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high-throughput analysis reveals novel maternal germline rnas crucial for primordial germ cell preservation and proper migration.during oogenesis, hundreds of maternal rnas are selectively localized to the animal or vegetal pole, including determinants of somatic and germline fates. although microarray analysis has identified localized determinants, it is not comprehensive and is limited to known transcripts. here, we utilized high-throughput rna-sequencing analysis to comprehensively interrogate animal and vegetal pole rnas in the fully grown xenopus laevis oocyte. we identified 411 (198 annotated) and 27 (15 annotated) ...201728096217
folate receptor 1 is necessary for neural plate cell apical constriction during xenopus neural tube formation.folate supplementation prevents up to 70% of neural tube defects (ntds), which result from a failure of neural tube closure during embryogenesis. the elucidation of the mechanisms underlying folate action has been challenging. this study introduces xenopus laevis as a model to determine the cellular and molecular mechanisms involved in folate action during neural tube formation. we show that knockdown of folate receptor 1 (folr1; also known as frα) impairs neural tube formation and leads to ntds ...201728255006
optimization of the t3-induced xenopus metamorphosis assay for detecting thyroid hormone signaling disruption of chemicals.t3-induced xenopus metamorphosis is an ideal model for detecting thyroid hormone (th) signaling disruption of chemicals. to optimize the t3-induced xenopus assay and improve its sensitivity and reproducibility, we intend to develop quantitatively morphological endpoints and choose appropriate concentrations and exposure durations for t3 induction. xenopus laevis at stage 52 were exposed to series of concentrations of t3 (0.31-2.5nmol/l) for 6days. by comparing morphological changes induced by t3 ...201728254053
role of cdc6 during oogenesis and early embryo development in mouse and xenopus laevis.cdc6 is an important player in cell cycle regulation. it is involved in the regulation of both s-phase and m-phase. its role during oogenesis is crucial for repression of the s-phase between the first and the second meiotic m-phases, and it also regulates, via cdk1 inhibition, the m-phase entry and exit. this is of special importance for the reactivation of the major m-phase-regulating kinase cdk1 (cyclin-dependent kinase 1) in oocytes entering metaphase ii of meiosis and in embryo cleavage divi ...201728247050
xenopus as a model for studies in mechanical stress and cell division.we exist in a physical world, and cells within biological tissues must respond appropriately to both environmental forces and forces generated within the tissue to ensure normal development and homeostasis. cell division is required for normal tissue growth and maintenance, but both the direction and rate of cell division must be tightly controlled to avoid diseases of over-proliferation such as cancer. recent studies have shown that mechanical cues can cause mitotic entry and orient the mitotic ...201728095623
tools for live imaging of active rho gtpases in xenopus.rho family gtpases are signaling molecules that orchestrate cytoskeletal dynamics in a variety of cellular processes. because they effect localized changes to the cytoskeleton only in their active (gtp-bound) conformation, the ability to monitor the active state of rho gtpases in space and time is critical for understanding their function. here, we summarize popular tools used for live imaging of active rho gtpases, outlining advantages and drawbacks of these approaches. additionally, we highlig ...201728095620
visual experience dependent regulation of neuronal structure and function by histone deacetylase 1 in developing xenopus tectum in vivo.histone deacetylase 1 (hdac1) is thought to play pivotal roles in neurogenesis and neurodegeneration. however, the role of hdac1 in neuronal growth and structural plasticity in the developing brain in vivo remains unclear. here, we show that in the optic tectum of xenopus laevis, hdac1 knockdown dramatically decreased the frequency of ampar-mediated synaptic currents and increased the frequency of gabaar-mediated currents, whereas hdac1 overexpression significantly decreased the frequency of gab ...201728033671
xenopus laevis as a model system to study cytoskeletal dynamics during axon pathfinding.the model system, xenopus laevis, has been used in innumerable research studies and has contributed to the understanding of multiple cytoskeletal components, including actin, microtubules, and neurofilaments, during axon pathfinding. xenopus developmental stages have been widely characterized, and the xenopus genome has been sequenced, allowing gene expression modifications through exogenous molecules. xenopus cell cultures are ideal for long periods of live imaging because they are easily obtai ...201728095612
