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effects of dietary exposure of polycyclic musk hhcb on the metamorphosis of xenopus laevis.the compound 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[γ]-2-benzopyrane (hhcb; galaxolide, chemical abstracts service number 1222-05-5) is a synthetic musk used extensively as a fragrance in many consumer products and classified as an emerging pollutant. the ecotoxicological information available for hhcb addresses exposure via water, but this compound is frequently adsorbed into particulate matter. the goal of the present study was to assess the effects of dietary exposure to seve ...201626472276
catalytic activity of human carbonic anhydrase isoform ix is displayed both extra- and intracellularly.most carbonic anhydrases catalyse the reversible conversion of carbon dioxide to protons and bicarbonate, either as soluble cytosolic enzymes, in or at intracellular organelles, or at the extracellular face of the cell membrane as membrane-anchored proteins. carbonic anhydrase isoform ix (ca ix), a membrane-bound enzyme with catalytic activity at the extracellular membrane surface, has come to prominence in recent years because of its association with hypoxic tissue, particularly tumours, often ...201626470855
bumetanide derivatives aqb007 and aqb011 selectively block the aquaporin-1 ion channel conductance and slow cancer cell migration.aquaporins (aqps) in the major intrinsic family of proteins mediate fluxes of water and other small solutes across cell membranes. aqp1 is a water channel, and under permissive conditions, a nonselective cation channel gated by cgmp. in addition to mediating fluid transport, aqp1 expression facilitates rapid cell migration in cell types including colon cancers and glioblastoma. work here defines new pharmacological derivatives of bumetanide that selectively inhibit the ion channel, but not the w ...201626467039
phosphorylation of rs1 (rsc1a1) steers inhibition of different exocytotic pathways for glucose transporter sglt1 and nucleoside transporter cnt1, and an rs1-derived peptide inhibits glucose absorption.cellular uptake adapts rapidly to physiologic demands by changing transporter abundance in the plasma membrane. the human gene rsc1a1 codes for a 67-kda protein named rs1 that has been shown to induce downregulation of the sodium-d-glucose cotransporter 1 (sglt1) and of the concentrative nucleoside transporter 1 (cnt1) in the plasma membrane by blocking exocytosis at the golgi. injecting rs1 fragments into xenopus laevis oocytes expressing sglt1 or cnt1 and measuring the expressed uptake of α-me ...201626464324
a curcumin analog, go-y078, effectively inhibits angiogenesis through actin disorganization.the inhibition of angiogenesis is a theoretically ideal chemotherapy for cancer, but there remains room for improvement. most inhibitors of angiogenesis approved to date target vascular endothelial growth factors (vegfs); however, vegfs are only one of the many classes of participant in tumor angiogenesis. because tumor angiogenesis is orchestrated by many components, including growth factors, signal transducers, and effectors, its regulation exhibits redundancy. curcumin can associate with many ...201626459768
quantitative analysis of filament branch orientation in listeria actin comet tails.several bacterial and viral pathogens hijack the host actin cytoskeleton machinery to facilitate spread and infection. in particular, listeria uses arp2/3-mediated actin filament nucleation at the bacterial surface to generate a branched network that will help propel the bacteria. however, the mechanism of force generation remains elusive due to the lack of high-resolution three-dimensional structural data on the spatial organization of the actin mother and daughter (i.e., branch) filaments with ...201626497103
in vitro model systems to investigate bile salt export pump (bsep) activity and drug interactions: a review.the bile salt export pump protein (bsep), expressed on the canalicular membranes of hepatocytes, is primarily responsible for the biliary excretion of bile salts. the inhibition of bsep transport activity can lead to an increase in intracellular bile salt levels and liver injury. this review discusses the various in vitro assays currently available for assessing the effect of drugs or other chemical entities to modulate bsep transport activity. bsep transporter assays use one of the following pl ...201626683212
waterborne exposure to triadimefon causes thyroid endocrine disruption and developmental delay in xenopus laevis tadpoles.triadimefon (tdf) is a triazole-derivative fungicide that is detectable in the environment and target agricultural products, prompting concern over its risk to wildlife and human health. in our study, nieuwkoop & faber stage 51 xenopus laevis tadpoles were exposed to different nominal concentrations tdf (0, 0.112, and 1.12mg/l) for 21 days while the tadpoles were undergoing pre-morphological development. developmental condition, bioaccumulation and thyroid hormone levels, and mrna expression of ...201627289584
gene expression profiles in testis of developing male xenopus laevis damaged by chronic exposure of atrazine.as a widely used herbicide, atrazine (az) has been extensively studied for its adverse effects on the reproductive system, especially feminization in male animals. however, the relationship of gene expression changes and associated toxicological endpoints remains unclear. in this study, developing xenopus laevis tadpoles were exposed to concentration of az at 0.1, 1, 10 or 100 μg/l continuously. compared with froglets in the control group, there were no significant differences in body length, bo ...201627288644
electrophysiological characterization of a large set of novel variants in the scn5a-gene: identification of novel lqts3 and brs mutations.scn5a encodes for the α-subunit of the cardiac voltage-gated sodium channel nav1.5. gain-of-function mutations in scn5a are related to congenital long qt syndrome (lqts3) characterized by delayed cardiac repolarization, leading to a prolonged qt interval in the ecg. loss-of-function mutations in scn5a are related to brugada syndrome (brs), characterized by an st-segment elevation in the right precordial leads (v1-v3). the aim of this study was the characterization of a large set of novel scn5a v ...201627287068
recording temperature-induced neuronal activity through monitoring calcium changes in the olfactory bulb of xenopus laevis.the olfactory system, specialized in the detection, integration and processing of chemical molecules is likely the most thoroughly studied sensory system. however, there is piling evidence that olfaction is not solely limited to chemical sensitivity, but also includes temperature sensitivity. premetamorphic xenopus laevis are translucent animals, with protruding nasal cavities deprived of the cribriform plate separating the nose and the olfactory bulb. these characteristics make them well suited ...201627286501
heteromeric channels with different phenotypes are generated when coexpressing two p2x2 receptor isoforms.to investigate if channels with different stoichiometry are formed from p2x2 receptor isoforms during their heterologous co-expression. the two-electrode voltage-clamp technique was used to measured atp induced currents in xenopus laevis oocytes. we used a mutant (p2x2-2bm) because its atp sensitivity is lower than p2x2-2b receptors, which highlights the differences with its splice variant p2x2-1a.currents through homomeric channels had significantly different hill coefficients. p2xr are trimeri ...201627282483
