Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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| the african clawed frog xenopus laevis: a model organism to study regeneration of the central nervous system. | while an injury to the central nervous system (cns) in humans and mammals is irreversible, amphibians and teleost fish have the capacity to fully regenerate after severe injury to the cns. xenopus laevis has a high potential to regenerate the brain and spinal cord during larval stages (47-54), and loses this capacity during metamorphosis. the optic nerve has the capacity to regenerate throughout the frog's lifespan. here, we review cns regeneration in frogs, with a focus in x. laevis, but also p ... | 2017 | 27693567 |
| genomic organization and modulation of gene expression of the tgf-β and fgf pathways in the allotetraploid frog xenopus laevis. | inductive interactions mediated by the tgf-β and fgf-mapk pathways are essential for specification of the germ layers and embryonic body axes during early vertebrate embryogenesis. tgf-β and fgf ligands signal through receptor ser/thr and tyr kinases, respectively, and these signaling pathways cross-talk to regulate transcription and cell behavior. the allotetraploid xenopus laevis and its ancestral diploid xenopus tropicalis are versatile model organisms with which to study the inductive intera ... | 2017 | 27692744 |
| effects of freezing and activation on membrane quality and dna damage in xenopus tropicalis and xenopus laevis spermatozoa. | there is growing concern over the effect of sperm cryopreservation on dna integrity and the subsequent development of offspring generated from this cryopreserved material. in the present study, membrane integrity and dna stability of xenopus laevis and xenopus tropicalis spermatozoa were evaluated in response to cryopreservation with or without activation, a process that happens upon exposure to water to spermatozoa of some aquatic species. a dye exclusion assay revealed that sperm plasma membra ... | 2017 | 27692061 |
| 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 ... | 2016 | 27688972 |
| xenopus laevis and emerging amphibian pathogens in chile. | amphibians face an extinction crisis with no precedence. two emerging infectious diseases, ranaviral disease caused by viruses within the genus ranavirus and chytridiomycosis due to batrachochytrium dendrobatidis (bd), have been linked with amphibian mass mortalities and population declines in many regions of the globe. the african clawed frog (xenopus laevis) has been indicated as a vector for the spread of these pathogens. since the 1970s, this species has been invasive in central chile. we co ... | 2016 | 27682604 |
| electrophysiological actions of synthetic cathinones on monoamine transporters. | products containing psychoactive synthetic cathinones, such as mephedrone and 3,4-methylenedioxypyrovalerone (mdpv) are prevalent in our society. synthetic cathinones are structurally similar to methamphetamine, and numerous synthetics have biological activity at dopamine, serotonin, and norepinephrine transporters. importantly, monoamine transporters co-transport sodium ions along with their substrate, and movement of substrates and ions through the transporter can generate measurable ionic cur ... | 2017 | 27677783 |
| 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 ... | 2016 | 27677704 |
| 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 ... | 2016 | 27677466 |
| the antidepressant bupropion is a negative allosteric modulator of serotonin type 3a receptors. | the fda-approved antidepressant and smoking cessation drug bupropion is known to inhibit dopamine and norepinephrine reuptake transporters, as well as nicotinic acetylcholine receptors (nachrs) which are cation-conducting members of the cys-loop superfamily of ion channels, and more broadly pentameric ligand-gated ion channels (plgics). in the present study, we examined the ability of bupropion and its primary metabolite hydroxybupropion to block the function of cation-selective serotonin type 3 ... | 2017 | 27671323 |
| 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 ... | 2016 | 27670931 |
| 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 ... | 2016 | 27669663 |
| tissue-specific selenium accumulation and toxicity in adult female xenopus laevis chronically exposed to elevated dietary selenomethionine. | selenium (se) is a developmental toxicant that is also capable of altering the bioenergetic and endocrine status of adult fish. to date, aquatic ecotoxicological research has predominantly focused on the toxic effects of se in fish, and minimal information has been published related to amphibians. the objective of the present study was to investigate the potential toxicity associated with chronically elevated dietary se consumption in adult female amphibians utilizing the model species xenopus l ... | 2017 | 27666932 |
