trypanosomiasis or "sleeping sickness". during the different phases of its life cycle, t. brucei depends on exogenous inorganic phosphate (pi), but little is known about the transport of pi in this organism. in the present study, we showed that the transport of (32)pi across the plasma membrane follows michaelis-menten kinetics and is modulated by ph variation, with higher activity at acidic ph. bloodstream forms ... | 2017 | 28185085 |
| targeting functional noncoding rnas. | noncoding rnas have essential biochemical functions in different areas of cellular metabolism, including protein synthesis, rna splicing, protein secretion, and dna replication. we have successfully used morpholino antisense oligonucleotides for the functional inactivation of small noncoding rnas required for dna replication (y rnas in vertebrates and stem-bulge rnas in nematodes). here we discuss specific issues of targeting functional noncoding rnas for inactivation by morpholino antisense oli ... | 2017 | 28364241 |
| isolation and functional characterization of cslsi1, a silicon transporter gene in cucumis sativus. | cucumber (cucumis sativus) is a widely grown cucurbitaceous vegetable that exhibits a relatively high capacity for silicon (si) accumulation, but the molecular mechanism for silicon uptake remains to be clarified. here we isolated and characterized cslsi1, a gene encoding a silicon transporter in cucumber (cv. mch-4). cslsi1 shares 55.70 and 90.63% homology with the lsi1s of a monocot and dicot, rice (oryza sativa) and pumpkin (cucurbita moschata), respectively. cslsi1 was predominantly expresse ... | 2017 | 27701737 |
| cloning and expression analysis of zygote arrest 1 (zar1) in new zealand white rabbits. | zygote arrest 1 (zar1) is an oocyte-specific maternal-effect gene. previous studies indicate that zar1 plays important role in early embryo development, but little is known about its function in rabbit. the objectives of this study were to clone the new zealand white rabbit zar1 gene and to investigate its expression in various organs in groups of animals with different reproductive traits.we obtained a 709-bp zar1 cdna fragment consisting of an 8-bp exon 1, 161-bp exon 2, 75-bp exon 3, 271-bp e ... | 2017 | 28360383 |
| models of amphibian myogenesis - the case of bombina variegata. | several different models of myogenesis describing early stages of amphibian paraxial myotomal myogenesis are known. myoblasts of xenopus laevis and hymenochirus boettgeri change their position from perpendicular to parallel, in relation to axial organs, and differentiate into mononucleate myotubes. in bombina variegate the myotomal myoblasts change their shape from round to elongate and then differentiate into mononuclear, morphologically mature myotubes. in pelobates fuscus and triturus vulgari ... | 2017 | 28287243 |
| two spatially and temporally distinct ca(2+) signals convey arabidopsis thaliana responses to k(+) deficiency. | in plants, potassium (k(+) ) homeostasis is tightly regulated and established against a concentration gradient to the environment. despite the identification of ca(2+) -regulated kinases as modulators of k(+) channels, the immediate signaling and adaptation mechanisms of plants to low-k(+) conditions are only partially understood. to assess the occurrence and role of ca(2+) signals in arabidopsis thaliana roots, we employed ratiometric analyses of ca(2+) dynamics in plants expressing the ca(2+) ... | 2017 | 27579668 |
| polar localization of the nip5;1 boric acid channel is maintained by endocytosis and facilitates boron transport in arabidopsis roots. | boron uptake in arabidopsis thaliana is mediated by nodulin 26-like intrinsic protein (nip)5;1, a boric acid channel that is located preferentially on the soil side of the plasma membrane in root cells. however, the mechanism underlying this polar localization is poorly understood. here, we show that the polar localization of nip5;1 in epidermal and endodermal root cells is mediated by the phosphorylation of thr residues in the conserved tpg (thrprogly) repeat in the n-terminal region of nip5;1. ... | 2017 | 28341806 |
| 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 |
| 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 |