Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| effects of freezing and activation on membrane quality and dna damage in xenopus tropicalis and xenopus laevis spermatozoa. | there is growing concern over the effect of sperm cryopreservation on dna integrity and the subsequent development of offspring generated from this cryopreserved material. in the present study, membrane integrity and dna stability of xenopus laevis and xenopus tropicalis spermatozoa were evaluated in response to cryopreservation with or without activation, a process that happens upon exposure to water to spermatozoa of some aquatic species. a dye exclusion assay revealed that sperm plasma membra ... | 2017 | 27692061 |
| an implantable eng detector with in-system velocity selective recording (vsr) capability. | detection and classification of electroneurogram (eng) signals in the peripheral nervous system can be achieved by velocity selective recording (vsr) using multi-electrode arrays. this paper describes an implantable vsr-based eng recording system representing a significant development in the field since it is the first system of its type that can record naturally evoked eng and be interfaced wirelessly using a low data rate transcutaneous link. the system consists of two cmos asics one of which ... | 2017 | 27638107 |
| electrophysiological actions of synthetic cathinones on monoamine transporters. | products containing psychoactive synthetic cathinones, such as mephedrone and 3,4-methylenedioxypyrovalerone (mdpv) are prevalent in our society. synthetic cathinones are structurally similar to methamphetamine, and numerous synthetics have biological activity at dopamine, serotonin, and norepinephrine transporters. importantly, monoamine transporters co-transport sodium ions along with their substrate, and movement of substrates and ions through the transporter can generate measurable ionic cur ... | 2017 | 27677783 |
| the sox transcriptional factors: functions during intestinal development in vertebrates. | the intestine has long been studied as a model for adult stem cells due to the life-long self-renewal of the intestinal epithelium through the proliferation of the adult intestinal stem cells. recent evidence suggests that the formation of adult intestinal stem cells in mammals takes place during the thyroid hormone-dependent neonatal period, also known as postembryonic development, which resembles intestinal remodeling during frog metamorphosis. studies on the metamorphosis in xenopus laevis ha ... | 2017 | 27567710 |
| 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 |
| insulin-like growth factor 1 regulation of proliferation and differentiation of xenopus laevis myogenic cells in vitro. | to understand the mechanism of muscle remodeling during xenopus laevis metamorphosis, we examined the in vitro effect of insulin-like growth factor 1 (igf-1) on growth and differentiation of three different-fate myogenic cell populations: tadpole tail, tadpole dorsal, and young adult leg muscle. igf-1 promoted growth and differentiation of both tail and leg myogenic cells only under conditions where these cells could proliferate. inhibition of cell proliferation by dna synthesis inhibitor cytosi ... | 2017 | 27699652 |
| robust identification of ptbp1-dependent splicing events by a junction-centric approach in xenopus laevis. | regulation of alternative splicing is an important process for cell differentiation and development. down-regulation of ptbp1, a regulatory rna-binding protein, leads to developmental skin defects in xenopus laevis. to identify ptbp1-dependent splicing events potentially related to the phenotype, we conducted rnaseq experiments following ptbp1 depletion. we systematically compared exon-centric and junction-centric approaches to detect differential splicing events. we showed that the junction-cen ... | 2017 | 27546377 |
| translational profiling of retinal ganglion cell optic nerve regeneration in xenopus laevis. | unlike adult mammals, adult frogs regrow their optic nerve following a crush injury, making xenopus laevis a compelling model for studying the molecular mechanisms that underlie neuronal regeneration. using translational ribosome affinity purification (trap), a method to isolate ribosome-associated mrnas from a target cell population, we have generated a transcriptional profile by rna-seq for retinal ganglion cells (rgc) during the period of recovery following an optic nerve injury. based on bio ... | 2017 | 27471010 |
| 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 |
| 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 |
| 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 |