the synthetic gestagen levonorgestrel directly affects gene expression in thyroid and pituitary glands of xenopus laevis tadpoles.the synthetic gestagen levonorgestrel (lng) was previously shown to perturb thyroid hormone-dependent metamorphosis in xenopus laevis. however, so far the mechanisms underlying the anti-metamorphic effects of lng remained unknown. therefore, a series of in vivo and ex vivo experiments was performed to identify potential target sites of lng action along the pituitary-thyroid axis of x. laevis tadpoles. prometamorphic tadpoles were treated in vivo with lng (0.01-10nm) for 72h and brain-pituitary a ...201627262936
rna extraction from xenopus auditory and vestibular organs for molecular cloning and expression profiling with rna-seq and microarrays.the amphibian xenopus offers a unique model system for uncovering the genetic basis of auditory and vestibular function in an organism that is well-suited for experimental manipulation during animal development. however, many procedures for analyzing gene expression in the peripheral auditory and vestibular systems mandate the ability to isolate intact rna from inner ear tissue. methods presented here facilitate preparation of high-quality inner ear rna from larval and post-metamorphic xenopus s ...201627259922
a tunable silk hydrogel device for studying limb regeneration in adult xenopus laevis.in certain amphibian models limb regeneration can be promoted or inhibited by the local wound bed environment. this research introduces a device that can be utilized as an experimental tool to characterize the conditions that promotes limb regeneration in the adult frog (xenopus laevis) model. in particular, this device was designed to manipulate the local wound environment via a hydrogel insert. initial characterization of the hydrogel insert revealed that this interaction had a significant inf ...201627257960
regulation of human kv1.4 channel activity by the antidepressant metergoline.metergoline is an ergot-derived psychoactive drug that is a ligand for various serotonin and dopamine receptors. little is known about the effect of metergoline on different types of receptors and ion channels. potassium channels are the most diverse group of ion channels. kv1.4, a shaker family k channel alpha subunit, is one of a family of voltage gated k channels that mediates transient and rapid inactivating a-type currents and n-type inactivation. we demonstrated previously that metergoline ...201627251511
impacts of climate change on the global invasion potential of the african clawed frog xenopus laevis.by altering or eliminating delicate ecological relationships, non-indigenous species are considered a major threat to biodiversity, as well as a driver of environmental change. global climate change affects ecosystems and ecological communities, leading to changes in the phenology, geographic ranges, or population abundance of several species. thus, predicting the impacts of global climate change on the current and future distribution of invasive species is an important subject in macroecologica ...201627248830
development of the larval amphibian growth and development assay: effects of benzophenone-2 exposure in xenopus laevis from embryo to juvenile.the larval amphibian growth and development assay (lagda) is a globally harmonized chemical testing guideline developed by the u.s. environmental protection agency in collaboration with japan's ministry of environment to support risk assessment. the assay is employed as a higher tiered approach to evaluate effects of chronic chemical exposure throughout multiple life stages in a model amphibian species, xenopus laevis. to evaluate the utility of the initial lagda design, the assay was performed ...201627241388
sexually dimorphic expression of dmrt1 and γh2ax in germ stem cells during gonadal development in xenopus laevis.in many animals, primordial germ cells (pgcs) migrate into developing gonads. there, they proliferate and differentiate into female and male germ stem cells (gscs), oogonia and spermatogonia, respectively. few studies have focused on the molecular mechanisms underlying the development of gsc sex determination. here, we investigated the expression of the transcription factor dmrt1 and a phosphorylated form of the histone variant h2ax (γh2ax) during gonadal development in xenopus laevis. during ea ...201627239441
the unique myelopoiesis strategy of the amphibian xenopus laevis.myeloid progenitors reside within specific hematopoietic organs and commit to progenitor lineages bearing megakaryocyte/erythrocyte (mep) or granulocyte/macrophage potentials (gmp) within these sites. unlike other vertebrates, the amphibian xenopus laevis committed macrophage precursors are absent from the hematopoietic subcapsular liver and instead reside within their bone marrow. presently, we demonstrate that while these frogs' liver-derived cells are unresponsive to recombinant forms of prin ...201627234705
luminal ca(2+) dynamics during ip3r mediated signals.the role of cytosolic ca(2+) on the kinetics of inositol 1,4,5-triphosphate receptors (ip3rs) and on the dynamics of ip3r-mediated ca(2+) signals has been studied at large both experimentally and by modeling. the role of luminal ca(2+) has not been investigated with that much detail although it has been found that it is relevant for signal termination in the case of ca(2+) release through ryanodine receptors. in this work we present the results of observing the dynamics of luminal and cytosolic ...201627232767
membrane dynamics during cellular wound repair.cells rapidly reseal after damage, but how they do so is unknown. it has been hypothesized that resealing occurs due to formation of a patch derived from rapid fusion of intracellular compartments at the wound site. however, patching has never been directly visualized. here we study membrane dynamics in wounded xenopus laevis oocytes at high spatiotemporal resolution. consistent with the patch hypothesis, we find that damage triggers rampant fusion of intracellular compartments, generating a bar ...201627226483
the role of micrornas in animal cell reprogramming.our concept of cell reprogramming and cell plasticity has evolved since john gurdon transferred the nucleus of a completely differentiated cell into an enucleated xenopus laevis egg, thereby generating embryos that developed into tadpoles. more recently, induced expression of transcription factors, oct4, sox2, klf4, and c-myc has evidenced the plasticity of the genome to change the expression program and cell phenotype by driving differentiated cells to the pluripotent state. beyond these milest ...201627224014
cadmium but not lead exposure affects xenopus laevis fertilization and embryo cleavage.among the toxicological and ecotoxicological studies, few have investigated the effects on germ cells, gametes or embryos, while an impact at these stages will result in serious damage at a population level. thus, it appeared essential to characterize consequences of environmental contaminant exposures at these stages. therefore, we proposed to assess the effects of exposure to cadmium and lead ions, alone or in a binary mixture, on early stages of xenopus laevis life cycle. fertilization and ce ...201627218424
the cardiac-restricted protein adp-ribosylhydrolase-like 1 is essential for heart chamber outgrowth and acts on muscle actin filament assembly.adprhl1, a member of the adp-ribosylhydrolase protein family, is expressed exclusively in the developing heart of all vertebrates. in the amphibian xenopus laevis, distribution of its mrna is biased towards actively growing chamber myocardium. morpholino oligonucleotide-mediated knockdown of all adprhl1 variants inhibits striated myofibril assembly and prevents outgrowth of the ventricle. the resulting ventricles retain normal electrical conduction and express markers of chamber muscle different ...201627217161