quantifying the relative contributions of different solute carriers to aggregate substrate transport.determining the contributions of different transporter species to overall cellular transport is fundamental for understanding the physiological regulation of solutes. we calculated the relative activities of solute carrier (slc) transporters using the michaelis-menten equation and global fitting to estimate the normalized maximum transport rate for each transporter (vmax). data input were the normalized measured uptake of the essential neutral amino acid (aa) l-leucine (leu) from concentration-d ...201728091567
high variability of expression profiles of homeologous genes for wnt, hh, notch, and hippo signaling pathways in xenopus laevis.cell signaling pathways, such as wnt, hedgehog (hh), notch, and hippo, are essential for embryogenesis, organogenesis, and tissue homeostasis. in this study, we analyzed 415 genes involved in these pathways in the allotetraploid frog, xenopus laevis. most genes are retained in two subgenomes called l and s (193 homeologous gene pairs and 29 singletons). this conservation rate of homeologs is much higher than that of all genes in the x. laevis genome (86.9% vs 60.2%). among singletons, 24 genes a ...201728089430
the amino acid transporter, slc1a3, is plasma membrane-localised in adipocytes and its activity is insensitive to insulin.the hormone insulin coordinates the catabolism of nutrients by protein phosphorylation. phosphoproteomic analysis identified insulin-responsive phosphorylation of the glu/asp transporter slc1a3/eaat1 in adipocytes. the role of slc1a3 in adipocytes is not well-understood. we show that slc1a3 is localised to the plasma membrane and the major regulator of acidic amino acid uptake in adipocytes. however, its localisation and activity were unaffected by insulin or mutation of the insulin-regulated ph ...201728032905
human neuronal calcium sensor-1 protein avoids histidine residues to decrease ph sensitivity.ph is highly regulated in mammalian central nervous systems. neuronal calcium sensor-1 (ncs-1) can interact with numerous target proteins. compared to that in the ncs-1 protein of caenorhabditis elegans, evolution has avoided the placement of histidine residues at positions 102 and 83 in the ncs-1 protein of humans and xenopus laevis, possibly to decrease the conformational sensitivity to ph gradients in synaptic processes. we used all-atom molecular dynamics simulations to investigate the effec ...201728030949
evolution of vocal patterns: tuning hindbrain circuits during species divergence.the neural circuits underlying divergent courtship behaviors of closely related species provide a framework for insight into the evolution of motor patterns. in frogs, male advertisement calls serve as unique species identifiers and females prefer conspecific to heterospecific calls. advertisement calls of three relatively recently (∼8.5 mya) diverged species - xenopus laevis, x. petersii and x. victorianus - include rapid trains of sound pulses (fast trills). we show that while fast trills are ...201728011819
molecular cloning and functional expression of the k+ channel kv7.1 and the regulatory subunit kcne1 from equine myocardium.the voltage-gated k+-channel kv7.1 and the subunit kcne1, encoded by the kcnq1 and kcne1 genes, respectively, are responsible for termination of the cardiac action potential. in humans, mutations in these genes can predispose patients to arrhythmias and sudden cardiac death (scd).201728917093
hmmr mediates anterior neural tube closure and morphogenesis in the frog xenopus.development of the central nervous system requires orchestration of morphogenetic processes which drive elevation and apposition of the neural folds and their fusion into a neural tube. the newly formed tube gives rise to the brain in anterior regions and continues to develop into the spinal cord posteriorly. conspicuous differences between the anterior and posterior neural tube become visible already during neural tube closure (ntc). planar cell polarity (pcp)-mediated convergent extension (ce) ...201728778799
combining cytotoxicity assessment and xenopus laevis phenotypic abnormality assay as a predictor of nanomaterial safety.the african clawed frog, xenopus laevis, has been used as an efficient pre-clinical screening tool to predict drug safety during the early stages of the drug discovery process. x. laevis is a relatively inexpensive model that can be used in whole organism high-throughput assays whilst maintaining a high degree of homology to the higher vertebrate models often used in scientific research. despite an ever-increasing volume of biomedical nanoparticles (nps) in development, their unique physico-chem ...201728777439
loss of fourth electron-transferring tryptophan in animal (6-4) photolyase impairs dna repair activity in bacterial cells.(6-4) photolyases [(6-4)pls] are flavoproteins that use blue light to repair the ultraviolet-induced pyrimidine(6-4)pyrimidone photoproduct in dna. their flavin adenine dinucleotide (fad) cofactor can be reduced to its repair-active fadh- form by a photoinduced electron transfer reaction. in animal (6-4)pls, a chain of four trp residues was suggested to be involved in a stepwise transfer of an oxidation hole from the flavin to the surface of the protein. here, we investigated the effect of mutat ...201728880077