| research advances on animal genetics in china in 2015. | chinese scientists have made significant achievements in the field of animal genetics in 2015. incomplete statistics show that among all the publications of 2015 involving nematode (caenorhabditis elegans), fly (drosophila melanogaster), zebrafish (danio rerio), african clawed frog (xenopus) or mice (mus musculus), about 1/5 publications are from china. many innovative studies were published in high-impact international academic journals by chinese scientists, including the identification of a p ... | 2016 | 27655312 |
| 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. | 2016 | 27653971 |
| comparative study of diclofenac-induced embryotoxicity and teratogenesis in xenopus laevis and lithobates catesbeianus, using the frog embryo teratogenesis assay: xenopus (fetax). | water is an increasingly deteriorated, limited natural resource due to population increase and industrialization. also, the widespread use of pharmaceuticals in modern society leads to their presence in domestic, hospital and industrial effluents. due to their analgesic properties, some of the most commonly used pharmaceuticals are nonsteroidal anti-inflammatory drugs (nsaids). high concentrations of one these products, diclofenac (dcf), have been detected in effluents and water bodies of differ ... | 2017 | 27644024 |
| 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 ... | 2016 | 27640133 |
| an implantable eng detector with in-system velocity selective recording (vsr) capability. | detection and classification of electroneurogram (eng) signals in the peripheral nervous system can be achieved by velocity selective recording (vsr) using multi-electrode arrays. this paper describes an implantable vsr-based eng recording system representing a significant development in the field since it is the first system of its type that can record naturally evoked eng and be interfaced wirelessly using a low data rate transcutaneous link. the system consists of two cmos asics one of which ... | 2017 | 27638107 |
| tril targets smad7 for degradation to allow hematopoietic specification in xenopus embryos. | in xenopus laevis, bone morphogenetic proteins (bmps) induce expression of the transcription factor gata2 during gastrulation, and gata2 is required in both ectodermal and mesodermal cells to enable mesoderm to commit to a hematopoietic fate. here, we identify tril as a gata2 target gene that is required in both ectoderm and mesoderm for primitive hematopoiesis to occur. tril is a transmembrane protein that functions as a co-receptor for toll-like receptors to mediate innate immune responses in ... | 2016 | 27633996 |
| non-selective cation channel activity of aquaporin atpip2;1 regulated by ca(2+) and ph. | the aquaporin atpip2;1 is an abundant plasma membrane intrinsic protein in arabidopsis thaliana that is implicated in stomatal closure, and is highly expressed in plasma membranes of root epidermal cells. when expressed in xenopus laevis oocytes, atpip2;1 increased water permeability and induced a non-selective cation conductance mainly associated with na(+) . a mutation in the water pore, g103w, prevented both the ionic conductance and water permeability of pip2;1. co-expression of atpip2;1 wit ... | 2016 | 27620834 |
| 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 ... | 2016 | 27620076 |
| n6-methyladenosine sequencing highlights the involvement of mrna methylation in oocyte meiotic maturation and embryo development by regulating translation in xenopus laevis. | during the oogenesis of xenopus laevis, oocytes accumulate maternal materials for early embryo development. as the transcription activity of the oocyte is silenced at the fully grown stage and the global genome is reactivated only by the mid-blastula embryo stage, the translation of maternal mrnas accumulated during oocyte growth should be accurately regulated. previous evidence has illustrated that the poly(a) tail length and rna binding elements mediate rna translation regulation in the oocyte ... | 2016 | 27613873 |
| 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 ... | 2016 | 27611864 |
| 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 ... | 2016 | 27605520 |
| 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 ... | 2016 | 27590156 |
| 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 ... | 2016 | 27585825 |
| 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 ... | 2016 | 27584618 |
| 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 ... | 2016 | 27582097 |
| 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 ... | 2016 | 27581452 |
| 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 ... | 2016 | 27581201 |
| two spatially and temporally distinct ca(2+) signals convey arabidopsis thaliana responses to k(+) deficiency. | in plants, potassium (k(+) ) homeostasis is tightly regulated and established against a concentration gradient to the environment. despite the identification of ca(2+) -regulated kinases as modulators of k(+) channels, the immediate signaling and adaptation mechanisms of plants to low-k(+) conditions are only partially understood. to assess the occurrence and role of ca(2+) signals in arabidopsis thaliana roots, we employed ratiometric analyses of ca(2+) dynamics in plants expressing the ca(2+) ... | 2017 | 27579668 |
