TitleAbstractYear(sorted ascending)
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
expression of the aquaglyceroporin hc-9 in a freeze-tolerant amphibian that accumulates glycerol 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
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
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
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
the xenopus tadpole: an in vivo model to screen drugs favoring multiple sclerosis, development of screening tools for remyelination-promoting molecules is timely.201728752787
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
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
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
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
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
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
isolation and functional characterization of cslsi1, a silicon transporter gene in cucumis sativus.cucumber (cucumis sativus) is a widely grown cucurbitaceous vegetable that exhibits a relatively high capacity for silicon (si) accumulation, but the molecular mechanism for silicon uptake remains to be clarified. here we isolated and characterized cslsi1, a gene encoding a silicon transporter in cucumber (cv. mch-4). cslsi1 shares 55.70 and 90.63% homology with the lsi1s of a monocot and dicot, rice (oryza sativa) and pumpkin (cucurbita moschata), respectively. cslsi1 was predominantly expresse ...201727701737
targeting functional noncoding rnas.noncoding rnas have essential biochemical functions in different areas of cellular metabolism, including protein synthesis, rna splicing, protein secretion, and dna replication. we have successfully used morpholino antisense oligonucleotides for the functional inactivation of small noncoding rnas required for dna replication (y rnas in vertebrates and stem-bulge rnas in nematodes). here we discuss specific issues of targeting functional noncoding rnas for inactivation by morpholino antisense oli ...201728364241
aquaglyceroporins are the entry pathway of boric acid in trypanosoma brucei.the boron element possesses a range of different effects on living beings. it is essential to beneficial at low concentrations, but toxic at excessive concentrations. recently, some boron-based compounds have been identified as promising molecules against trypanosoma brucei, the causative agent of sleeping sickness. however, until now, the boron metabolism and its access route into the parasite remained elusive. the present study addressed the permeability of t. brucei aquaglyceroporins (tbaqps) ...201728087364
functional characterisation and cell specificity of bvsut1, the transporter that loads sucrose into the phloem of sugar beet (beta vulgaris l.) source leaves.sugar beet (beta vulgaris l.) is one of the most important sugar-producing plants worldwide and provides about one third of the sugar consumed by humans. here we report on molecular characterisation of the bvsut1 gene and on the functional characterisation of the encoded transporter. in contrast to the recently identified tonoplast-localised sucrose transporter bvtst2.1 from sugar beet taproots, which evolved within the monosaccharide transporter (mst) superfamily, bvsut1 represents a classical ...201728075052
sucrose transporter localization and function in phloem unloading in developing sucrose transporters (suts) regulate phloem unloading in monocot stems is poorly understood and particularly so for species storing high suc concentrations. to this end, sorghum bicolor suts sbsut1 and sbsut5 were characterized by determining their transport properties heterologously expressed in yeast or xenopus laevis oocytes, and their in planta cellular and subcellular localization. the plasma membrane-localized sbsut1 and sbsut5 exhibited a strong selectivity for suc and high suc affini ...201727986867
the malaria parasite's lactate transporter pffnt is the target of antiplasmodial compounds identified in whole cell phenotypic this study the 'malaria box' chemical library comprising 400 compounds with antiplasmodial activity was screened for compounds that perturb the internal ph of the malaria parasite, plasmodium falciparum. fifteen compounds induced an acidification of the parasite cytosol. two of these did so by inhibiting the parasite's formate nitrite transporter (pffnt), which mediates the h+-coupled efflux from the parasite of lactate generated by glycolysis. both compounds were shown to inhibit lactate tra ...201728178359