| xenmine: a genomic interaction tool for the xenopus community. | the xenopus community has embraced recent advances in sequencing technology, resulting in the accumulation of numerous rna-seq and chip-seq datasets. however, easily accessing and comparing datasets generated by multiple laboratories is challenging. thus, we have created a central space to view, search and analyze data, providing essential information on gene expression changes and regulatory elements present in the genome. xenmine (www.xenmine.org) is a user-friendly website containing publishe ... | 2017 | 27157655 |
| exploring the functions of nonclassical mhc class ib genes in xenopus laevis by the crispr/cas9 system. | a large family of highly related and clustered xenopus nonclassical mhc class ib (xnc) genes influences xenopus laevis immunity and potentially other physiological functions. using rna interference (rnai) technology, we previously demonstrated that one of xnc genes, xnc10.1, is critical for the development and function of a specialized innate t (it) cell population. however, rnai limitation such as a variable and unstable degree of gene silencing in f0 and f1 generations is hampering a thorough ... | 2017 | 27318386 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| extinction of an introduced warm-climate alien species, xenopus laevis, by extreme weather events. | invasive, non-native species represent a major threat to biodiversity worldwide. the african amphibian xenopus laevis is widely regarded as an invasive species and a threat to local faunas. populations originating at the western cape, south africa, have been introduced on four continents, mostly in areas with a similar mediterranean climate. some introduced populations are also established in cooler environments where persistence for many decades suggests a capacity for long-term adaptation. in ... | 2017 | 26430383 |
| fmrp regulates neurogenesis in vivo in xenopus laevis tadpoles. | fragile x syndrome (fxs) is the leading known monogenic form of autism and the most common form of inherited intellectual disability. fxs results from silencing the fmr1 gene during embryonic development, leading to loss of fragile x mental retardation protein (fmrp), an rna-binding protein that regulates mrna transport, stability, and translation. fxs is commonly thought of as a disease of synaptic dysfunction, however, fmrp expression is lost early in embryonic development, well before most sy ... | 2017 | 25844398 |
| methylmercury exposure during early xenopus laevis development affects cell proliferation and death but not neural progenitor specification. | methylmercury (mehg) is a widespread environmental toxin that preferentially and adversely affects developing organisms. to investigate the impact of mehg toxicity on the formation of the vertebrate nervous system at physiologically relevant concentrations, we designed a graded phenotype scale for evaluating xenopus laevis embryos exposed to mehg in solution. embryos displayed a range of abnormalities in response to mehg, particularly in brain development, which is influenced by both mehg concen ... | 2017 | 25496965 |
| 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 |
| 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 |
| effects of amphibian phylogeny, climate and human impact on the occurrence of the amphibian-killing chytrid fungus. | chytridiomycosis, due to the fungus batrachochytrium dendrobatidis (bd), has been associated with the alarming decline and extinction crisis of amphibians worldwide. because conservation programs are implemented locally, it is essential to understand how the complex interactions among host species, climate and human activities contribute to bd occurrence at regional scales. using weighted phylogenetic regressions and model selection, we investigated geographic patterns of bd occurrence along a l ... | 2017 | 28055125 |
| an inducible amphipathic helix within the intrinsically disordered c-terminus is not required for protein biosynthesis, trafficking, or garp2 interaction, but can participate in membrane curvature generation by peripherin-2/rds. | peripherin-2/rds is required for biogenesis of vertebrate photoreceptor outer segment organelles. its localization at the high curvature rim domains of outer segment disk membranes suggests that it may act to shape these structures; however, the molecular function of this protein is not yet resolved. here, we apply biochemical, biophysical, and imaging techniques, to elucidate the role(s) played by the protein's intrinsically disordered c-terminal domain, and an incipient amphipathic α-helix con ... | 2017 | 28325841 |
| immune roles of amphibian (xenopus laevis) tadpole granulocytes during frog virus 3 ranavirus infections. | infections by frog virus 3 (fv3) and other ranaviruses (rvs) are contributing to the amphibian declines, while the mechanisms controlling anuran tadpole susceptibility and adult frog resistance to rvs, including the roles of polymorphonuclear granulocytes (pmns) during anti-fv3 responses, remain largely unknown. since amphibian kidneys represent an important fv3 target, the inability of amphibian (xenopus laevis) tadpoles to mount effective kidney inflammatory responses to fv3 is thought to cont ... | 2017 | 28238879 |