| 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 ... | 2016 | 27578778 |
| 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 ... | 2016 | 27576864 |
| 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 ... | 2016 | 27569373 |
| the sox transcriptional factors: functions during intestinal development in vertebrates. | the intestine has long been studied as a model for adult stem cells due to the life-long self-renewal of the intestinal epithelium through the proliferation of the adult intestinal stem cells. recent evidence suggests that the formation of adult intestinal stem cells in mammals takes place during the thyroid hormone-dependent neonatal period, also known as postembryonic development, which resembles intestinal remodeling during frog metamorphosis. studies on the metamorphosis in xenopus laevis ha ... | 2017 | 27567710 |
| 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 ... | 2016 | 27559128 |
| functional assessment of slc4a11, an integral membrane protein mutated in corneal dystrophies. | slc4a11, a member of the slc4 family of bicarbonate transporters, is a widely expressed integral membrane protein, abundant in kidney and cornea. mutations of slc4a11 cause some cases of the blinding corneal dystrophies, congenital hereditary endothelial dystrophy, and fuchs endothelial corneal dystrophy. these diseases are marked by fluid accumulation in the corneal stroma, secondary to defective fluid reabsorption by the corneal endothelium. the role of slc4a11 in these corneal dystrophies is ... | 2016 | 27558157 |
| 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 ... | 2016 | 27557040 |
| 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 ... | 2016 | 27555600 |
| 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 ... | 2016 | 27554288 |
| 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 ... | 2016 | 27554108 |
| 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 ... | 2016 | 27550844 |
| robust identification of ptbp1-dependent splicing events by a junction-centric approach in xenopus laevis. | regulation of alternative splicing is an important process for cell differentiation and development. down-regulation of ptbp1, a regulatory rna-binding protein, leads to developmental skin defects in xenopus laevis. to identify ptbp1-dependent splicing events potentially related to the phenotype, we conducted rnaseq experiments following ptbp1 depletion. we systematically compared exon-centric and junction-centric approaches to detect differential splicing events. we showed that the junction-cen ... | 2017 | 27546377 |
| 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 ... | 2016 | 27543892 |
| characterisation and vascular expression of nitric oxide synthase 3 in amphibians. | in mammals, nitric oxide (no) produced by nitric oxide synthase 3 (nos3) localised in vascular endothelial cells is an important vasodilator but the presence of nos3 in the endothelium of amphibians has been concluded to be absent, based on physiological studies. in this study, a nos3 cdna was sequenced from the toad, rhinella marina. the open reading frame of r. marina nos3 encoded an 1170 amino acid protein that showed 81 % sequence identity to the recently cloned xenopus tropicalis nos3. rhin ... | 2016 | 27543051 |
| gene expression analysis of developing cell groups in the pretectal region of xenopus laevis. | our previous analysis of progenitor domains in the pretectum of xenopus revealed three molecularly distinct anteroposterior subdivisions, identified as precommissural (pcp), juxtacommissural (jcp), and commissural (cop) histogenetic domains (morona et al. [2011] j comp neurol 519:1024-1050). here we analyzed at later developmental stages the nuclei derived from these areas, attending to their gene expression patterns and histogenesis. transcription-factor gene markers were used to selectively ma ... | 2017 | 27539385 |
| 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. | 2016 | 27537208 |
| 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 ... | 2016 | 27529348 |
| 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 ... | 2016 | 27528041 |
| identification and comparative analyses of siamois cluster genes in xenopus laevis and tropicalis. | two siamois-related homeobox genes siamois (sia1) and twin (sia2), have been reported in xenopus laevis. these genes are expressed in the blastula chordin- and noggin-expressing (bcne) center and the nieuwkoop center, and have complete secondary axis-inducing activity when over-expressed on the ventral side of the embryo. using whole genome sequences of x. tropicalis and x. laevis, we identified two additional siamois-related genes, which are tandemly duplicated near sia1 and sia2 to form the si ... | 2017 | 27522305 |
| 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. | 2016 | 27521439 |