novel positive allosteric modulators of gabaa receptors with anesthetic activity.gabaa receptors are the main inhibitory neurotransmitter receptors in the brain and are targets for numerous clinically important drugs such as benzodiazepines, anxiolytics and anesthetics. we previously identified novel ligands of the classical benzodiazepine binding pocket in α1β2γ2 gabaa receptors using an experiment-guided virtual screening (egvs) method. this screen also identified novel ligands for intramembrane low affinity diazepam site(s). in the current study we have further characteri ...201627198062
identification and characterization of mitotic spindle-localized transcripts.rnas associate with the mitotic spindle in a variety of organisms, where they can spatially regulate protein production, ensure their proper segregation during cell division, or perform translation-independent roles in spindle formation. the identification of spindle-associated rnas is an important first step in understanding the biological consequences of this phenomenon. in this chapter, we describe a method to use xenopus laevis egg extracts to assemble and isolate mitotic spindles and to ide ...201627193857
assays to study mitotic centrosome and spindle pole assembly and regulation.faithful chromosome segregation during cell division requires proper bipolar spindle assembly and critically depends on spindle pole integrity. in most animal cells, spindle poles form as the result of the concerted action of various factors operating in two independent pathways of microtubule assembly mediated by chromatin/rangtp and by centrosomes. mutation or deregulation of a number of spindle pole-organizing proteins has been linked to human diseases, including cancer and microcephaly. our ...201627193852
encapsulation of xenopus egg and embryo extract spindle assembly reactions in synthetic cell-like compartments with tunable size.methods are described for preparing xenopus laevis egg and embryo cytoplasm and encapsulating extract spindle assembly reactions in cell-like compartments to investigate the effects of cell size on intracellular assembly. cytoplasm prepared from the eggs or embryos of individual frogs is screened for the ability to form interphase nuclei and metaphase spindles, and subsequently packaged, along with dna, into droplets of varying size using microfluidics. the dimensions of these cell-like droplets ...201627193845
visualizing and analyzing branching microtubule nucleation using meiotic xenopus egg extracts and tirf microscopy.mitotic and meiotic spindles consist primarily of microtubules, which originate from centrosomes and within the vicinity of chromatin. indirect evidence suggested that microtubules also originate throughout the spindle, but the high microtubule density within the spindle precludes the direct observation of this phenomenon. by using meiotic xenopus laevis egg extract and employing total internal reflection (tirf) microscopy, microtubule nucleation from preexisting microtubules could be demonstrat ...201627193844
mechanical roles of apical constriction, cell elongation, and cell migration during neural tube formation in xenopus.neural tube closure is an important and necessary process during the development of the central nervous system. the formation of the neural tube structure from a flat sheet of neural epithelium requires several cell morphogenetic events and tissue dynamics to account for the mechanics of tissue deformation. cell elongation changes cuboidal cells into columnar cells, and apical constriction then causes them to adopt apically narrow, wedge-like shapes. in addition, the neural plate in xenopus is s ...201627193152
from meiosis to mitosis - the sperm centrosome defines the kinetics of spindle assembly after fertilization in xenopus.bipolar spindle assembly in the vertebrate oocyte relies on a self-organization chromosome-dependent pathway. upon fertilization, the male gamete provides a centrosome, and the first and subsequent embryonic divisions occur in the presence of duplicated centrosomes that act as dominant microtubule organizing centres (mtocs). the transition from meiosis to embryonic mitosis involves a necessary adaptation to integrate the dominant chromosome-dependent pathway with the centrosomes to form the bipo ...201627179073
lateral line scene analysis in the purely aquatic frog xenopus laevis daudin (pipidae).the ability to locate and discriminate water surface waves that impinge simultaneously from multiple directions was studied in the clawed frog, xenopus laevis. monofrequency waves of 5-30 hz were presented from point sources at a distance of 10 cm from the frog, unless stated otherwise, and the animal's response turn towards the wave origin examined. two-choice conditioning with two simultaneous frontal waves at a 90-degree inter-wave angle revealed discrimination thresholds lower than 1 hz for ...201627172931
with no lysine l-wnk1 isoforms are negative regulators of the k+-cl- cotransporters.the k(+)-cl(-) cotransporters (kcc1-kcc4) encompass a branch of the slc12 family of electroneutral cation-coupled chloride cotransporters that translocate ions out of the cell to regulate various factors, including cell volume and intracellular chloride concentration, among others. l-wnk1 is an ubiquitously expressed kinase that is activated in response to osmotic stress and intracellular chloride depletion, and it is implicated in two distinct hereditary syndromes: the renal disease pseudohypoa ...201627170636
neural activity-dependent regulation of radial glial filopodial motility is mediated by glial cgmp-dependent protein kinase 1 and contributes to synapse maturation in the developing visual system.radial glia in the developing optic tectum extend highly dynamic filopodial protrusions within the tectal neuropil, the motility of which has previously been shown to be sensitive to neural activity and nitric oxide (no) release. using in vivo two-photon microscopy, we performed time-lapse imaging of radial glial cells and measured filopodial motility in the intact albino xenopus laevis tadpole. application of mk801 to block neuronal nmda receptor (nmdar) currents confirmed a significant reducti ...201627170125
technique to target microinjection to the developing xenopus kidney.the embryonic kidney of xenopus laevis (frog), the pronephros, consists of a single nephron, and can be used as a model for kidney disease. xenopus embryos are large, develop externally, and can be easily manipulated by microinjection or surgical procedures. in addition, fate maps have been established for early xenopus embryos. targeted microinjection into the individual blastomere that will eventually give rise to an organ or tissue of interest can be used to selectively overexpress or knock d ...201627168375
trialkyltin rexinoid-x receptor agonists selectively potentiate thyroid hormone induced programs of xenopus laevis metamorphosis.the trialkyltins tributyltin (tbt) and triphenyltin (tpt) can function as rexinoid-x receptor (rxr) agonists. we recently showed that rxr agonists can alter thyroid hormone (th) signaling in a mammalian pituitary th-responsive reporter cell line, gh3.tre-luc. the prevalence of tbt and tpt in the environment prompted us to test whether they could also affect th signaling. both trialkyltins induced the integrated luciferase reporter alone and potentiated th activation at low doses. trimethyltin, w ...201627167774