| amphibian (xenopus laevis) tadpoles and adult frogs mount distinct interferon responses to the frog virus 3 ranavirus. | infections of amphibians by frog virus 3 (fv3) and other ranavirus genus members are significantly contributing to the amphibian declines, yet much remains unknown regarding amphibian antiviral immunity. notably, amphibians represent an important step in the evolution of antiviral interferon (ifn) cytokines as they are amongst the first vertebrates to possess both type i and type iii ifns. accordingly, we examined the roles of type i and iii ifns in the skin of fv3-challenged amphibian xenopus l ... | 2017 | 28081430 |
| long term effects of carbaryl exposure on antiviral immune responses in xenopus laevis. | water pollutants associated with agriculture may contribute to the increased prevalence of infectious diseases caused by ranaviruses. we have established the amphibian xenopus laevis and the ranavirus frog virus 3 (fv3) as a reliable experimental platform for evaluating the effects of common waterborne pollutants, such as the insecticide carbaryl. following 3 weeks of exposure to 10 ppb carbaryl, x. laevis tadpoles exhibited a marked increase in mortality and accelerated development. exposure at ... | 2017 | 27988452 |
| hepatitis e virus orf3 is a functional ion channel required for release of infectious particles. | hepatitis e virus (hev) is the leading cause of enterically transmitted viral hepatitis globally. of hev's three orfs, the function of orf3 has remained elusive. here, we demonstrate that via homophilic interactions orf3 forms multimeric complexes associated with intracellular endoplasmic reticulum (er)-derived membranes. hev orf3 shares several structural features with class i viroporins, and the function of hev orf3 can be maintained by replacing it with the well-characterized viroporin influe ... | 2017 | 28096411 |
| the malaria parasite's lactate transporter pffnt is the target of antiplasmodial compounds identified in whole cell phenotypic screens. | in this study the 'malaria box' chemical library comprising 400 compounds with antiplasmodial activity was screened for compounds that perturb the internal ph of the malaria parasite, plasmodium falciparum. fifteen compounds induced an acidification of the parasite cytosol. two of these did so by inhibiting the parasite's formate nitrite transporter (pffnt), which mediates the h+-coupled efflux from the parasite of lactate generated by glycolysis. both compounds were shown to inhibit lactate tra ... | 2017 | 28178359 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| quantitative comparative analysis of the nasal chemosensory organs of anurans during larval development and metamorphosis highlights the relative importance of chemosensory subsystems in the group. | the anuran peripheral olfactory system is composed of a number of subsystems, represented by distinct neuroepithelia. these include the main olfactory epithelium and vomeronasal organ (found in most tetrapods) and three specialized epithelia of anurans: the buccal-exposed olfactory epithelium of larvae, and the olfactory recess and middle chamber epithelium of postmetamorphic animals. to better characterize the developmental changes in these subsystems across the life cycle, morphometric changes ... | 2017 | 28503895 |
| differences in mobility at the range edge of an expanding invasive population of xenopus laevis in the west of france. | theoretical models predict that spatial sorting at the range edge of expanding populations should favor individuals with increased mobility relative to individuals at the center of the range. despite the fact that empirical evidence for the evolution of locomotor performance at the range edge is rare, data on cane toads support this model. however, whether this can be generalized to other species remains largely unknown. here, we provide data on locomotor stamina and limb morphology in individua ... | 2017 | 28100805 |
| spinal cord cells from pre-metamorphic stages differentiate into neurons and promote axon growth and regeneration after transplantation into the injured spinal cord of non-regenerative xenopus laevis froglets. | mammals are unable to regenerate its spinal cord after a lesion, meanwhile, anuran amphibians are capable of spinal cord regeneration only as larvae, and during metamorphosis, this capability is lost. sox2/3+ cells present in the spinal cord of regenerative larvae are required for spinal cord regeneration. here we evaluate the effect of the transplantation of spinal cord cells from regenerative larvae into the resected spinal cord of non-regenerative stages (nr-stage). donor cells were able to s ... | 2017 | 29326551 |