| synthesis of deuterium labeled cholesterol and steroids and their use for metabolic studies. | a simple method is described for the preparation of [6,7,7(-2)h3] sterols and steroids. the synthesis starts with a δ(5)-sterol or steroid and involves preparation of the 6-oxo-3α,5α-cyclosteroid, base exchange in the presence of deuterium oxide to introduce two deuteriums at the c-7 position and sodium borodeuteride reduction of the 6-oxo group to introduce the third deuterium atom at c-6. rearrangement of the [6,7,7(-2)h3]6α-hydroxy-3α,5α-cyclosteroid then gives the desired [6,7,7(-2)h3]-δ(5) ... | 1982 | 27519440 |
| 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 ... | 2016 | 27512151 |
| 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 ... | 2016 | 27503008 |
| 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 ... | 2016 | 27502018 |
| 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 ... | 2016 | 27499877 |
| distinct patterns of endosulfatase gene expression during xenopus laevis limb development and regeneration. | the heparan sulfate 6-o-endosulfatases sulf1 and sulf2 regulate multiple cellular processes and organ development. sulfs modulate a range of heparan-sulfate-dependent extracellular pathways, including the fibroblast growth factor, bone morphogenetic protein, and wingless/wnt signaling pathways. known patterns of sulf transcript expression together with functional experiments have implicated the sulfs in chondrogenesis and muscle regeneration in mammals. here, we describe the expression patterns ... | 2015 | 27499864 |
| ectopic blastema induction by nerve deviation and skin wounding: a new regeneration model in xenopus laevis. | recently, the accessory limb model (alm) has become an alternative study system for limb regeneration studies in axolotls instead of using an amputated limb. alm progresses limb regeneration study in axolotls because of its advantages. to apply and/or to compare knowledge in axolotl alm studies to other vertebrates is a conceivable next step. first, xenopus laevis, an anuran amphibian, was investigated. a xenopus frog has hypomorphic regeneration ability. its regeneration ability has been consid ... | 2014 | 27499859 |
| 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 ... | 2016 | 27497601 |
| 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 ... | 2016 | 27489339 |
| 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 ... | 2016 | 27488374 |
| development of a new decision tree to rapidly screen chemical estrogenic activities of xenopus laevis. | during the last past decades, there is an increasing number of studies about estrogenic activities of the environmental pollutants on amphibians and many determination methods have been proposed. however, these determination methods are time-consuming and expensive, and a rapid and simple method to screen and test the chemicals for estrogenic activities to amphibians is therefore imperative. herein is proposed a new decision tree formulated not only with physicochemical parameters but also a bio ... | 2014 | 27485568 |
| 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, ... | 2016 | 27485339 |
| 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 ... | 2016 | 27485009 |
| extensions to in silico bioactivity predictions using pathway annotations and differential pharmacology analysis: application to xenopus laevis phenotypic readouts. | the simultaneous increase of computational power and the availability of chemical and biological data have contributed to the recent popularity of in silico bioactivity prediction algorithms. such methods are commonly used to infer the 'mechanism of action' of small molecules and they can also be employed in cases where full bioactivity profiles have not been established experimentally. however, protein target predictions by themselves do not necessarily capture information about the effect of a ... | 2013 | 27481146 |
| 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 ... | 2016 | 27480688 |
| translational profiling of retinal ganglion cell optic nerve regeneration in xenopus laevis. | unlike adult mammals, adult frogs regrow their optic nerve following a crush injury, making xenopus laevis a compelling model for studying the molecular mechanisms that underlie neuronal regeneration. using translational ribosome affinity purification (trap), a method to isolate ribosome-associated mrnas from a target cell population, we have generated a transcriptional profile by rna-seq for retinal ganglion cells (rgc) during the period of recovery following an optic nerve injury. based on bio ... | 2017 | 27471010 |
| boric acid is reproductively toxic to adult xenopus laevis, but not endocrine active. | the potential reproductive and endocrine toxicity of boric acid (ba) in the african clawed frog, xenopus laevis, was evaluated using a 30-day exposure of adult frogs. adult female and male frogs established as breeders were exposed to a culture water control and 4 target (nominal) test concentrations [5.0, 7.5, 10.0, and 15 mg boron (b)/l, equivalent to 28.5, 42.8, 57.0, and 85.5 mg ba/l] using flow-through diluter exposure system. the primary endpoints measured were adult survival, growth (weig ... | 2016 | 27466210 |