assessing primary neurogenesis in xenopus embryos using immunostaining.primary neurogenesis is a dynamic and complex process during embryonic development that sets up the initial layout of the central nervous system. during this process, a portion of neural stem cells undergo differentiation and give rise to the first populations of differentiated primary neurons within the nascent central nervous system. several vertebrate model organisms have been used to explore the mechanisms of neural cell fate specification, patterning, and differentiation. among these is the ...201627166855
deep-brain photoreception links luminance detection to motor output in xenopus frog tadpoles.nonvisual photoreceptors are widely distributed in the retina and brain, but their roles in animal behavior remain poorly understood. here we document a previously unidentified form of deep-brain photoreception in xenopus laevis frog tadpoles. the isolated nervous system retains sensitivity to light even when devoid of input from classical eye and pineal photoreceptors. these preparations produce regular bouts of rhythmic swimming activity in ambient light but fall silent in the dark. this sensi ...201627166423
delineating the grin1 phenotypic spectrum: a distinct genetic nmda receptor encephalopathy.to determine the phenotypic spectrum caused by mutations in grin1 encoding the nmda receptor subunit glun1 and to investigate their underlying functional pathophysiology.201627164704
novel exon 1 protein-coding regions n-terminally extend human kcne3 and kcne4.the 5 human (h)kcne β subunits each regulate various cation channels and are linked to inherited cardiac arrhythmias. reported here are previously undiscovered protein-coding regions in exon 1 of hkcne3 and hkcne4 that extend their encoded extracellular domains by 44 and 51 residues, which yields full-length proteins of 147 and 221 residues, respectively. full-length hkcne3 and hkcne4 transcript and protein are expressed in multiple human tissues; for hkcne4, only the longer protein isoform is d ...201627162025
up-regulation of the large-conductance ca2+-activated k+ channel by glycogen synthase kinase gsk3β.the pleotropic functions of the large conductance ca2+-activated k+ channels (maxi k+ channel or bk channels) include regulation of neuronal excitation and cell volume. kinases participating in those functions include the glycogen synthase kinase gsk3 ß which is under negative control of protein kinase b (pkb/akt). gsk3ß is inhibited by the antidepressant lithium. the present study thus explored whether gsk3ß modifies the activity of bk channels.201627537208
small gtpases rab8a and rab11a are dispensable for rhodopsin transport in mouse photoreceptors.rab11a and rab8a are ubiquitous small gtpases shown as required for rhodopsin transport in xenopus laevis and zebrafish photoreceptors by dominant negative (dn) disruption of function. here, we generated retina-specific rab11a (retrab11a) and rab8a (retrab8a) single and double knockout mice to explore the consequences in mouse photoreceptors. rhodopsin and other outer segment (os) membrane proteins targeted correctly to os and electroretinogram (erg) responses in all three mutant mouse lines wer ...201627529348
phenotypic spectrum of gabra1: from generalized epilepsies to severe epileptic encephalopathies.to delineate phenotypic heterogeneity, we describe the clinical features of a cohort of patients with gabra1 gene mutations.201627521439
involvement of protein acyltransferase zdhhc3 in maintaining oocyte meiotic arrest in xenopus laevis.fully grown oocytes of most vertebrates are arrested at prophase i of meiosis (g2 arrest). upon exposure to steroid hormones, oocytes resume meiotic process, also called g2/m transition. the g protein-signaling pathway has been shown to play essential roles in the meiotic arrest at g2 phase. previously, we showed that long chain fatty acyl-coenzyme a synthetase acsl1b was required for maintaining the meiotic arrest in xenopus acsl1b presumably synthesizes palmitoyl-coenzyme a that can be utilize ...201627512151
fragile x mental retardation protein knockdown in the developing xenopus tadpole optic tectum results in enhanced feedforward inhibition and behavioral deficits.fragile x syndrome is the leading monogenetic cause of autism and most common form of intellectual disability. previous studies have implicated changes in dendritic spine architecture as the primary result of loss of fragile x mental retardation protein (fmrp), but recent work has shown that neural proliferation is decreased and cell death is increased with either loss of fmrp or overexpression of fmrp. the purpose of this study was to investigate the effects of loss of fmrp on behavior and cell ...201627503008
ginsenoside rg3, a gating modifier of eag family k+ channels.ginsenoside 20(s)-rg3 (rg3) is a steroid glycoside that induces human ether-à-go-go-related gene type 1 (herg1, kv11.1) channels to activate at more negative potentials and to deactivate more slowly than normal. however, it is unknown whether this action is unique to herg1 channels. here we compare and contrast the mechanisms of actions of rg3 on herg1 with three other members of the ether-à-go-go (eag) k(+) channel gene family, including eag1 (kv10.1), erg3 (kv11.3), and elk1 (kv12.1). all four ...201627502018
functional joint regeneration is achieved using reintegration mechanism in xenopus laevis.a functional joint requires integration of multiple tissues: the apposing skeletal elements should form an interlocking structure, and muscles should insert into skeletal tissues via tendons across the joint. whereas newts can regenerate functional joints after amputation, xenopus laevis regenerates a cartilaginous rod without joints, a "spike." previously we reported that the reintegration mechanism between the remaining and regenerated tissues has a significant effect on regenerating joint mor ...201627499877
the sequential activation of the mitotic microtubule assembly pathways favors bipolar spindle formation.centrosome maturation is the process by which the duplicated centrosomes recruit pericentriolar components and increase their microtubule nucleation activity before mitosis. the role of this process in cells entering mitosis has been mostly related to the separation of the duplicated centrosomes and thereby to the assembly of a bipolar spindle. however, spindles can form without centrosomes. in fact, all cells, whether they have centrosomes or not, rely on chromatin-driven microtubule assembly t ...201627489339
nodal signalling in xenopus: the role of xnr5 in left/right asymmetry and heart development.nodal class tgf-β signalling molecules play essential roles in establishing the vertebrate body plan. in all vertebrates, nodal family members have specific waves of expression required for tissue specification and axis formation. in xenopus laevis, six nodal genes are expressed before gastrulation, raising the question of whether they have specific roles or act redundantly with each other. here, we examine the role of xnr5. we find it acts at the late blastula stage as a mesoderm inducer and re ...201627488374
purification of human and mammalian membrane proteins expressed in xenopus laevis frog oocytes for structural studies.this protocol describes the isolation of recombinant human and mammalian membrane proteins expressed in xenopus laevis frog oocytes for structural studies. the cdna-derived crna of the desired genes is injected into several hundreds of oocytes, which are incubated for several days to allow protein expression. recombinant proteins are then purified via affinity chromatography. the novelty of this method comes from the design of a plasmid that produces multi-tagged proteins and, most importantly, ...201627485339