| competition and feeding ecology in two sympatric xenopus species (anura: pipidae). | the widespread african clawed frog (xenopus laevis) occurs in sympatry with the iucn endangered cape platanna (xenopus gilli) throughout its entire range in the south-western cape, south africa. in order to investigate aspects of the interspecific competition between populations of x. laevis and x. gilli, an assessment of their niche differentiation was conducted through a comprehensive study on food composition and trophic niche structure at two study sites: the cape of good hope (cogh) and kle ... | 2017 | 28439453 |
| limited genomic consequences of hybridization between two african clawed frogs, xenopus gilli and x. laevis (anura: pipidae). | the cape platanna, xenopus gilli, an endangered frog, hybridizes with the african clawed frog, x. laevis, in south africa. estimates of the extent of gene flow between these species range from pervasive to rare. efforts have been made in the last 30 years to minimize hybridization between these two species in the west population of x. gilli, but not the east populations. to further explore the impact of hybridization and the efforts to minimize it, we examined molecular variation in one mitochon ... | 2017 | 28439068 |
| a glyphosate micro-emulsion formulation displays teratogenicity in xenopus laevis. | glyphosate is the active ingredient in broad-spectrum herbicide formulations used in agriculture, domestic area and aquatic weed control worldwide. its market is growing steadily concurrently with the cultivation of glyphosate-tolerant transgenic crops and emergence of weeds less sensitive to glyphosate. ephemeral and lentic waters near to agricultural lands, representing favorite habitats for amphibian reproduction and early life-stage development, may thus be contaminated by glyphosate based h ... | 2017 | 29306033 |
| bioelectric regulation of innate immune system function in regenerating and intact xenopus laevis. | two key inputs that regulate regeneration are the function of the immune system, and spatial gradients of transmembrane potential (vmem). endogenous bioelectric signaling in somatic tissues during regenerative patterning is beginning to be understood, but its role in the context of immune response has never been investigated. here, we show that vmem levels modulate innate immunity activity in xenopus laevis embryos. we developed an assay in which x. laevis embryos are infected with a uropathogen ... | 2017 | 29302351 |
| chromosome divergence during evolution of the tetraploid clawed frogs, xenopus mellotropicalis and xenopus epitropicalis as revealed by zoo-fish. | whole genome duplication (wgd) generates new species and genomic redundancy. in african clawed frogs of the genus xenopus, this phenomenon has been especially important in that (i) all but one extant species are polyploid and (ii) whole genome sequences of some species provide an evidence for genomic rearrangements prior to or after wgd. within xenopus in the subgenus silurana, at least one allotetraploidization event gave rise to three extant tetraploid (2n = 4x = 40) species-xenopus mellotropi ... | 2017 | 28545147 |
| microprobe capillary electrophoresis mass spectrometry for single-cell metabolomics in live frog (xenopus laevis) embryos. | the quantification of small molecules in single cells raises new potentials for better understanding the basic processes that underlie embryonic development. to enable single-cell investigations directly in live embryos, new analytical approaches are needed, particularly those that are sensitive, selective, quantitative, robust, and scalable to different cell sizes. here, we present a protocol that enables the in situ analysis of metabolism in single cells in freely developing embryos of the sou ... | 2017 | 29286491 |
| 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 |
| rna helicase mov10 is essential for gastrulation and cns development. | mov10 is an rna helicase that modulates access of argonaute 2 to microrna recognition elements in mrnas. we examined the role of mov10 in xenopus laevis development and show a critical role for mov10 in gastrulation and in the development of the central nervous system. | 2017 | 29266590 |
| dynamic intramolecular regulation of the histone chaperone nucleoplasmin controls histone binding and release. | nucleoplasmin (npm) is a highly conserved histone chaperone responsible for the maternal storage and zygotic release of histones h2a/h2b. npm contains a pentameric n-terminal core domain and an intrinsically disordered c-terminal tail domain. though intrinsically disordered regions are common among histone chaperones, their roles in histone binding and chaperoning remain unclear. using an nmr-based approach, here we demonstrate that the xenopus laevis npm tail domain controls the binding of hist ... | 2017 | 29263320 |