organ culture of the xenopus tadpole intestine.during xenopus metamorphosis, most tadpole organs remodel from the larval to adult form to prepare for adaptation to terrestrial life. organ culture serves as an important tool for studying larval-to-adult organ remodeling independent of the effects of other parts of the body. here, i introduce a protocol for organ culture in vitro using the xenopus laevis tadpole intestine before metamorphic climax. during culture in the absence of exogenous 3,3',5-triiodo-l-thyronine (t3), the most potent natu ...201728912375
smarcal1-mediated fork reversal triggers mre11-dependent degradation of nascent dna in the absence of brca2 and stable rad51 nucleofilaments.brca2 deficiency causes mre11-dependent degradation of nascent dna at stalled forks, leading to cell lethality. to understand the molecular mechanisms underlying this process, we isolated xenopus laevis brca2. we demonstrated that brca2 protein prevents single-stranded dna gap accumulation at replication fork junctions and behind them by promoting rad51 binding to replicating dna. without brca2, forks with persistent gaps are converted by smarcal1 into reversed forks, triggering extensive mre11- ...201728757209
fetax assay for evaluation of developmental toxicity.the frog embryo teratogenesis assay xenopus (fetax) test is a development toxicity screening test. due to the small amount of compound needed and the capability to study organogenesis in a short period of time (96 h), fetax test constitutes an efficient development toxicity alert test when performed early in drug safety development. the test is conducted on fertilized xenopus laevis mid-blastula-stage eggs over the organogenesis period. compound teratogenic potential is determined after analysis ...201728748472
xenopus laevis m18bp1 directly binds existing cenp-a nucleosomes to promote centromeric chromatin assembly.vertebrate centromeres are epigenetically defined by nucleosomes containing the histone h3 variant, cenp-a. cenp-a nucleosome assembly requires the three-protein mis18 complex (mis18α, mis18β, and m18bp1) that recruits the cenp-a chaperone hjurp to centromeres, but how the mis18 complex recognizes centromeric chromatin is unknown. using xenopus egg extract, we show that direct, cell-cycle-regulated binding of m18bp1 to cenp-a nucleosomes recruits the mis18 complex to interphase centromeres to pr ...201728743005
dual control of pcdh8l/pcns expression and function in xenopus laevis neural crest cells by adam13/33 via the transcription factors tfap2α and arid3a.adam13/33 is a cell surface metalloprotease critical for cranial neural crest (cnc) cell migration. it can cleave multiple substrates including itself, fibronectin, ephrinb, cadherin-11, pcdh8 and pcdh8l (this work). cleavage of cadherin-11 produces an extracellular fragment that promotes cnc migration. in addition, the adam13 cytoplasmic domain is cleaved by gamma secretase, translocates into the nucleus and regulates multiple genes. here, we show that adam13 interacts with the arid3a/dril1/bri ...201728829038
assembly rules for gabaa receptor complexes in the brain.gabaa receptor (gabaar) pentamers are assembled from a pool of 19 subunits, and variety in subunit combinations diversifies gabaar functions to tune brain activity. pentamers with distinct subunit compositions localize differentially at synaptic and non-synaptic sites to mediate phasic and tonic inhibition, respectively. despite multitudes of theoretical permutations, limited subunit combinations have been identified in the brain. currently, no molecular model exists for combinatorial gabaar ass ...201728816653
histone methyltransferase dot1l is a coactivator for thyroid hormone receptor during xenopus development.histone modifications are associated with transcriptional regulation by diverse transcription factors. genome-wide correlation studies have revealed that histone activation marks and repression marks are associated with activated and repressed gene expression, respectively. among the histone activation marks is histone h3 k79 methylation, which is carried out by only a single methyltransferase, disruptor of telomeric silencing-1-like (dot1l). we have been studying thyroid hormone (t3)-dependent ...201728739643
splice variants of ph-sensitive chloride channel identify a key determinant of ivermectin sensitivity in the larvae of the silkworm bombyx mori.the ph-sensitive chloride channels (phcls) are broadly expressed in insects, but little is known about their physiologic role, diversity, and sensitivity to insecticides acting on relevant chloride channels. here we have sequenced 50 transcripts of the phcl-1 gene from the brain, third thoracic ganglion (t3g), and midgut of larvae of silkworm bombyx mori it was found that >50 variants were expressed with distinct splicing in the t3g compared with the brain and midgut. of the variants detected, v ...201728739571