| a functional comparison of cardiac troponin c from representatives of three vertebrate taxa: linking phylogeny and protein function. | the ca2+ affinity of cardiac troponin c (ctnc) from rainbow trout is significantly greater than that of ctnc from mammalian species. this high affinity is thought to enable cardiac function in trout at low physiological temperatures and is due to residues asn2, ile28, gln29, and asp30 (gillis et al., 2005, physiol genomics, 22, 1-7). interestingly, the ctnc of the african clawed frog xenopus laevis (frog ctnc) contains gln29 and asp30 but the residues at positions 2 and 28 are those found in all ... | 2016 | 27453566 |
| infrared spectroscopy detects changes in an amphibian cell line induced by fungicides: comparison of single and mixture effects. | amphibians are regarded as sensitive sentinels of environmental pollution due to their permeable skin and complex life cycle, which usually involves reproduction and development in the aquatic environment. fungicides are widely applied agrochemicals and have been associated with developmental defects in amphibians; thus, it is important to determine chronic effects of environmentally-relevant concentrations of such contaminants in target cells. infrared (ir) spectroscopy has been employed to sig ... | 2016 | 27450236 |
| carbon monoxide modulates connexin function through a lipid peroxidation-dependent process: a hypothesis. | hemichannels are ion channels composed of six connexins (cxs), and they have the peculiarity to be permeable not only to ions, but also to molecules such as atp and glutamate. under physiological conditions they present a low open probability, which is sufficient to enable them to participate in several physiological functions. however, massive and/or prolonged hemichannel opening induces or accelerates cell death. therefore, the study of the molecular mechanisms that control hemichannel activit ... | 2016 | 27445849 |
| impaired gonadal and somatic development corroborate vulnerability differences to the synthetic estrogen ethinylestradiol among deeply diverged anuran lineages. | amphibians are undergoing a global decline. one poorly investigated reason could be the pollution of aquatic habitats by endocrine disrupting compounds (edcs). we tested the susceptibility to the synthetically stabilized estrogen 17α-ethinylestradiol (ee2) in three deeply diverged anuran species, differing in sex determination systems, types of gonadogenesis and larval ecologies. to understand whether data from the amphibian model xenopus laevis (pipidae) are analogous and applicable to only dis ... | 2016 | 27434076 |
| teratogenic effects of five anticancer drugs on xenopus laevis embryos. | in recent years, the environmental presence of pharmaceuticals - including anticancer drugs - is an emerging issue. because of the lack of appropriate critical studies about anticancer drug effects in frogs, the aim of the present study was to investigate lethal and teratogenic effects of five anticancer drugs widely used in large quantities, i.e. 5-flourouracil, capecitabine, cisplatin, etoposide, and imatinib, in the embryos of the south african clawed frog, xenopus laevis, using fetax - frog ... | 2016 | 27423131 |
| effects of elevated in ovo selenium exposure on late stage development of xenopus laevis tadpoles. | the effects of elevated in ovo selenium (se) exposure on late stage larval xenopus laevis development were investigated. adult females were fed diets augmented with selenomethionine for 68 days and bred with untreated males to obtain embryos with measured concentrations of 1.6 (control), 10.8, 28.1 and 81.7 μg se/g dry mass. embryos were reared under uncontaminated conditions until 50 % of individuals within an aquarium had completed metamorphosis. the highest in ovo se exposure group exhibited ... | 2016 | 27412338 |
| genes coding for cyclin-dependent kinase inhibitors are fragile in xenopus. | cell proliferation is strictly regulated by the dosage balance among cell-cycle regulators such as cdk/cyclin complexes and cdk-inhibitors. even in the allotetraploid genome of xenopus laevis, the dosage balance must be maintained for animals to stay alive, and the duplicated homeologous genes seem to have gradually changed, through evolution, resulting in the best genes for them to thrive. in the xenopus laevis genome, while homeologous gene pairs of cdks are fundamentally maintained and a few ... | 2017 | 27393661 |
| three-step test system for the identification of novel gabaa receptor modulating food plants. | potentiation of γ-amino butyric acid (gaba)-induced gabaa receptor (gabaar) activation is a common pathway to achieve sedative, sleep-enhancing, anxiolytic, and antidepressant effects. presently, a three-component test system was established for the identification of novel gabaar modulating food plants. in the first step, potentiation of gaba-induced response of the gabaar was analysed by two-electrode voltage clamp (tevc) for activity on human α1β2-gabaar expressed in xenopus laevis oocytes. po ... | 2016 | 27392961 |