| differentiation-dependent antiviral capacities of amphibian (xenopus laevis) macrophages. | infections by ranaviruses such as frog virus 3 (fv3) are significantly contributing to the worldwide amphibian population declines. notably, amphibian macrophages (mφs) are important to both the fv3 infection strategies and the immune defense against this pathogen. however, the mechanisms underlying amphibian mφ fv3 susceptibility and resistance remain unknown. mφ differentiation is mediated by signaling through the colony-stimulating factor-1 receptor (csf-1r), which is now known to be bound by ... | 2017 | 29259133 |
| tight junctions negatively regulate mechanical forces applied to adherens junctions in vertebrate epithelial tissue. | epithelia are layers of polarised cells tightly bound to each other by adhesive contacts. epithelia act as barriers between an organism and its external environment. understanding how epithelia maintain their essential integrity while remaining sufficiently plastic to allow events such as cytokinesis to take place is a key biological problem. in vertebrates, the remodelling and reinforcement of adherens junctions maintains epithelial integrity during cytokinesis. the involvement of tight junctio ... | 2017 | 29246943 |
| rnas coordinate nuclear envelope assembly and dna replication through elys recruitment to chromatin. | upon fertilisation, the sperm pronucleus acquires the competence to replicate the genome through a cascade of events that link chromatin remodelling to nuclear envelope formation. the factors involved have been partially identified and are poorly characterised. here, using xenopus laevis egg extracts we show that rnas are required for proper nuclear envelope assembly following sperm dna decondensation. although chromatin remodelling and pre-replication complex formation occur normally, rna-deple ... | 2017 | 29242643 |
| functional reintegration of sensory neurons and transitional dendritic reduction of mitral/tufted cells during injury-induced recovery of the larval xenopus olfactory circuit. | understanding the mechanisms involved in maintaining lifelong neurogenesis has a clear biological and clinical interest. in the present study, we performed olfactory nerve transection on larval xenopus to induce severe damage to the olfactory circuitry. we surveyed the timing of the degeneration, subsequent rewiring and functional regeneration of the olfactory system following injury. a range of structural labeling techniques and functional calcium imaging were performed on both tissue slices an ... | 2017 | 29234276 |
| the human dna glycosylases neil1 and neil3 excise psoralen-induced dna-dna cross-links in a four-stranded dna structure. | interstrand cross-links (icls) are highly cytotoxic dna lesions that block dna replication and transcription by preventing strand separation. previously, we demonstrated that the bacterial and human dna glycosylases nei and neil1 excise unhooked psoralen-derived icls in three-stranded dna via hydrolysis of the glycosidic bond between the crosslinked base and deoxyribose sugar. furthermore, neil3 from xenopus laevis has been shown to cleave psoralen- and abasic site-induced icls in xenopus egg ex ... | 2017 | 29234069 |
| antagonistic effect of dopamine structural analogues on human gabaρ1 receptor. | gabaergic and dopaminergic pathways are co-localized in several areas of the central nervous system and recently several reports have shown co-release of both neurotransmitters. the gaba-a receptor (β and ρ1 subunits) is modulated by dopamine (da) and, interestingly, gabaρ1 can be modulated by several biogenic amines. here we explored the effects of the metabolites of the dopaminergic pathway and other structural analogues of da on gabaρ1 and the da gated ion channel (lgc-53) from caenorhabditis ... | 2017 | 29234054 |
| increasing the length and hydrophobicity of the c-terminal sequence of transthyretin strengthens its binding affinity to retinol binding protein. | transthyretin (ttr) is a transporter for thyroid hormone (th) and retinol, the latter via binding with retinol binding protein (rbp). both the n-terminal and c-terminal regions of the ttr subunit are located in close proximity to the central binding channel for ligands. during the evolution of vertebrates, these regions changed in length and hydropathy. the changes in the n-terminal sequence were demonstrated to affect the binding affinities for ths and rbp. here, the effects of changes in the c ... | 2017 | 29226076 |