continued studies on the effects of simazine on the liver histological structure and metamorphosis in the developing xenopus laevis.this study continued our previous work (sai et al. in bull environ contam toxicol 95:157-163, 2015a) by analysing the effects of simazine on the liver histological structure and metamorphosis in the developing xenopus laevis. tadpoles (nieuwkoop-faber stage 46) were exposed to simazine at 0.1, 1.2, 11.0 and 100.9 μg/l for 100 days. when tadpoles were exposed to simazine at 11.0 and 100.9 µg/l, an increased mortality and damaged liver tissues were observed together with significant inhibition of ...201627485009
functional expression and characterization of plant abc transporters in xenopus laevis oocytes for transport engineering purposes.transport engineering in bioengineering is aimed at efficient export of the final product to reduce toxicity and feedback inhibition and to increase yield. the atp-binding cassette (abc) transporters with their highly diverse substrate specificity and role in cellular efflux are potentially suitable in transport engineering approaches, although their size and high number of introns make them notoriously difficult to clone. here, we report a novel in planta "exon engineering" strategy for cloning ...201627480688
a recurrent mutation in kcna2 as a novel cause of hereditary spastic paraplegia and ataxia.the hereditary spastic paraplegias (hsps) are heterogeneous neurodegenerative disorders with over 50 known causative genes. we identified a recurrent mutation in kcna2 (c.881g>a, p.r294h), encoding the voltage-gated k(+) -channel, kv 1.2, in two unrelated families with hsp, intellectual disability (id), and ataxia. follow-up analysis of > 2,000 patients with various neurological phenotypes identified a de novo p.r294h mutation in a proband with ataxia and id. two-electrode voltage-clamp recordin ...201627543892
gamma-tubulin coordinates nuclear envelope assembly around chromatin.the cytosolic role of γ-tubulin as a microtubule organizer has been studied thoroughly, but its nuclear function is poorly understood. here, we show that γ-tubulin is located throughout the chromatin of demembranated xenopus laevis sperm and, as the nucleus is formed, γ-tubulin recruits lamin b3 and nuclear membranes. immunodepletion of γ-tubulin impairs x. laevis assembly of both the lamina and the nuclear membrane. during nuclear formation in mammalian cell lines, γ-tubulin establishes a cellu ...201627699285
xenopus tacc2 is a microtubule plus end-tracking protein that can promote microtubule polymerization during embryonic development.microtubule dynamics is regulated by plus end-tracking proteins (+tips), which localize to the plus ends of microtubules (mts). we previously showed that tacc1 and tacc3, members of the transforming acidic coiled-coil protein family, can act as +tips to regulate mt dynamics in xenopus laevis here we characterize tacc2 as a +tip that localizes to mt plus ends in front of eb1 and overlapping with tacc1 and tacc3 in multiple embryonic cell types. we also show that tacc2 can promote mt polymerizatio ...201627559128
protein rs1 (rsc1a1) downregulates the exocytotic pathway of glucose transporter sglt1 at low intracellular glucose via inhibition of ornithine decarboxylase.na+-d-glucose cotransporter 1 (sglt1) is rate-limiting for glucose absorption in the small intestine. shortly after intake of glucose-rich food, sglt1 abundance in the luminal membrane of the small intestine is increased. this upregulation occurs via glucose-induced acceleration of the release of sglt1-containing vesicles from the trans-golgi network (tgn), which is regulated by a domain of protein rs1 (rsc1a1) named rs1-reg. dependent on phosphorylation, rs1-reg blocks release of vesicles conta ...201627555600
the aryl hydrocarbon receptor controls cyclin o to promote epithelial multiciliogenesis.epithelia function as barriers against environmental insults and express the transcription factor aryl hydrocarbon receptor (ahr). however, ahr function in these tissues is unknown. here we show that ahr regulates multiciliogenesis in both murine airway epithelia and in xenopus laevis epidermis. in air-exposed airway epithelia, induction of factors required for multiciliogenesis, including cyclin o (ccno) and multicilin (mcidas), is ahr dependent, and air exposure induces ahr binding to the ccno ...201627554288
thyroid hormone regulation of adult intestinal stem cells: implications on intestinal development and homeostasis.organ-specific adult stem cells are essential for organ homeostasis, tissue repair and regeneration. the formation of such stem cells often takes place during postembryonic development, a period around birth in mammals when plasma thyroid hormone concentration is high. the life-long self-renewal of the intestinal epithelium has made mammalian intestine a valuable model to study the function and regulation and adult stem cells. on the other hand, much less is known about how the adult intestinal ...201627554108
de novo and inherited mutations in the x-linked gene clcn4 are associated with syndromic intellectual disability and behavior and seizure disorders in males and females.variants in clcn4, which encodes the chloride/hydrogen ion exchanger cic-4 prominently expressed in brain, were recently described to cause x-linked intellectual disability and epilepsy. we present detailed phenotypic information on 52 individuals from 16 families with clcn4-related disorder: 5 affected females and 2 affected males with a de novo variant in clcn4 (6 individuals previously unreported) and 27 affected males, 3 affected females and 15 asymptomatic female carriers from 9 families wi ...201627550844
the proteins of vent-family and their mrnas are located in different areas of the tails of zebrafish and xenopus embryos.in molecular embryology, by tacit consent, a presence or absence of the specific mrna in the cell indicates the presence or absence of the corresponding protein. however, there are lots of evidences that mrna may be associated with inactive non-translated ribonucleoprotein complexes. here we for the first time compared the temporal and spatial distribution of the vent-family transcription factors and their mrnas in the tails of embryos of two biological species-xenopus laevis and zebrafish (dani ...201627620076
determining the optimal developmental stages of xenopus laevis for initiating exposures to chemicals for sensitively detecting their feminizing effects on gonadal differentiation.xenopus laevis is an important model for detecting feminizing effects of endocrine disrupting chemicals (edcs) on amphibians because its genetic males can be induced to phenotypic females by estrogenic chemicals. it is crucial that chemical exposures begin at sensitive developmental stages for gonadal sex-reversal in x. laevis. to determine the optimal stages for initiating exposures, we investigated gonadal sex-reversal induced by low concentrations of 17α-ethinylestradiol (ee2) when exposures ...201627611864
sequential turnovers of sex chromosomes in african clawed frogs (xenopus) suggest some genomic regions are good at sex determination.sexual differentiation is fundamentally important for reproduction, yet the genetic triggers of this developmental process can vary, even between closely related species. recent studies have uncovered, for example, variation in the genetic triggers for sexual differentiation within and between species of african clawed frogs (genus xenopus). here, we extend these discoveries by demonstrating that yet another sex determination system exists in xenopus, specifically in the species x. borealis this ...201627605520
