| evidence for a change in expression of dna ligase genes in the pleurodeles waltlii germ line during gonadogenesis. | the expression of dna ligase genes was studied using the nuclear transplantation approach in the germ line of pleurodeles waltlii (p. waltlii) just before and during gonadogenesis. germ cell (gc) nuclei were isolated from larvae of p. waltlii and transplanted into unfertilized ambystoma mexicanum eggs. dna ligase activity in these eggs was then analyzed after sucrose gradient fractionation. the activity of dna ligase i (heavy form, 7.5 s) of p. waltlii was present when the transplanted gc nuclei ... | 2009 | 2776966 |
| promotion of chromatophore differentiation in isolated premigratory neural crest cells by extracellular matrix material explanted on microcarriers. | this study was undertaken to determine whether premigratory neural crest cells of the axolotl embryo differentiate autonomously into chromatophores, or whether stimuli from the environment, particularly from the extracellular matrix, are required for this process. neural crest cells were excised from the dorsal part of the premigratory crest cord and cultured alone, either in a serum-free salt solution or in the presence of fetal calf serum (fcs), and together with explants of the neural tube or ... | 2010 | 3081390 |
| the pattern of innervation in serially duplicated axolotl limbs: further evidence for the existence of local pathway cues? | the innervation of the biceps muscle was examined in regenerated and vitamin a-induced serially duplicated axolotl forelimbs using retrograde transport of horseradish peroxidase. the regenerated biceps muscle becomes innervated by motor neurones in the same position in the spinal cord as the normal biceps motor pool. in previous experiments in which the innervation of a second copy of a proximal limb muscle was examined in serially duplicated limbs (stephens, holder & maden, 1985), the duplicate ... | 2012 | 3652982 |
| cellular retinoic acid binding protein: detection and quantitation in regenerating axolotl limbs. | the concentrations of apo (unoccupied), holo (occupied), and total cellular retinoic acid binding protein (crabp) were measured at various stages of axolotl limb regeneration. the ratio of apo-crabp to holo-crabp declined with advancing regenerate stage until the crabp was all in the holo form. the increase in holo-crabp is correlated with a stage-dependent shift in the effect of exogenous retinoic acid on regenerate pattern, from pattern duplication to inhibition of regeneration. the data sugge ... | 2010 | 2838564 |
| comparison of the effects of vitamin a on limb development and regeneration in the axolotl, ambystoma mexicanum. | the objective of this investigation was to compare the effect of vitamin a on limb development and limb regeneration in the same animal, at the same time, thus eliminating the possibility that species differences or different rates of uptake between animals would influence the results. axolotl larvae had both right limbs amputated and then were treated with retinol palmitate by immersion at 60 or 300 mg l-1 for 4 or 10 days. intact left developing limbs at the cone, two-digit, or four-digit stag ... | 2013 | 3711785 |
| regeneration from half lower arms in the axolotl. | a technique involving grafting of pieces of skin from the head onto the limb in order to isolate halves of the limb is described. this technique was used to isolate posterior, anterior, dorsal and ventral halves of the lower arm. all halves produced regenerates but no part of the limb was able to produce a high proportion of regenerates with a complete pattern of skeletal structures. posterior half stumps regenerated limbs with a mean digit number of 2.7 and had a normal dorsoventral muscle patt ... | 2012 | 3540176 |
| an ambystoma mexicanum est sequencing project: analysis of 17,352 expressed sequence tags from embryonic and regenerating blastema cdna libraries. | the ambystomatid salamander, ambystoma mexicanum (axolotl), is an important model organism in evolutionary and regeneration research but relatively little sequence information has so far been available. this is a major limitation for molecular studies on caudate development, regeneration and evolution. to address this lack of sequence information we have generated an expressed sequence tag (est) database for a. mexicanum. | 2004 | 15345051 |
| amelogenin evolution and tetrapod enamel structure. | amelogenins are the major proteins involved in tooth enamel formation. in the present study, we have cloned and sequenced four novel amelogenins from three amphibian species in order to analyze similarities and differences between mammalian and non-mammalian amelogenins. the newly sequenced amphibian amelogenin sequences were from a red-eyed tree frog (litoria chloris) and a mexican axolotl (ambystoma mexicanum). we identified two amelogenin isoforms in the eastern red-backed salamander (plethod ... | 2009 | 19828974 |