| xenopus laevis nkx5.3 and sensory organ homeobox (soho) are expressed in developing sensory organs and ganglia of the head and anterior trunk. | nkx5 family members are homeobox transcription factors important for sensory organ development. several members of the nkx5 family are expressed in the eye, brain, developing ear, and lateral line. members of this family have been previously identified in medaka, chick, and mouse. here, we characterize two members of the nkx5 family, nkx5.3 and soho, in xenopus laevis. we verify the identity of x. laevis nkx5.3 and soho by phylogenetic comparison to chicken, medaka, and zebrafish orthologs. both ... | 2016 | 27392729 |
| platelet derived growth factor b gene expression in the xenopus laevis developing central nervous system. | platelet-derived growth factor b (pdgf-b) belongs to the mitogen and growth factor family and like the other members it has many roles in cell differentiation, proliferation and migration during development, adult life and in pathological conditions. among them it has been observed that aberrant pdgf signalling is frequently linked to glioma development and progression, and pdgf-b over-expression in mouse neural progenitors leads to the formation of gliomas. despite this evidence, the mechanisms ... | 2016 | 27389987 |
| noggin 1 overexpression in retinal progenitors affects bipolar cell generation. | waves of bone morphogenetic proteins (bmps) and their antagonists are present during initial eye development, but their possible roles in retinogenesis are still unknown. we have recently shown that noggin 1, a bmp antagonist, renders pluripotent cells able to differentiate into retinal precursors, and might be involved in the maintenance of retinal structures in the adult vertebrate eye. here, we report that noggin 1, differently from noggin 2 and noggin 4, is expressed during all phases of xen ... | 2016 | 27389985 |
| comparative expression study of sipa family members during early xenopus laevis development. | the signal-induced proliferation-associated (sipa) protein family belongs to the rapgap protein superfamily. previous studies mainly focused on the expression and function of sipa genes in vertebrate neuronal tissue. only limited data about the embryonic expression pattern of the genes are currently available. our study provides the first expression analysis of sipa1, sipa1l1, sipa1l2, and sipa1l3 during early development of the vertebrate organism xenopus laevis. in silico, analysis revealed th ... | 2016 | 27384056 |
| analysis of cell size in the gastrula of ten frog species reveals a correlation of egg with cell sizes, and a conserved pattern of small cells in the marginal zone. | we investigated the relationship between egg and cell sizes in the early gastrula of ten species of frogs with eggs of 1,100-3,500 μm diameters. we asked whether differences in cell size of the vegetal region, blastocoel roof, and marginal zone of the early gastrula were associated with egg size. alternatively, we proposed that cell size differences may associate with gastrulation characteristics. the analyzed species were as follows: xenopus laevis, engystomops randi, engystomops coloradorum, e ... | 2017 | 27381278 |
| in-cell protein structures from 2d nmr experiments. | in-cell nmr spectroscopy provides atomic resolution insights into the structural properties of proteins in cells, but it is rarely used to solve entire protein structures de novo. here, we introduce a paramagnetic lanthanide-tag to simultaneously measure protein pseudocontact shifts (pcss) and residual dipolar couplings (rdcs) to be used as input for structure calculation routines within the rosetta program. we employ this approach to determine the structure of the protein g b1 domain (gb1) in i ... | 2016 | 27379949 |
| inter- and intra-subunit butanol/isoflurane sites of action in the human glycine receptor. | glycine receptors (glyrs) mediate inhibitory neurotransmission and are targets for alcohols and anesthetics in brain. glyr transmembrane (tm) domains contain critical residues for alcohol/anesthetic action: amino acid a288 in tm3 forms crosslinks with tm1 (i229) in the adjacent subunit as well as tm2 (s267) and tm4 (y406, w407, i409, y410) in the same subunit. we hypothesized that these residues may participate in intra-subunit and inter-subunit sites of alcohol/anesthetic action. the following ... | 2016 | 27378846 |
| loss of function of napiiia causes nephrocalcinosis and possibly kidney insufficiency. | inherited metabolic disorders associated with nephrocalcinosis are rare conditions. the aim of this study was to identify the genetic cause of an israeli-arab boy from a consanguineous family with severe nephrocalcinosis and kidney insufficiency. | 2016 | 27378183 |
| the enigma of the dichotomic pressure response of glun1-4a/b splice variants of nmda receptor: experimental and statistical analyses. | professional deep-water divers, exposed to hyperbaric pressure (hp) above 1.1 mpa, develop high pressure neurological syndrome (hpns), which is associated with central nervous system (cns) hyperexcitability. it was previously reported that hp augments n-methyl-d-aspartate receptor (nmdar) synaptic response, increases neuronal excitability and potentially causes irreversible neuronal damage. our laboratory has reported differential current responses under hp conditions in nmdar subtypes that cont ... | 2016 | 27375428 |