reconstitution of the cytoplasmic regulation of the wnt signaling pathway using xenopus egg extracts.the regulation of β-catenin turnover is the central mechanism governing activation of the wnt signaling pathway. all components of the pathway are present in the early embryo of xenopus laevis, and xenopus egg extracts have been used to recapitulate complex biological reactions such as microtubule dynamics, dna replication, chromatin assembly, and phases of the cell cycle. herein, we describe a biochemical method for analyzing β-catenin degradation using radiolabeled and luciferase-fusion protei ...201627590156
mitochondrial trafficking through rhot1 is involved in the aggregation of germinal granule components during primordial germ cell formation in xenopus embryos.in many animals, the germ plasm is sufficient and necessary for primordial germ cell (pgc) formation. it contains germinal granules and abundant mitochondria (germline-mt). however, the role of germline-mt in germ cell formation remains poorly understood. in xenopus, the germ plasm is distributed as many small islands at the vegetal pole, which gradually aggregates to form a single large mass in each of the four vegetal pole cells at the early blastula stage. polymerized microtubules and the ada ...201627585825
a cell-free assay using xenopus laevis embryo extracts to study mechanisms of nuclear size regulation.a fundamental question in cell biology is how cell and organelle sizes are regulated. it has long been recognized that the size of the nucleus generally scales with the size of the cell, notably during embryogenesis when dramatic reductions in both cell and nuclear sizes occur. mechanisms of nuclear size regulation are largely unknown and may be relevant to cancer where altered nuclear size is a key diagnostic and prognostic parameter. in vivo approaches to identifying nuclear size regulators ar ...201627584618
functionomics of ncc mutations in gitelman syndrome using a novel mammalian cell-based activity assay.gitelman syndrome (gs) is an autosomal recessive salt-wasting tubular disorder resulting from loss-of-function mutations in the thiazide-sensitive nacl cotransporter (ncc). functional analysis of these mutations has been limited to the use of xenopus laevis oocytes. the aim of the present study was, therefore, to analyze the functional consequences of ncc mutations in a mammalian cell-based assay, followed by analysis of mutated ncc protein expression as well as glycosylation and phosphorylation ...201627582097
galvanic vestibular stimulation: cellular substrates and response patterns of neurons in the vestibulo-ocular network.galvanic vestibular stimulation (gvs) uses modulated currents to evoke neuronal activity in vestibular endorgans in the absence of head motion. gvs is typically used for a characterization of vestibular pathologies; for studies on the vestibular influence of gaze, posture, and locomotion; and for deciphering the sensory-motor transformation underlying these behaviors. at variance with the widespread use of this method, basic aspects such as the activated cellular substrate at the sensory periphe ...201627581452
microvascularization of the spleen in larval and adult xenopus laevis: histomorphology and scanning electron microscopy of vascular corrosion casts.microvascular anatomy and histomorphology of larval and adult spleens of the clawed toad, xenopus laevis were studied by light microscopy of paraplast embedded serial tissue sections and scanning electron microscopy (sem) of vascular corrosion casts (vccs). histology showed i) that white and red pulp are present at the onset of metamorphic climax (stage 57) and ii) that splenic vessels penetrated deeply into the splenic parenchyma at the height of metamorphic climax (stage 64). scanning electron ...201627581201
tbx3 represses bmp4 expression and, with pax6, is required and sufficient for retina formation.vertebrate eye formation begins in the anterior neural plate in the eye field. seven eye field transcription factors (eftfs) are expressed in eye field cells and when expressed together are sufficient to generate retina from pluripotent cells. the eftf tbx3 can regulate the expression of some eftfs; however, its role in retina formation is unknown. here, we show that tbx3 represses bmp4 transcription and is required in the eye field for both neural induction and normal eye formation in xenopus l ...201627578778
dissecting the pre-placodal transcriptome to reveal presumptive direct targets of six1 and eya1 in cranial placodes.the pre-placodal ectoderm, marked by the expression of the transcription factor six1 and its co-activator eya1, develops into placodes and ultimately into many cranial sensory organs and ganglia. using rna-seq in xenopus laevis we screened for presumptive direct placodal target genes of six1 and eya1 by overexpressing hormone-inducible constructs of six1 and eya1 in pre-placodal explants, and blocking protein synthesis before hormone-inducing nuclear translocation of six1 or eya1. comparing the ...201627576864
the lens regenerative competency of limbal vs. central regions of mature xenopus cornea epithelium.the frog, xenopus laevis, is capable of completely regenerating a lens from the cornea epithelium. because this ability appears to be limited to the larval stages of xenopus, virtually all the work to understand the mechanisms regulating this process has been limited to pre-metamorphic tadpoles. it has been reported that the post-metamorphic cornea is competent to regenerate under experimental conditions, despite the fact that the in vivo capacity to regenerate is lost; however, that work didn't ...201627569373
embryonic expression of endothelins and their receptors in lamprey and frog reveals stem vertebrate origins of complex endothelin signaling.neural crest cells (nccs) are highly patterned embryonic cells that migrate along stereotyped routes to give rise to a diverse array of adult tissues and cell types. modern nccs are thought to have evolved from migratory neural precursors with limited developmental potential and patterning. how this occurred is poorly understood. endothelin signaling regulates several aspects of ncc development, including their migration, differentiation, and patterning. in jawed vertebrates, endothelin signalin ...201627677704
gain-of-function defects of astrocytic kir4.1 channels in children with autism spectrum disorders and epilepsy.dysfunction of the inwardly-rectifying potassium channels kir4.1 (kcnj10) represents a pathogenic mechanism contributing to autism-epilepsy comorbidity. to define the role of kir4.1 variants in the disorder, we sequenced kcnj10 in a sample of affected individuals, and performed genotype-phenotype correlations. the effects of mutations on channel activity, protein trafficking, and astrocyte function were investigated in xenopus laevis oocytes, and in human astrocytoma cell lines. an in vivo model ...201627677466
expression of the insulinoma-associated 1 (insm1) gene in xenopus laevis tadpole retina and brain.the insulinoma-associated 1 (insm1) gene is involved in the differentiation of several neuronal and endoderm derived cell types. insm1 is expressed in the retina and brain of several vertebrates including xenopus laevis. we report the detailed expression pattern of insm1 in the x. laevis tadpole retina and brain. x. laevis insm1 is expressed in most of the ciliary marginal zone of the mature retina and the optic tectum, dorsal pallium, hypothalamus and preoptic areas of the developing tadpole br ...201627670931