hepatitis e virus orf3 is a functional ion channel required for release of infectious particles.hepatitis e virus (hev) is the leading cause of enterically transmitted viral hepatitis globally. of hev's three orfs, the function of orf3 has remained elusive. here, we demonstrate that via homophilic interactions orf3 forms multimeric complexes associated with intracellular endoplasmic reticulum (er)-derived membranes. hev orf3 shares several structural features with class i viroporins, and the function of hev orf3 can be maintained by replacing it with the well-characterized viroporin influe ...201728096411
h(+)-dependent inorganic phosphate uptake in trypanosoma brucei is influenced by myo-inositol transporter.trypanosoma brucei is an extracellular protozoan parasite that causes human african trypanosomiasis or "sleeping sickness". during the different phases of its life cycle, t. brucei depends on exogenous inorganic phosphate (pi), but little is known about the transport of pi in this organism. in the present study, we showed that the transport of (32)pi across the plasma membrane follows michaelis-menten kinetics and is modulated by ph variation, with higher activity at acidic ph. bloodstream forms ...201728185085
two spatially and temporally distinct ca(2+) signals convey arabidopsis thaliana responses to k(+) plants, potassium (k(+) ) homeostasis is tightly regulated and established against a concentration gradient to the environment. despite the identification of ca(2+) -regulated kinases as modulators of k(+) channels, the immediate signaling and adaptation mechanisms of plants to low-k(+) conditions are only partially understood. to assess the occurrence and role of ca(2+) signals in arabidopsis thaliana roots, we employed ratiometric analyses of ca(2+) dynamics in plants expressing the ca(2+) ...201727579668
polar localization of the nip5;1 boric acid channel is maintained by endocytosis and facilitates boron transport in arabidopsis roots.boron uptake in arabidopsis thaliana is mediated by nodulin 26-like intrinsic protein (nip)5;1, a boric acid channel that is located preferentially on the soil side of the plasma membrane in root cells. however, the mechanism underlying this polar localization is poorly understood. here, we show that the polar localization of nip5;1 in epidermal and endodermal root cells is mediated by the phosphorylation of thr residues in the conserved tpg (thrprogly) repeat in the n-terminal region of nip5;1. ...201728341806
models of amphibian myogenesis - the case of bombina variegata.several different models of myogenesis describing early stages of amphibian paraxial myotomal myogenesis are known. myoblasts of xenopus laevis and hymenochirus boettgeri change their position from perpendicular to parallel, in relation to axial organs, and differentiate into mononucleate myotubes. in bombina variegate the myotomal myoblasts change their shape from round to elongate and then differentiate into mononuclear, morphologically mature myotubes. in pelobates fuscus and triturus vulgari ...201728287243
cloning and expression analysis of zygote arrest 1 (zar1) in new zealand white rabbits.zygote arrest 1 (zar1) is an oocyte-specific maternal-effect gene. previous studies indicate that zar1 plays important role in early embryo development, but little is known about its function in rabbit. the objectives of this study were to clone the new zealand white rabbit zar1 gene and to investigate its expression in various organs in groups of animals with different reproductive traits.we obtained a 709-bp zar1 cdna fragment consisting of an 8-bp exon 1, 161-bp exon 2, 75-bp exon 3, 271-bp e ...201728360383
effects of amphibian phylogeny, climate and human impact on the occurrence of the amphibian-killing chytrid fungus.chytridiomycosis, due to the fungus batrachochytrium dendrobatidis (bd), has been associated with the alarming decline and extinction crisis of amphibians worldwide. because conservation programs are implemented locally, it is essential to understand how the complex interactions among host species, climate and human activities contribute to bd occurrence at regional scales. using weighted phylogenetic regressions and model selection, we investigated geographic patterns of bd occurrence along a l ...201728055125
an inducible amphipathic helix within the intrinsically disordered c-terminus is not required for protein biosynthesis, trafficking, or garp2 interaction, but can participate in membrane curvature generation by peripherin-2/rds.peripherin-2/rds is required for biogenesis of vertebrate photoreceptor outer segment organelles. its localization at the high curvature rim domains of outer segment disk membranes suggests that it may act to shape these structures; however, the molecular function of this protein is not yet resolved. here, we apply biochemical, biophysical, and imaging techniques, to elucidate the role(s) played by the protein's intrinsically disordered c-terminal domain, and an incipient amphipathic α-helix con ...201728325841