| evolution of innate-like t cells and their selection by mhc class i-like molecules. | until recently, major histocompatibility complex (mhc) class i-like-restricted innate-like αβt (it) cells expressing an invariant or semi-invariant t cell receptor (tcr) repertoire were thought to be a recent evolutionary acquisition restricted to mammals. however, molecular and functional studies in xenopus laevis have demonstrated that it cells, defined as mhc class i-like-restricted innate-like αβt cells with a semi-invariant tcr, are evolutionarily conserved and prominent from early developm ... | 2016 | 27368412 |
| expression and localization of the xenopus laevis small heat shock protein, hspb6 (hsp20), in a6 kidney epithelial cells. | small heat shock proteins (shsps) are molecular chaperones that bind to unfolded protein, inhibit the formation of toxic aggregates and facilitate their refolding and/or degradation. previously, the only shsps that have been studied in detail in the model frog system, xenopus laevis, were members of the hsp30 family and hspb1 (hsp27). we now report the analysis of x. laevis hspb6, an ortholog of mammalian hspb6. x. laevis hspb6 cdna encodes a 168 aa protein that contains an α-crystallin domain, ... | 2016 | 27354198 |
| phosphocholine - an agonist of metabotropic but not of ionotropic functions of α9-containing nicotinic acetylcholine receptors. | we demonstrated previously that phosphocholine and phosphocholine-modified macromolecules efficiently inhibit atp-dependent release of interleukin-1β from human and murine monocytes by a mechanism involving nicotinic acetylcholine receptors (nachr). interleukin-1β is a potent pro-inflammatory cytokine of innate immunity that plays pivotal roles in host defence. control of interleukin-1β release is vital as excessively high systemic levels cause life threatening inflammatory diseases. in spite of ... | 2016 | 27349288 |
| maintenance of the epithelial barrier and remodeling of cell-cell junctions during cytokinesis. | epithelial integrity and barrier function must be maintained during the complex cell shape changes that occur during cytokinesis in vertebrate epithelial tissue. here, we investigate how adherens junctions and bicellular and tricellular tight junctions are maintained and remodeled during cell division in the xenopus laevis embryo. we find that epithelial barrier function is not disrupted during cytokinesis and is mediated by sustained tight junctions. using fluorescence recovery after photobleac ... | 2016 | 27345163 |
| increased apoptosis and abnormal visual behavior by histone modifications with exposure to para-xylene in developing xenopus. | xylene and its derivatives are raw materials widely used in industry and known to be toxic to animals. however, the mechanism underlying the neurotoxicity of para-xylene (px) to the central nervous system (cns) in vivo is less clear. here, we exposed xenopus laevis tadpoles to sub-lethal concentrations of px during the critical period of brain development to determine the effects of px on xenopus development and visual behavior. we found that the abnormality rate was significantly increased with ... | 2016 | 27343828 |
| interaction of atorvastatin with the human glial transporter slc16a1. | solute carrier (slc) 16a1 is a ph-dependent carrier of 5-oxoproline, a derivative of the amino acid. slc16a1 interacts with carboxylate group-containing substrates, which are also present in atorvastatin, and might be the reason for its ability to interact with atorvastatin. does atorvastatin interact with the carrier? does it also interact with the carrier via the substrate recognition site? this study was carried out to answer these questions. polymerase chain reaction was used to determine th ... | 2016 | 27341998 |
| slah1, a homologue of the slow type anion channel slac1, modulates shoot cl- accumulation and salt tolerance in arabidopsis thaliana. | salinity tolerance is correlated with shoot chloride (cl(-)) exclusion in multiple crops, but the molecular mechanisms of long-distance cl(-) transport are poorly defined. here, we characterize the in planta role of atslah1 (a homologue of the slow type anion channel-associated 1 (slac1)). this protein, localized to the plasma membrane of root stelar cells, has its expression reduced by salt or aba, which are key predictions for a protein involved with loading cl(-) into the root xylem. artifici ... | 2016 | 27340232 |
| overexpression of leap2 impairs xenopus embryonic development and modulates fgf and activin signals. | besides its widely described function in the innate immune response, no other clear physiological function has been attributed so far to the liver-expressed-antimicrobial-peptide 2 (leap2). we used the xenopus embryo model to investigate potentially new functions for this peptide. we identified the amphibian leap2 gene which is highly related to its mammalian orthologues at both structural and sequence levels. the gene is expressed in the embryo mostly in the endoderm-derived tissues. accordingl ... | 2016 | 27335344 |