a g326e substitution in the glutamate-gated chloride channel 3 (glucl3) of the two-spotted spider mite tetranychus urticae abolishes the agonistic activity of macrocyclic lactones.the macrocyclic lactones abamectin and milbemectin are frequently used to control phytophagous mites such as tetranychus urticae. consequently, resistance has developed and was genetically linked with substitutions in the glutamate-gated chloride channel (glucl) subunits tuglucl1 and tuglucl3. here, we functionally validated a g326e substitution in tuglucl3 by functional expression in xenopus laevis oocytes followed by two-electrode voltage-clamp electrophysiology.201728736919
neuronal degeneration and regeneration induced by axotomy in the olfactory epithelium of xenopus laevis.the olfactory epithelium (oe) has the remarkable capability to constantly replace olfactory receptor neurons (orns) due to the presence of neural stem cells (nscs). for this reason, the oe provides an excellent model to study neurogenesis and neuronal differentiation. in the present work, we induced neuronal degeneration in the oe of xenopus laevis larvae by bilateral axotomy of the olfactory nerves. we found that axotomy induces specific- neuronal death through apoptosis between 24 and 48h post ...201728719101
a functional approach to understanding the role of nckx5 in xenopus pigmentation.nckx5 is an ion exchanger expressed mostly in pigment cells; however, the functional role for this protein in melanogenesis is not clear. a variant allele of slc24a5, the gene encoding nckx5, has been shown to correlate with lighter skin pigmentation in humans, indicating a key role for slc24a5 in determining human skin colour. slc24a5 expression has been found to be elevated in melanoma. knockdown analyses have shown slc24a5 to be important for pigmentation, but to date the function of this ion ...201728692664
lethal digenic mutations in the k+ channels kir4.1 (kcnj10) and slack (kcnt1) associated with severe-disabling seizures and neurodevelopmental delay.a 2-yr-old boy presented profound developmental delay, failure to thrive, ataxia, hypotonia, and tonic-clonic seizures that caused the death of the patient. targeted and whole exome sequencing revealed two heterozygous missense variants: a novel mutation in the kcnj10 gene that encodes for the inward-rectifying k+ channel kir4.1 and another previously characterized mutation in kcnt1 that encodes for the na+-activated k+ channel known as slo2.2 or slack. the objectives of this study were to perfo ...201728747464
tonoplast-localized nitrate uptake transporters involved in vacuolar nitrate efflux and reallocation in arabidopsis.a great proportion of nitrate taken up by plants is stored in vacuoles. vacuolar nitrate accumulation and release is of great importance to nitrate reallocation and efficient utilization. however, how plants mediate nitrate efflux from vacuoles to cytoplasm is largely unknown. the current study identified npf5.11, npf5.12 and npf5.16 as vacuolar nitrate efflux transporters in arabidopsis. histochemical analysis showed that npf5.11, npf5.12 and npf5.16 were expressed preferentially in root pericy ...201728743909
both nuclear size and dna amount contribute to midblastula transition timing in xenopus laevis.during early xenopus laevis embryogenesis both nuclear and cell volumes decrease with the nuclear-to-cytoplasmic (n/c) volume ratio reaching a maximum at the midblastula transition (mbt). at the mbt, embryonic transcription is upregulated and cell cycles lengthen. early studies demonstrated a role for the dna-to-cytoplasmic ratio in the control of mbt timing. by altering nuclear size, we previously showed that the n/c volume ratio also contributes to proper mbt timing. here we examine the relati ...201728801588
role of aqp9 in transport of monomethyselenic acid and selenite.aqp9 is an aquaglyceroporin with a very broad substrate spectrum. in addition to its orthodox nutrient substrates, aqp9 also transports multiple neutral and ionic arsenic species including arsenic trioxide, monomethylarsenous acid (masiii) and dimethylarsenic acid (dmav). here we discovered a new group of aqp9 substrates which includes two clinical relevant selenium species. we showed that aqp9 efficiently transports monomethylselenic acid (msea) with a preference for acidic ph, which has been d ...201728798983
fluorescence correlation spectroscopy experiments to quantify free diffusion coefficients in reaction-diffusion systems: the case of ca^{2+} and its dyes.many cell signaling pathways involve the diffusion of messengers that bind and unbind to and from intracellular components. quantifying their net transport rate under different conditions then requires having separate estimates of their free diffusion coefficient and binding or unbinding rates. in this paper, we show how performing sets of fluorescence correlation spectroscopy (fcs) experiments under different conditions, it is possible to quantify free diffusion coefficients and on and off rate ...201728709293