| de novo transcriptome sequencing of axolotl blastema for identification of differentially expressed genes during limb regeneration. | salamanders are unique among vertebrates in their ability to completely regenerate amputated limbs through the mediation of blastema cells located at the stump ends. this regeneration is nerve-dependent because blastema formation and regeneration does not occur after limb denervation. to obtain the genomic information of blastema tissues, de novo transcriptomes from both blastema tissues and denervated stump ends of ambystoma mexicanum (axolotls) 14 days post-amputation were sequenced and compar ... | 2013 | 23815514 |
| presence and prevalence of batrachochytrium dendrobatidis in commercial amphibians in mexico city. | in mexico city, native and exotic amphibians are commonly sold through the pet trade. this study investigates the presence of batrachochytrium dendrobatidis (bd) in native amphibians being sold at two commercial markets and at a herpetarium in mexico city. a total of 238 individuals (6 genera and 12 species) were tested for bd using real-time polymerase chain reaction (pcr) analysis. there were 197 bd-positive individuals (prevalence 82%) from five species of amphibians. hyla eximia from the mar ... | 2014 | 25632670 |
| inducible genetic system for the axolotl. | transgenesis promises a powerful means for assessing gene function during amphibian limb regeneration. this approach is complicated, however, by the need for embryonic appendage development to proceed unimpeded despite the genetic alterations one wishes to test later in the context of regeneration. achieving conditional gene regulation in this amphibian has not proved to be as straightforward as in many other systems. in this report we describe a unique method for obtaining temporal control over ... | 2012 | 22869739 |
| foamy virus for efficient gene transfer in regeneration studies. | molecular studies of appendage regeneration have been hindered by the lack of a stable and efficient means of transferring exogenous genes. we therefore sought an efficient integrating virus system that could be used to study limb and tail regeneration in salamanders. | 2013 | 23641815 |
| pseudotyped retroviruses for infecting axolotl. | the ability to introduce dna elements into host cells and analyze the effects has revolutionized modern biology. here we describe a protocol to generate moloney murine leukemia virus (mmlv)-based, replication-incompetent pseudotyped retrovirus capable of infecting axolotls and incorporating genetic information into their genome. when pseudotyped with vesicular stomatitis virus (vsv)-g glycoprotein, the retroviruses can infect a broad range of proliferative axolotl cell types. however, if the ret ... | 2015 | 25740482 |
| vesicular stomatitis virus enables gene transfer and transsynaptic tracing in a wide range of organisms. | current limitations in technology have prevented an extensive analysis of the connections among neurons, particularly within nonmammalian organisms. we developed a transsynaptic viral tracer originally for use in mice, and then tested its utility in a broader range of organisms. by engineering the vesicular stomatitis virus (vsv) to encode a fluorophore and either the rabies virus glycoprotein (rabv-g) or its own glycoprotein (vsv-g), we created viruses that can transsynaptically label neuronal ... | 2015 | 25688551 |
| preparation of primary myogenic precursor cell/myoblast cultures from basal vertebrate lineages. | due to the inherent difficulty and time involved with studying the myogenic program in vivo, primary culture systems derived from the resident adult stem cells of skeletal muscle, the myogenic precursor cells (mpcs), have proven indispensible to our understanding of mammalian skeletal muscle development and growth. particularly among the basal taxa of vertebrata, however, data are limited describing the molecular mechanisms controlling the self-renewal, proliferation, and differentiation of mpcs ... | 2014 | 24835774 |
| genomics of a metamorphic timing qtl: met1 maps to a unique genomic position and regulates morph and species-specific patterns of brain transcription. | very little is known about genetic factors that regulate life history transitions during ontogeny. closely related tiger salamanders (ambystoma species complex) show extreme variation in metamorphic timing, with some species foregoing metamorphosis altogether, an adaptive trait called paedomorphosis. previous studies identified a major effect quantitative trait locus (met1) for metamorphic timing and expression of paedomorphosis in hybrid crosses between the biphasic eastern tiger salamander (am ... | 2013 | 23946331 |
| microarray analysis of a salamander hopeful monster reveals transcriptional signatures of paedomorphic brain development. | the mexican axolotl (ambystoma mexicanum) is considered a hopeful monster because it exhibits an adaptive and derived mode of development - paedomorphosis - that has evolved rapidly and independently among tiger salamanders. unlike related tiger salamanders that undergo metamorphosis, axolotls retain larval morphological traits into adulthood and thus present an adult body plan that differs dramatically from the ancestral (metamorphic) form. the basis of paedomorphic development was investigated ... | 2010 | 20584293 |