chlorpyrifos exposure affects fgf8, sox9, and bmp4 expression required for cranial neural crest morphogenesis and chondrogenesis in xenopus laevis embryos.chlorpyrifos (cpf) is an organophosphate insecticide used primarily to control foliage and soil-borne insect pests on a variety of food and feed crops. in mammals, maternal exposure to cpf has been reported to induce dose-related abnormalities such as slower brain growth and cerebral cortex thinning. in lower vertebrates, for example, fish and amphibians, teratogenic activity of this compound is correlated with several anatomical alterations. little is known about the effects of cpf on mrna expr ...201627669663
the e3 ubiquitin ligase hace1 is required for early embryonic development in xenopus laevis.hect domain and ankyrin repeat containing e3 ubiquitin protein ligase 1 (hace1) regulates a wide variety of cellular processes. it has been shown that one of the targets of hace1 is the gtp-bound form of the small gtpase rac1. however, the role of hace1 in early development remains unknown.201627653971
overland movement in african clawed frogs (xenopus laevis): a systematic review.african clawed frogs (xenopus laevis) are often referred to as 'purely aquatic' but there are many publications which suggest extensive overland movements. previous reviews which considered the topic have not answered the following questions: (1) is there evidence for overland dispersal in native and invasive ranges; (2) what is the range of distances moved overland; (3) when does overland movement occur; and (4) is there evidence of breeding migratory behaviour? a systematic review was chosen t ...201627688972
thyroid hormone acts locally to increase neurogenesis, neuronal differentiation, and dendritic arbor elaboration in the tadpole visual system.thyroid hormone (th) regulates many cellular events underlying perinatal brain development in vertebrates. whether and how th regulates brain development when neural circuits are first forming is less clear. furthermore, although the molecular mechanisms that impose spatiotemporal constraints on th action in the brain have been described, the effects of local th signaling are poorly understood. we determined the effects of manipulating th signaling on development of the optic tectum in stage 46- ...201627707971
hdac3 but not hdac2 mediates visual experience-dependent radial glia proliferation in the developing xenopus tectum.radial glial cells (rgs) are one of the important progenitor cells that can differentiate into neurons or glia to form functional neural circuits in the developing central nervous system (cns). histone deacetylases (hdacs) has been associated with visual activity dependent changes in brdu-positive progenitor cells in the developing brain. we previously have shown that hdac1 is involved in the experience-dependent proliferation of rgs. however, it is less clear whether two other members of class ...201627729849
over 4100 protein identifications from a xenopus laevis fertilized egg digest using reversed-phase chromatographic prefractionation followed by capillary zone electrophoresis-electrospray ionization-tandem mass spectrometry analysis.a tryptic digest generated from xenopus laevis fertilized embryos was fractionated by rplc. one set of 30 fractions was analyzed by 100-min cze-esi-ms/ms separations (50 h total instrument time), and a second set of 15 fractions was analyzed by 3-h uplc-esi-ms/ms separations (45 h total instrument time). cze-ms/ms produced 70% as many protein ids (4134 versus 5787) and 60% as many peptide ids (22 535 versus 36 848) as uplc-ms/ms with similar instrument time (50 h versus 45 h) but with 50 times s ...201627723263
pathogenic variants in kctd7 perturb neuronal k+ fluxes and glutamine transport.progressive myoclonus epilepsy is a heterogeneous group of disorders characterized by myoclonic and tonic-clonic seizures, ataxia and cognitive decline. we here present two affected brothers. at 9 months of age the elder brother developed ataxia and myoclonic jerks. in his second year he lost the ability to walk and talk, and he developed drug-resistant progressive myoclonus epilepsy. the cerebrospinal fluid level of glutamate was decreased while glutamine was increased. his younger brother mani ...201627742667
adaption of a dermal in vitro method to investigate the uptake of chemicals across amphibian skin.literature data indicate that terrestrial life stages of amphibians may be more sensitive to xenobiotics than birds or mammals. it is hypothesized that dermal exposure could potentially be a significant route of exposure for amphibians, as there is evidence that their skin is more permeable than the skin of other vertebrate species. thus, higher amounts of xenobiotics might enter systemic circulation by dermal uptake resulting in adverse effects. heretofore, no guidelines exist to investigate de ...201627752445
chromatin assembly and transcriptional cross-talk in xenopus laevis oocyte and egg extracts.chromatin, primarily a complex of dna and histone proteins, is the physiological form of the genome. chromatin is generally repressive for transcription and other information transactions that occur on dna. a wealth of post-translational modifications on canonical histones and histone variants encode regulatory information to recruit or repel effector proteins on chromatin, promoting and further repressing transcription and thereby form the basis of epigenetic information. during metazoan oogene ...201627759158
flexibility vs. robustness in cell cycle regulation of timing of m-phase entry in xenopus laevis embryo cell-free extract.during the cell cycle, cyclin dependent kinase 1 (cdk1) and protein phosphatase 2a (pp2a) play major roles in the regulation of mitosis. cdk1 phosphorylates a series of substrates triggering m-phase entry. most of these substrates are dephosphorylated by pp2a. to allow phosphorylation of cdk1 substrates, pp2a is progressively inactivated upon m-phase entry. we have shown previously that the interplay between these two activities determines the timing of m-phase entry. slight diminution of cdk1 a ...201627759157
chaperone-mediated chromatin assembly and transcriptional regulation in xenopus laevis.chromatin is the complex of dna and histone proteins that is the physiological form of the eukaryotic genome. chromatin is generally repressive for transcription, especially so during early metazoan development when maternal factors are explicitly in control of new zygotic gene expression. in the important model organism xenopus laevis, maturing oocytes are transcriptionally active with reduced rates of chromatin assembly, while laid eggs and fertilized embryos have robust rates of chromatin ass ...201627759155
aurora-a: an expedition to the pole of the spindle in xenopus egg extracts.the aim of this short review is to describe the contribution of xenopus laevis egg extracts to the discovery and understanding of the regulation and function of the serine/threonine kinase aurora-a. the power of these extracts to recapitulate cell cycle events makes them a precious tool to decipher complex biological processes at the molecular level, including the mechanisms that affect aurora-a (post-translational modifications) and mechanisms in which aurora-a plays a crucial role (bipolar spi ...201627759154
studying essential dna metabolism proteins in xenopus egg extract.the correct duplication of genetic information is essential to maintain genome stability, which is lost in cancer cells. replication fork integrity is ensured by a number of dna metabolism proteins that assist replication of chromatin regions difficult to replicate due to their intrinsic dna sequence composition, coordinate repair of dna molecules resulting from aberrant replication events or protect replication forks in the presence of lesions impairing their progression. some dna metabolism ge ...201627759152