regulation of the insulin-akt signaling pathway and glycolysis during dehydration stress in the african clawed frog xenopus laevis.estivation is an adaptive stress response utilized by some amphibians during periods of drought in the summer season. in this study, we examine the regulation of the insulin signaling cascade and glycolysis pathway in the african clawed frog xenopus laevis during the dehydration stress induced state of estivation. we show that in the brain and heart of x. laevis, dehydration reduces the phosphorylation of the insulin growth factor-1 receptor (igf-1r), and this is followed by similar reductions i ...201728708941
coordinating heart morphogenesis: a novel role for hyperpolarization-activated cyclic nucleotide-gated (hcn) channels during cardiogenesis in xenopus laevis.hyperpolarization-activated cyclic-nucleotide gated channel (hcn) proteins are important regulators of both neuronal and cardiac excitability. among the 4 hcn isoforms, hcn4 is known as a pacemaker channel, because it helps control the periodicity of contractions in vertebrate hearts. although the physiological role of hcn4 channel has been studied in adult mammalian hearts, an earlier role during embryogenesis has not been clearly established. here, we probe the embryonic roles of hcn4 channels ...201728702127
charged antimicrobial peptides can translocate across membranes without forming channel-like pores.how can highly charged, cationic antimicrobial peptides (amps) translocate across hydrophobic lipid bilayers despite the prohibitive energetic penalty to do so? a common explanation has been the formation of peptide-lined channels. however, for most amps, no structures of membrane pores have been found despite clear evidence of membrane leakage and antimicrobial activity. the study here suggests an alternative and simple reason: for the amp pgla from xenopus laevis (charge +5), such pores are no ...201728700927
chk1 inhibition of the replication factor drf1 guarantees cell-cycle elongation at the xenopus laevis mid-blastula transition.the early cell divisions of many metazoan embryos are rapid and occur in the near absence of transcription. at the mid-blastula transition (mbt), the cell cycle elongates and several processes become established including the onset of bulk transcription and cell-cycle checkpoints. how these events are timed and coordinated is poorly understood. here we show in xenopus laevis that developmental activation of the checkpoint kinase chk1 at the mbt results in the scfβ-trcp-dependent degradation of a ...201728697335
high-efficiency non-mosaic crispr-mediated knock-in and indel mutation in f0 xenopus.the revolution in crispr-mediated genome editing has enabled the mutation and insertion of virtually any dna sequence, particularly in cell culture where selection can be used to recover relatively rare homologous recombination events. the efficient use of this technology in animal models still presents a number of challenges, including the time to establish mutant lines, mosaic gene editing in founder animals, and low homologous recombination rates. here we report a method for crispr-mediated g ...201728694259
in vivo analysis of the neurovascular niche in the developing xenopus brain.the neurovascular niche is a specialized microenvironment formed by the interactions between neural progenitor cells (npcs) and the vasculature. while it is thought to regulate adult neurogenesis by signaling through vascular-derived soluble cues or contacted-mediated cues, less is known about the neurovascular niche during development. in xenopus laevis tadpole brain, npcs line the ventricle and extend radial processes tipped with endfeet to the vascularized pial surface. using in vivo labeling ...201728795134
comprehensive analyses of hox gene expression in xenopus laevis embryos and adult tissues.from whole genome sequencing of an allotetraploid frog, xenopus laevis, two homeologous sets (l and s) of four hox clusters a through d (hoxa.l/s, hoxb.l/s, hoxc.l/s, and hoxd.l/s) and 13 paralogous groups (pgs) with 76 genes were identified, allowing us to carry out the first comprehensive analyses of hox gene expression in vertebrates. expression of all hox genes during development and in adult tissues was analyzed by rna-sequencing. the expression levels of most hox genes were similar between ...201728791673
renal localization and regulation by dietary phosphate of the mct14 orphan transporter.mct14 is an orphan transporter belonging to the slc16 transporter family mediating the transport of monocarboxylates, aromatic amino acids, creatine, and thyroid hormones. the expression, tissue localization, regulation, and function of mct14 are unknown. in mouse mct14 mrna abundance is highest in kidney. using a newly developed and validated antibody, mct14 was localized to the luminal membrane of the thick ascending limb of the loop of henle colocalizing in the same cells with uromodulin and ...201728662032
family of ricinus communis monosaccharide transporters and rcstp1 in promoting the uptake of a glucose-fipronil conjugate.enhancing the systemic distribution of a bioactive compound by exploiting the vascular transport system of a plant presents a means of reducing both the volume and frequency of pesticide/fungicide application. the foliar uptake of the glucose-fipronil conjugate n-[3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1h-pyrazol-5-yl]-1-(β-d-glucopyranosyl)-1h-1,2,3-triazole-4-methanamine (gtf) achieved in castor bean (ricinus communis) and its transport via the phloem ...201728692262