| acid-sensing ionic-channel functional expression in the vestibular endorgans. | in the vestibular system, the electrical discharge of the afferent neurons has been found to be highly sensitive to external ph changes, and acid-sensing ionic-channels (asic) have been found to be functionally expressed in afferent neurons. no previous attempt to assay the asic function in vestibular afferent neurons has been done. in our work we studied the electrical discharge of the afferent neuron of the isolated inner ear of the axolotl (ambystoma tigrinum) to determine the participation o ... | 2009 | 19660522 |
| amphibian sex determination: segregation and linkage analysis using members of the tiger salamander species complex (ambystoma mexicanum and a. t. tigrinum). | little is known about the genetic basis of sex determination in vertebrates though considerable progress has been made in recent years. in this study, segregation analysis and linkage mapping were performed to localize an amphibian sex-determining locus (ambysex) in the tiger salamander (ambystoma) genome. segregation of sex phenotypes (male and female) among the second generation individuals of interspecific crosses (ambystoma mexicanum x ambystoma tigrinum tigrinum) was consistent with mendeli ... | 2009 | 19259115 |
| mathematical model of the cupula-endolymph system with morphological parameters for the axolotl (ambystoma tigrinum) semicircular canals. | by combining mathematical methods with the morphological analysis of the semicircular canals of the axolotl (ambystoma tigrinum), a system of differential equations describing the mechanical coupling in the semicircular canals was obtained. the coefficients of this system have an explicit physiological meaning that allows for the introduction of morphological and dynamical parameters directly into the differential equations. the cupula of the semicircular canals was modeled both as a piston and ... | 2008 | 19593455 |
| nitric oxide in the amphibian (ambystoma tigrinum) lateral line. | nicotinamide adenine dinucleotide phosphate reduced-diaphorase (nadph-d) histochemistry was investigated in the axolotl (ambystoma tigrinum) lateral line. hair cells of neuromast organs of the head skin and neurons of the postotic ganglia showed a significant nadph-d reaction. multiunit recording of neuromast afferent activity was also performed. nitric oxide synthase inhibitor n omega-nitro-l-arginine methyl ester (l-name) produced an initial slight excitation followed by a significant inhibiti ... | 2006 | 16225991 |
| molecular characterization of major histocompatibility complex class ii alleles in wild tiger salamanders (ambystoma tigrinum). | major histocompatibility complex (mhc) class ii genes are usually among the most polymorphic in vertebrate genomes because of their critical role (antigen presentation) in immune response. prior to this study, the mhc was poorly characterized in tiger salamanders (ambystoma tigrinum), but the congeneric axolotl (ambystoma mexicanum) is thought to have an unusual mhc. most notably, axolotl class ii genes lack allelic variation and possess a splice variant without a full peptide binding region (pb ... | 2005 | 16195876 |
| a comprehensive expressed sequence tag linkage map for tiger salamander and mexican axolotl: enabling gene mapping and comparative genomics in ambystoma. | expressed sequence tag (est) markers were developed for ambystoma tigrinum tigrinum (eastern tiger salamander) and for a. mexicanum (mexican axolotl) to generate the first comprehensive linkage map for these model amphibians. we identified 14 large linkage groups (125.5-836.7 cm) that presumably correspond to the 14 haploid chromosomes in the ambystoma genome. the extent of genome coverage for these linkage groups is apparently high because the total map size (5251 cm) falls within the range of ... | 2005 | 16079226 |
| opioid receptors mediate a postsynaptic facilitation and a presynaptic inhibition at the afferent synapse of axolotl vestibular hair cells. | this study was designed to determine the effects of opiate drugs on the electrical activity of afferent neurons and on the ionic currents of hair cells from semicircular canals. experiments were done on larval axolotls (ambystoma tigrinum). the multiunit spike activity of afferent neurons was recorded in the isolated inner ear under both resting conditions and mechanical stimulation. ionic currents were recorded using voltage clamp of hair cells isolated from the semicircular canal. in the isola ... | 2003 | 12676139 |