immune roles of amphibian (xenopus laevis) tadpole granulocytes during frog virus 3 ranavirus infections.infections by frog virus 3 (fv3) and other ranaviruses (rvs) are contributing to the amphibian declines, while the mechanisms controlling anuran tadpole susceptibility and adult frog resistance to rvs, including the roles of polymorphonuclear granulocytes (pmns) during anti-fv3 responses, remain largely unknown. since amphibian kidneys represent an important fv3 target, the inability of amphibian (xenopus laevis) tadpoles to mount effective kidney inflammatory responses to fv3 is thought to cont ...201728238879
amphibian (xenopus laevis) tadpoles and adult frogs mount distinct interferon responses to the frog virus 3 ranavirus.infections of amphibians by frog virus 3 (fv3) and other ranavirus genus members are significantly contributing to the amphibian declines, yet much remains unknown regarding amphibian antiviral immunity. notably, amphibians represent an important step in the evolution of antiviral interferon (ifn) cytokines as they are amongst the first vertebrates to possess both type i and type iii ifns. accordingly, we examined the roles of type i and iii ifns in the skin of fv3-challenged amphibian xenopus l ...201728081430
long term effects of carbaryl exposure on antiviral immune responses in xenopus laevis.water pollutants associated with agriculture may contribute to the increased prevalence of infectious diseases caused by ranaviruses. we have established the amphibian xenopus laevis and the ranavirus frog virus 3 (fv3) as a reliable experimental platform for evaluating the effects of common waterborne pollutants, such as the insecticide carbaryl. following 3 weeks of exposure to 10 ppb carbaryl, x. laevis tadpoles exhibited a marked increase in mortality and accelerated development. exposure at ...201727988452
fmrp regulates neurogenesis in vivo in xenopus laevis tadpoles.fragile x syndrome (fxs) is the leading known monogenic form of autism and the most common form of inherited intellectual disability. fxs results from silencing the fmr1 gene during embryonic development, leading to loss of fragile x mental retardation protein (fmrp), an rna-binding protein that regulates mrna transport, stability, and translation. fxs is commonly thought of as a disease of synaptic dysfunction, however, fmrp expression is lost early in embryonic development, well before most sy ...201725844398
methylmercury exposure during early xenopus laevis development affects cell proliferation and death but not neural progenitor specification.methylmercury (mehg) is a widespread environmental toxin that preferentially and adversely affects developing organisms. to investigate the impact of mehg toxicity on the formation of the vertebrate nervous system at physiologically relevant concentrations, we designed a graded phenotype scale for evaluating xenopus laevis embryos exposed to mehg in solution. embryos displayed a range of abnormalities in response to mehg, particularly in brain development, which is influenced by both mehg concen ...201725496965
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
the phosphoinositide sensitivity of the k(v) channel family.recently, we screened several kv channels for possible dependence on plasma membrane phosphatidylinositol 4,5-bisphosphate (pi(4,5)p 2). the channels were expressed in tsa-201 cells and the pi(4,5)p 2 was depleted by several manipulations in whole-cell experiments with parallel measurements of channel activity. in contrast to reports on excised-patches using xenopus laevis oocytes, we found only kv 7, but none of the other tested kv channels, to be strongly dependent on pi(4,5)p 2. we now have e ...201723907203
williams syndrome transcription factor is critical for neural crest cell function in xenopus laevis.williams syndrome transcription factor (wstf) is one of ∼25 haplodeficient genes in patients with the complex developmental disorder williams syndrome (ws). ws results in visual/spatial processing defects, cognitive impairment, unique behavioral phenotypes, characteristic "elfin" facial features, low muscle tone and heart defects. wstf exists in several chromatin remodeling complexes and has roles in transcription, replication, and repair. chromatin remodeling is essential during embryogenesis, ...201722691402
mustn1 is essential for craniofacial chondrogenesis during xenopus development.mustn1 is a vertebrate-specific protein that, in vitro, was showed to be essential for prechondrocyte function and thus it has the potential to regulate chondrogenesis during embryonic development. we use xenopus laevis as a model to examine mustn1 involvement in chondrogenesis. previous work suggests that mustn1 is necessary but not sufficient for chondrogenic proliferation and differentiation, as well as myogenic differentiation in vitro. mustn1 was quantified and localized in developing xenop ...201722281807
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