a method for detailed movement pattern analysis of tadpole startle response.prolonged space flight, specifically microgravity, presents a problem for space exploration. animal models with altered connections of the vestibular ear, and thus altered gravity sensation, would allow the examination of the effects of microgravity and how various countermeasures can establish normal function. we describe an experimental apparatus to monitor the effects of ear manipulations to generate asymmetric gravity input on the tadpole escape response. to perform the movement pattern anal ...201728653338
the cannabinoid receptor interacting proteins 1 of zebrafish are not required for morphological development, viability or fertility.the cannabinoid receptor interacting protein 1 (cnrip1) was discovered as an interactor with the intracellular region of cannabinoid receptor 1 (cb1r, also known as cnr1 or cb1). functional assays in mouse show cannabinoid sensitivity changes and cnrip1 has recently been suggested to control eye development in xenopus laevis. two cnrip1 genes are described in zebrafish, cnrip1a and cnrip1b. in situ mrna hybridisation revealed accumulation of mrna encoding each gene primarily in brain and spinal ...201728687732
acetylcholinesterase plays a non-neuronal, non-esterase role in organogenesis.acetylcholinesterase (ache) is crucial for degrading acetylcholine at cholinergic synapses. in vitro studies suggest that, in addition to its role in nervous system signaling, ache can also modulate non-neuronal cell properties, although it remains controversial whether ache functions in this capacity in vivo here, we show that ache plays an essential non-classical role in vertebrate gut morphogenesis. exposure of xenopus embryos to ache-inhibiting chemicals results in severe defects in intestin ...201728684626
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 ...201727016259
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- ...201727063898
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 ...201727063102
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 ...201726993591
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 ...201727099217
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 ...201726430383
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 ...201728630098
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 ...201729205924
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 ...201728768767
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 ...201728775717
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 ...201728769947
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 ...201728858240
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 ...201728749993
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.201728752787
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 ...201727741560
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 ...201728746452
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. ...201727927791
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 ...201728504275
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 ...201729094344
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 ...201727644024
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. ...201729218708
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 ...201727785717
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 ...201728095648
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 ...201723473789
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 ...201727381278
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 ...201728784850
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 ...201728503895
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.201729266590
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 ...201729246943
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 ...201729263320
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 ...201729218002
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 ...201729223796
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 ...201728439068
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 ...201728545147
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 ...201728439453
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 ...201729326551
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 ...201728100805
maitotoxin is a potential selective activator of the endogenous transient receptor potential canonical type 1 channel in xenopus laevis oocytes.maitotoxin (mtx) is the most potent marine toxin known to date. it is responsible for a particular human intoxication syndrome called ciguatera fish poisoning (cfp). several reports indicate that mtx is an activator of non-selective cation channels (nscc) in different cell types. the molecular identity of these channels is still an unresolved topic, and it has been proposed that the transient receptor potential (trp) channels are involved in this effect. in xenopus laevis oocytes, mtx at picomol ...201728672825