| species specific rna a-to-i editing of mosquito rdl modulates gaba potency and influences agonistic, potentiating and antagonistic actions of ivermectin. | the insect gaba receptor, rdl, is the target of several classes of pesticides. the peptide sequences of rdl are generally highly conserved between diverse insects. however, rna a-to-i editing can effectively alter amino acid residues of rdl in a species specific manner, which can affect the potency of gaba and possibly insecticides. we report here that rna a-to-i editing alters the gene products of rdl in three mosquito disease vectors, recoding five amino acid residues in rdl of aedes aegypti a ... | 2017 | 29223796 |
| xenopus laevis as a model organism for the study of spinal cord formation, development, function and regeneration. | the spinal cord is the first central nervous system structure to develop during vertebrate embryogenesis, underscoring its importance to the organism. because of its early formation, accessibility to the developing spinal cord in amniotes is challenging, often invasive and the experimental approaches amenable to model systems like mammals are limited. in contrast, amphibians, in general and the african-clawed frog xenopus laevis, in particular, offer model systems in which the formation of the s ... | 2017 | 29218002 |
| interaction of purinergic p2x4 and p2x7 receptor subunits. | p2x4 and p2x7 are members of the p2x receptor family, comprising seven isoforms (p2x1-p2x7) that form homo- and heterotrimeric non-specific cation channels gated by extracellular atp. p2x4 and p2x7 are widely coexpressed, particularly in secretory epithelial cells and immune and inflammatory cells, and regulate inflammation and nociception. although functional heteromerization has been established for p2x2 and p2x3 subunits expressed in sensory neurons, there are contradictory reports regarding ... | 2017 | 29213241 |
| spindle-to-cortex communication in cleaving frog eggs. | during cytokinesis, the mitotic spindle communicates with the cell cortex to position a cleavage furrow that will cut through the cell in the plane defined by the metaphase plate. we investigated the molecular basis of this communication in xenopus laevis eggs, where the signal has to travel ∼400 µm in ∼30 min to reach the cortex from the first anaphase spindle. at anaphase onset, huge microtubule asters grow out from the poles of the spindle and meet at the plane previously defined by the metap ... | 2017 | 29196560 |
| the ectodomain of cadherin-11 binds to erbb2 and stimulates akt phosphorylation to promote cranial neural crest cell migration. | during development, a multi-potent group of cells known as the cranial neural crest (cnc) migrate to form craniofacial structures. proper migration of these cells requires proteolysis of cell adhesion molecules, such as cadherins. in xenopus laevis, preventing extracellular cleavage of cadherin-11 impairs cnc migration. however, overexpression of the soluble cleavage product (ec1-3) is capable of rescuing this phenotype. the mechanism by which ec1-3 promotes cnc migration has not been investigat ... | 2017 | 29190819 |
| tissue-specific gene inactivation in xenopus laevis: knockout of lhx1 in the kidney with crispr/cas9. | studying genes involved in organogenesis is often difficult because many of these genes are also essential for early development. the allotetraploid frog, xenopus laevis, is commonly used to study developmental processes, but because of the presence of two homeologs for many genes, it has been difficult to use as a genetic model. few studies have successfully used crispr in amphibians, and currently there is no tissue-targeted knockout strategy described in xenopus the goal of this study is to d ... | 2017 | 29187504 |
| evaluating the longevity of surgically extracted xenopus laevis oocytes for the study of nematode ligand-gated ion channels. | xenopus laevis oocytes have been extensively used as a heterologous expression system for the study of ion channels. while used successfully worldwide as tool for expressing and characterizing ion channels from a wide range of species, the limited longevity of oocytes once removed from the animal can pose significant challenges. in this study, we evaluate a simple and useful method that extends the longevity of xenopus oocytes after removal from the animal and quantitatively assessed the reliabi ... | 2017 | 29185074 |
| quantification of size effect on protein rotational mobility in cells by 19f nmr spectroscopy. | protein diffusion in living cells might differ significantly from that measured in vitro. little is known about the effect of globular protein size on rotational diffusion in cells because each protein has distinct surface properties, which result in different interactions with cellular components. to overcome this problem, the b1 domain of protein g (gb1) and several concatemers of the protein were labeled with 5-fluorotryptophan and studied by 19f nmr in escherichia coli cells, xenopus laevis ... | 2017 | 29184995 |