two light-activated neuroendocrine circuits arising in the eye trigger physiological and morphological pigmentation.two biological processes regulate light-induced skin colour change. a fast 'physiological pigmentation change' (i.e. circadian variations or camouflage) involves alterations in the distribution of pigment containing granules in the cytoplasm of chromatophores, while a slower 'morphological pigmentation change' (i.e. seasonal variations) entails changes in the number of pigment cells or pigment type. although linked processes, the neuroendocrine coordination triggering each response remains large ...201627557040
ubiquitin-mediated proteolysis in xenopus extract.the small protein modifier, ubiquitin, can be covalently attached to proteins in the process of ubiquitylation, resulting in a variety of functional outcomes. in particular, the most commonly-associated and well-studied fate for proteins modified with ubiquitin is their ultimate destruction: degradation by the 26s proteasome via the ubiquitin-proteasome system, or digestion in lysosomes by proteolytic enzymes. from the earliest days of ubiquitylation research, a reliable and versatile "cell-in-a ...201627528041
reprogramming of somatic cells and nuclei by xenopus oocyte and egg extracts.differentiated somatic cells and nuclei can be reprogrammed to a pluripotent undifferentiated state in the cytoplasm of oocytes and eggs. the ability of the gamete cells to induce reprogramming is not species-specific, so the extracts prepared from the oocytes and eggs of the african clawed frog xenopus laevis can reprogram somatic mammalian cells. thus, xenopus egg extract-mediated reprogramming may constitute an alternative or complement other experimental reprogramming approaches, such as nuc ...201627251073
cell-free xenopus egg extracts for studying dna damage response pathways.in response to a variety of dna replication stress or dna damaging agents, the dna damage response (ddr) pathways are triggered for cells to coordinate dna repair, cell cycle checkpoints, apoptosis, and senescence. cell-free xenopus egg extracts, derived from the eggs of african clawed frogs (xenopus laevis), have been widely used for studies concerning ddr pathways. in this review, we focus on how different experimental systems have been established using xenopus egg extracts to investigate the ...201627160070
novel kcnq3 mutation in a large family with benign familial neonatal epilepsy: a rare cause of neonatal seizures.benign familial neonatal seizures (bfns) present a rare familial epilepsy syndrome caused by genetic alterations in the voltage-gated potassium channels kv7.2 and kv7.3, encoded by kcnq2 and kcnq3. while most bfns families carry alterations in kcnq2, mutations in kcnq3 appear to be less common. here, we describe a family with 6 individuals presenting with neonatal focal and generalized seizures. genetic testing revealed a novel kcnq3 variant, c.835g>t, cosegregating with seizures in 4 tested ind ...201627781029
spatiotemporal development of the orexinergic (hypocretinergic) system in the central nervous system of xenopus laevis.the present immunohistochemical study represents a detailed spatiotemporal analysis of the localization of orexin-immunoreactive (ox-ir) cells and fibers throughout development in the brain of the anuran amphibian xenopus laevis, a model frequently used in developmental studies. anurans undergo remarkable physiological changes during the early life stages, and very little is known about the ontogeny and the localization of the centers that control functions such as appetite and feed ingestion in ...201627771730
p,p'-dichlordiphenyldichloroethylene (p,p'-dde) can elicit antiandrogenic and estrogenic modes of action in the amphibian xenopus laevis.p,p'-dichlordiphenyldichloroethylene (dde) is a metabolite of the insecticide dichlorodiphenyltrichloroethane (ddt), an organochloride which was massively used from its discovery in 1939 until the early 1970's. due to the tremendous half-life of ddt and dde, both substances are to date environmentally relevant. furthermore, ddt is still employed in many african countries in the context of the who's antimalaria campaign. in amphibians, dde was found to act as antiandrogenic endocrine disrupting c ...201627640133
mechanism of antineoplastic activity of lonidamine.lonidamine (lnd) was initially introduced as an antispermatogenic agent. it was later found to have anticancer activity sensitizing tumors to chemo-, radio-, and photodynamic-therapy and hyperthermia. although the mechanism of action remained unclear, lnd treatment has been known to target metabolic pathways in cancer cells. it has been reported to alter the bioenergetics of tumor cells by inhibiting glycolysis and mitochondrial respiration, while indirect evidence suggested that it also inhibit ...201627497601
genome evolution in the allotetraploid frog xenopus laevis.to explore the origins and consequences of tetraploidy in the african clawed frog, we sequenced the xenopus laevis genome and compared it to the related diploid x. tropicalis genome. we characterize the allotetraploid origin of x. laevis by partitioning its genome into two homoeologous subgenomes, marked by distinct families of 'fossil' transposable elements. on the basis of the activity of these elements and the age of hundreds of unitary pseudogenes, we estimate that the two diploid progenitor ...201627762356
high-sensitivity mass spectrometry for probing gene translation in single embryonic cells in the early frog (xenopus) embryo.direct measurement of protein expression with single-cell resolution promises to deepen the understanding of the basic molecular processes during normal and impaired development. high-resolution mass spectrometry provides detailed coverage of the proteomic composition of large numbers of cells. here we discuss recent mass spectrometry developments based on single-cell capillary electrophoresis that extend discovery proteomics to sufficient sensitivity to enable the measurement of proteins in sin ...201627761436
one special glomerulus in the olfactory bulb of xenopus laevis tadpoles integrates a broad range of amino acids and mechanical stimuli.the olfactory system senses odors, but not exclusively, as shown over the past years. it also registers other modalities such as temperature and pressure. however, it remains unknown how widespread these sensitivities are across species and how strongly their processing is interconnected with the processing of odors. here, we present data on the β-glomerulus in the olfactory bulb of xenopus laevis tadpoles. we show that this glomerulus possesses an unusually broad response pattern to a large num ...201627798179
effects of the biocide methylisothiazolinone on xenopus laevis wound healing and tail regeneration.the south african clawed frog, xenopus laevis, has a strong history as a suitable model for environmental studies. its embryos and transparent tadpoles are highly sensitive to the environment and their developmental processes are well described. it is also amenable for molecular studies. these characteristics enable its use for rapid identification and understanding of exposure-induced defects. to investigate the consequences of chemical exposure on aquatic animals, xenopus laevis embryos and ta ...201627810491
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