the tyrosine y2502.39 in frizzled 4 defines a conserved motif important for structural integrity of the receptor and recruitment of disheveled.frizzleds (fzds) are unconventional g protein-coupled receptors, which activate diverse intracellular signaling pathways via the phosphoprotein disheveled (dvl) and heterotrimeric g proteins. the interaction interplay of fzds with dvl and g proteins is complex, involves different regions of fzd and the potential dynamics are poorly understood. in the present study, we aimed to characterize the function of a highly conserved tyrosine (y2502.39) in the intracellular loop 1 (il1) of human fzd4. we ...201728668722
developmental neurogenesis in mouse and xenopus is impaired in the absence of nosip.genetic deletion of nosip in mice causes holoprosencephaly, however, the function of nosip in neurogenesis is currently unknown.201728663132
a multi-tiered, in vivo, quantitative assay suite for environmental disruptors of thyroid hormone signaling.the essential role of thyroid hormone (th) signaling in mammalian development warrants the examination of man-made chemicals for its disruption. among vertebrate species, the molecular components of th signaling are highly conserved, including the thyroid hormone receptors (trs), their heterodimer binding partners the retinoid-x receptors (rxrs), and their dna recognition sequences (tres). this molecular conservation allows examination of potential th disruption in the tractable, in vivo model s ...201728662416
mutation of the inhibitory ethanol site in gabaa ρ1 receptors promotes tolerance to ethanol-induced motor incoordination.genes encoding the ρ1/2 subunits of gabaa receptors have been associated with alcohol (ethanol) dependence in humans, and ρ1 was also shown to regulate some of the behavioral effects of ethanol in animal models. ethanol inhibits gaba-mediated responses in wild-type (wt) ρ1, but not ρ1(t6'y) mutant receptors expressed in xenopus laevis oocytes, indicating the presence of an inhibitory site for ethanol in the second transmembrane helix. in this study, we found that ρ1(t6'y) receptors expressed in ...201728623169
adhfe1: a novel enzyme involved in retinoic acid-dependent hox activation.retinoic acid (ra) signaling is a central pathway regulating anterior-posterior patterning of the embryo through its targets, the hox genes. ra is produced by two sequential oxidations from vitamin a (retinol) and this biosynthesis has to be regulated temporally, spatially and quantitatively. mining xenopus embryonic expression databases identified a novel component of the ra metabolic network, adhfe1. using xenopus laevis embryos as our experimental system we determined the temporal and spatial ...201728621427
cells from subcutaneous tissues contribute to scarless skin regeneration in xenopus laevis froglets.mammals cannot regenerate the dermis and other skin structures after an injury and instead form a scar. however, a xenopus laevis froglet can regenerate scarless skin, including the dermis and secretion glands, on the limbs and trunk after skin excision. subcutaneous tissues in the limbs and trunk consist mostly of muscles. although subcutaneous tissues beneath a skin injury appear disorganized, the cellular contribution of these underlying tissues to skin regeneration remains unclear.201728618059
loops d, e and g in the drosophila dα1 subunit contribute to high neonicotinoid sensitivity of dα1-chicken β2 nicotinic acetylcholine receptor.neonicotinoid insecticides interact with the orthosteric site formed at subunit interfaces of insect nicotinic ach (nach) receptors. however, their interactions with the orthosteric sites at α-non α and α-α subunit interfaces remain poorly understood. the aim of this study was to elucidate the mechanism of neonicotinoid actions using the drosophila dα1-chicken β2 hybrid nach receptor.201728616862
global realized niche divergence in the african clawed frog xenopus laevis.although of crucial importance for invasion biology and impact assessments of climate change, it remains widely unknown how species cope with and adapt to environmental conditions beyond their currently realized climatic niches (i.e., those climatic conditions existing populations are exposed to). the african clawed frog xenopus laevis, native to southern africa, has established numerous invasive populations on multiple continents making it a pertinent model organism to study environmental niche ...201728616199
switch-like behavior enables wnt11 concentration specific response during dorso-ventral axis formation in xenopus laevis.wnt signaling plays a role in diverse processes such as cell proliferation, differentiation, migration or cell polarity. dysfunction of wnt signaling is associated with human diseases and aging. wnts can activate several interacting intracellular signaling pathways, in particular the so called canonical and non-canonical pathways. the canonical wnt response leads to a stabilization of cytoplasmic β-catenin whereas non-canonical wnt signaling can result in the activation of calcium-calmodulin dep ...201728648560