| wide and high resolution tension measurement using fret in embryo. | during embryonic development, physical force plays an important role in morphogenesis and differentiation. stretch sensitive fluorescence resonance energy transfer (fret) has the potential to provide non-invasive tension measurements inside living tissue. in this study, we introduced a fret-based actinin tension sensor into xenopus laevis embryos and demonstrated that this sensor captures variation of tension across differentiating ectoderm. the actinin tension sensor, containing mcherry and egf ... | 2016 | 27335157 |
| metabolic cost of osmoregulation in a hypertonic environment in the invasive african clawed frog xenopus laevis. | studies of aquatic invertebrates reveal that salinity affects feeding and growth rates, reproduction, survival, and diversity. little is known, however, about how salinity impacts the energy budget of vertebrates and amphibians in particular. the few studies focused on this topic in vertebrates suggest that the ingestion of salts and the resulting osmoregulatory activity is energetically expensive. we analyzed the effect of saline acclimation on standard metabolic rates (smr) and the activities ... | 2016 | 27334694 |
| alanine to valine substitutions in the pore helix iiip1 and linker-helix iiil45 confer cockroach sodium channel resistance to ddt and pyrethroids. | pyrethroid insecticides exert toxic effects by prolonging the opening of voltage-gated sodium channels. more than 20 sodium channel mutations from arthropod pests and disease vectors have been confirmed to confer pyrethroid resistance. these mutations have been valuable in elucidating the molecular interaction between pyrethroids and sodium channels, including identification of two pyrethroid receptor sites. previously, two alanine to valine substitutions, one in the pore helix iiip1 and the oth ... | 2016 | 27328896 |
| sumoylation of dna topoisomerase iiα regulates histone h3 kinase haspin and h3 phosphorylation in mitosis. | dna topoisomerase ii (top2) plays a pivotal role in faithful chromosome separation through its strand-passaging activity that resolves tangled genomic dna during mitosis. additionally, top2 controls progression of mitosis by activating cell cycle checkpoints. recent work showed that the enzymatically inert c-terminal domain (ctd) of top2 and its posttranslational modification are critical to this checkpoint regulation. however, the molecular mechanism has not yet been determined. by using xenopu ... | 2016 | 27325792 |
| molecular mode of action of cgs 9895 at α1 β2 γ2 gabaa receptors. | γ-aminobutyric type a (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. previously, pyrazoloquinoline 2-p-methoxyphenylpyrazolo [4,3-c] quinolin-3(5h)-one (cgs 9895) was described as a positive allosteric modulator acting through the α+/β- interface in the extracellular domain of gabaa receptors. the localization of the binding site was based on a steric ... | 2016 | 27319298 |
| exploring the functions of nonclassical mhc class ib genes in xenopus laevis by the crispr/cas9 system. | a large family of highly related and clustered xenopus nonclassical mhc class ib (xnc) genes influences xenopus laevis immunity and potentially other physiological functions. using rna interference (rnai) technology, we previously demonstrated that one of xnc genes, xnc10.1, is critical for the development and function of a specialized innate t (it) cell population. however, rnai limitation such as a variable and unstable degree of gene silencing in f0 and f1 generations is hampering a thorough ... | 2017 | 27318386 |
| ddt exposure of frogs: a case study from limpopo province, south africa. | amphibians are globally under pressure with environmental contaminants contributing to this. despite caution aired more than 80 years ago of threats posed to amphibians by ddt spraying for disease vector control, no data have been published on concentrations or effects of ddt contamination in frogs from areas where ddt is actively sprayed to control the insect vectors of malaria. in this study, we sampled fat bodies of xenopus laevis and xenopus muelleri naturally occurring in an area where indo ... | 2016 | 27317939 |
| label-free quantification of proteins in single embryonic cells with neural fate in the cleavage-stage frog (xenopus laevis) embryo using capillary electrophoresis electrospray ionization high-resolution mass spectrometry (ce-esi-hrms). | quantification of protein expression in single cells promises to advance a systems-level understanding of normal development. using a bottom-up proteomic workflow and multiplexing quantification by tandem mass tags, we recently demonstrated relative quantification between single embryonic cells (blastomeres) in the frog (xenopus laevis) embryo. in this study, we minimize derivatization steps to enhance analytical sensitivity and use label-free quantification (lfq) for single xenopus cells. the t ... | 2016 | 27317400 |