| the r81t mutation in the nicotinic acetylcholine receptor of aphis gossypii is associated with neonicotinoid insecticide resistance with differential effects for cyano- and nitro-substituted neonicotinoids. | the cotton aphid, aphis gossypii glover, is one of the most agriculturally important insect pests. neonicotinoid insecticides and sulfoxaflor have generally shown excellent control of a. gossypii, but these aphids have recently developed resistance against neonicotinoid insecticides. we previously characterized a field-collected a. gossypii kushima clone that showed higher resistance to nitro-substituted neonicotinoids, such as imidacloprid, than to cyano-substituted neonicotinoids, such as acet ... | 2017 | 29183611 |
| targeted base editing via rna-guided cytidine deaminases in xenopus laevis embryos. | genome editing using programmable nucleases such as crispr/cas9 or cpf1 has emerged as powerful tools for gene knock-out or knock-in in various organisms. while most genetic diseases are caused by point mutations, these genome-editing approaches are inefficient in inducing single-nucleotide substitutions. recently, cas9-linked cytidine deaminases, named base editors (bes), have been shown to convert cytidine to uridine efficiently, leading to targeted single-base pair substitutions in human cell ... | 2017 | 29179261 |
| a nonredundant role for the trpm6 channel in neural tube closure. | in humans, germline mutations in trpm6 cause autosomal dominant hypomagnesemia with secondary hypocalcemia disorder. loss of trpm6 in mice also perturbs cellular magnesium homeostasis but additionally results in early embryonic lethality and neural tube closure defects. to define the mechanisms by which trpm6 influences neural tube closure, we functionally characterized the role of trpm6 during early embryogenesis in xenopus laevis. the expression of xenopus trpm6 (xtrpm6) is elevated at the ons ... | 2017 | 29142255 |
| developmental changes in spinal neuronal properties, motor network configuration and neuromodulation at free-swimming stages of xenopus frog tadpoles. | we describe a novel preparation of the isolated brainstem and spinal cord from pro-metamorphic tadpole stages of the south african clawed frog (xenopus laevis) that permits whole cell patch-clamp recordings from neurons in the ventral spinal cord. previous research on earlier stages of the same species has provided one of the most detailed understandings of the design and operation of a cpg circuit. here we have addressed how development sculpts complexity from this more basic circuit. the prepa ... | 2017 | 29142093 |
| it's not all black and white: visual scene parameters influence optokinetic reflex performance in xenopus laevis tadpoles. | the maintenance of visual acuity during active and passive body motion is ensured by gaze-stabilizing reflexes that aim at minimizing retinal image slip. for the optokinetic reflex (okr), large-field visual motion of the surround forms the essential stimulus that activates eye movements. properties of the moving visual world influence cognitive motion perception and the estimation of visual image velocity. therefore, the performance of brainstem-mediated visuo-motor behaviors might also depend o ... | 2017 | 29141881 |
| overland movement in african clawed frogs (xenopus laevis): empirical dispersal data from within their native range. | dispersal forms are an important component of the ecology of many animals, and reach particular importance for predicting ranges of invasive species. african clawed frogs (xenopus laevis) move overland between water bodies, but all empirical studies are from invasive populations with none from their native southern africa. here we report on incidents of overland movement found through a capture-recapture study carried out over a three year period in overstrand, south africa. the maximum distance ... | 2017 | 29134157 |
| specific inhibition of gpcr-independent g protein signaling by a rationally engineered protein. | activation of heterotrimeric g proteins by cytoplasmic nonreceptor proteins is an alternative to the classical mechanism via g protein-coupled receptors (gpcrs). a subset of nonreceptor g protein activators is characterized by a conserved sequence named the gα-binding and activating (gba) motif, which confers guanine nucleotide exchange factor (gef) activity in vitro and promotes g protein-dependent signaling in cells. gba proteins have important roles in physiology and disease but remain greatl ... | 2017 | 29133411 |
| towards functional selectivity for α6β3γ2 gabaa receptors: a series of novel pyrazoloquinolinones. | the gabaa receptors are ligand-gated ion channels, which play an important role in neurotransmission. their variety of binding sites serves as an appealing target for many clinically relevant drugs. here, we explored the functional selectivity of modulatory effects at specific extracellular α+/β- interfaces, using a systematically varied series of pyrazoloquinolinones. | 2017 | 29127702 |