conserved gene regulatory module specifies lateral neural borders across bilaterians.the lateral neural plate border (npb), the neural part of the vertebrate neural border, is composed of central nervous system (cns) progenitors and peripheral nervous system (pns) progenitors. in invertebrates, pns progenitors are also juxtaposed to the lateral boundary of the cns. whether there are conserved molecular mechanisms determining vertebrate and invertebrate lateral neural borders remains unclear. using single-cell-resolution gene-expression profiling and genetic analysis, we present ...201728716930
cip29 is phosphorylated following activation of the dna damage response in xenopus egg extracts.acting through a complex signalling network, dna lesions trigger a range of cellular responses including dna repair, cell cycle arrest, altered gene expression and cell death, which help to limit the mutagenic effects of such dna damage. rna processing factors are increasingly being recognised as important targets of dna damage signalling, with roles in the regulation of gene expression and also more directly in the promotion of dna repair. in this study, we have used a xenopus laevis egg extrac ...201728715428
ensemble and single-molecule analysis of non-homologous end joining in frog egg extracts.non-homologous end joining (nhej) repairs the majority of dna double-strand breaks in human cells, yet the detailed order of events in this process has remained obscure. here, we describe how to employ xenopus laevis egg extract for the study of nhej. the egg extract is easy to prepare in large quantities, and it performs efficient end joining that requires the core end joining proteins ku, dna-pkcs, xlf, xrcc4, and dna ligase iv. these factors, along with the rest of the soluble proteome, are p ...201728645371
xenopus laevis as model system to study dna damage response and replication fork stability.although many players of the dna damage response and dna repair have been identified in several systems their biochemical role is still poorly understood. the use of the xenopus laevis egg extract cell-free system allowed biochemical dissection of dna replication and cell cycle events in a complex biological context. the possibility of manipulating the protein content by using protein depletion procedures makes egg extract a powerful system to study proteins whose inactivation results in cellula ...201728645370
foxd1 protein interacts with wnt and bmp signaling to differentially pattern mesoderm and neural tissue.the foxd1 gene (previously known as brain factor 2/bf2) is expressed during early xenopus laevis development. at gastrula stages, foxd1 is expressed in dorsal mesoderm regions fated for muscle and notochord, while at neurula stages, foxd1 is expressed in the forebrain region. previous studies in the neural plate showed that foxd1 protein acts as transcriptional repressor downstream of bmp antagonism, neuralizing the embryo to control anterior neural cell fates. foxd1 mesoderm function was not ri ...201728621426
roles of the cilium-associated gene ccdc11 in left-right patterning and in laterality disorders in humans.axial determination occurs during early stages of embryogenesis. flaws in laterality patterning result in abnormal positioning of visceral organs, as manifested in heterotaxy syndrome, or complete left-right inversion as in situs inversus totalis. these malformations are often associated with ciliopathies, as seen in primary ciliary dyskinesia. we have recently described a novel mutation in the coiled-coil domain-containing 11 (ccdc11) gene associated with laterality disorders in a consanguineou ...201728621423
adipose tissue macrophages develop from bone marrow-independent progenitors in xenopus laevis and mouse.atms have a metabolic impact in mammals as they contribute to metabolically harmful at inflammation. the control of the atm number may have therapeutic potential; however, information on atm ontogeny is scarce. whereas it is thought that atms develop from circulating monocytes, various tissue-resident mϕs are capable of self-renewal and develop from bm-independent progenitors without a monocyte intermediate. here, we show that amphibian at contains self-renewing atms that populate the at before ...201728642277
using short-term bioassays to evaluate the endocrine disrupting capacity of the pesticides linuron and fenoxycarb.several short-term whole-organism bioassays based on transgenic aquatic models are now under validation by the oecd (organization for economic co-operation and development) to become standardized test guidelines for the evaluation of the endocrine activity of substances. evaluation of the endocrine disrupting capacity of pesticides will be a domain of applicability of these future reference tests. the herbicide linuron and the insecticide fenoxycarb are two chemicals commonly used in agricultura ...201728634053
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