| action mechanism of betahistine in the vestibular end organs. | betahistine has been used to treat several vestibular disorders of both central and peripheral origin. the objective of this work was to study the betahistine action mechanism at the vestibular end organs. experiments were carried out in wild larval axolotl (ambystoma tigrinum). multiunit extracellular recordings were obtained from the semicircular canal nerve using a suction electrode. betahistine (10 microm to 10 mm, n = 32) inhibited the basal spike discharge of the vestibular afferent neuron ... | 2001 | 11677837 |
| betahistine produces post-synaptic inhibition of the excitability of the primary afferent neurons in the vestibular endorgans. | betahistine has been used to treat several vestibular disorders of both central and peripheral origin. the objective of this work was to study the action of betahistine in the vestibular endorgans. experiments were done in wild larval axolotl (ambystoma tigrinum). multiunit extracellular recordings were obtained from the semicircular canal nerve using a suction electrode. betahistine (10 microm to 10 mm; n = 32) inhibited the basal spike discharge of the vestibular afferent neurons with an ic50 ... | 2001 | 11677735 |
| nitric oxide in the afferent synaptic transmission of the axolotl vestibular system. | this study was performed using intracellular and multiunit extracellular recording techniques in order to characterize the role of nitric oxide in the afferent synaptic transmission of the vestibular system of the axolotl (ambystoma tigrinum). bath application of nitric oxide synthase inhibitors n(g)-nitro-l-arginine (0.01microm to 10microm) and n-nitro-l-arginine methyl ester hydrochloride (0.1microm to 1000microm) elicited a dose-dependent decrease in the basal discharge of the semicircular ca ... | 2001 | 11246160 |
| cutaneous mastocytomas in the neotenic caudate amphibians ambystoma mexicanum (axolotl) and ambystoma tigrinum (tiger salamander). | spontaneous mastocytomas studied in 18 axolotls (ambystoma mexicanum) and six tiger salamanders (ambystoma tigrinum) were gray-white, uni- to multilobular cutaneous protrusions from 2 mm to 2 cm in diameter. tumors were moderately cellular unencapsulated masses that usually infiltrated the dermis and hypodermis with the destruction of intervening tissues. some tumors were invading superficial bundles of the underlying skeletal muscle. tumors consisted of mitotically active cells derived from a s ... | 1999 | 10235473 |
| antagonism of glutamate receptors by a chromatographic fraction from the exudate of the sea anemone phyllactis flosculifera. | in the search for new glutamate antagonists it seems promising to characterize the effects of venom from invertebrates that prey mainly on crustaceans. in this work, the exudate of the sea anemone phyllactis flosculifera was used as a source of this type of compound. the action of chromatographic fraction d from p. flosculifera was tested upon microion-tophoretically evoked glutamate responses in intracellular recordings from central neurons of the land snail zachrysia guanensis. bath applicatio ... | 1996 | 8735243 |
| histochemistry and role of nitric oxide synthase in the amphibian (ambystoma tigrinum) inner ear. | nicotinamide adenine dinucleotide phosphate reduced-diaphorase (nadph-d) histochemistry was investigated in the axolotl (ambystoma tigrinum) inner ear. hair cells showed an intense nadph-d reaction; afferent neurones also stained but less intensely than hair cells. effects of ng-nitro-l-arginine (l-noarg) on the basal discharge and mechanical responses of semicircular canal afferent neurones recorded extracellularly were also studied. l-noarg (1 mu m) diminished the basal discharge and the respo ... | 1996 | 8907334 |
| nmda-mediated potentiation of the afferent synapse in the inner ear. | in an isolated vestibular organ preparation from the axolotl (ambystoma tigrinum), glycine (10-0.01 microm) perfusion had no effect in the resting control condition, but significantly modified the response of afferent fibres to mechanical stimuli, producing a slowly increasing discharge rate during sinusoidal mechanical stimulation periods. this action was dependent upon the stimulus duration and was antagonized by 7-chloro-kynurenic acid (7-clkyn), 2-amino-5-phosphonopentanoic acid (ap5), n-all ... | 1994 | 7841385 |
| evidence for nmda receptor in the afferent synaptic transmission of the vestibular system. | this study aimed to define the pharmacology and physiological role of the n-methyl-d-aspartate (nmda) receptor in the synapse between the hair cells and primary afferent neurons in the vestibular system. the spontaneous and mechanically evoked spike discharges of vestibular nerve fibers were extracellularly recorded in isolated inner ear from the axolotl (ambystoma tigrinum). pressure ejection of nmda (10(-6) to 10(-3) m) elicited a dose-dependent increase of the basal spike discharge from the v ... | 1994 | 7907935 |
| proteolytic cleavage of acth in corticotropes of sexually mature axolotls (ambystoma mexicanum). | immunohistochemical analysis of the pituitary of sexually mature axolotls revealed both acth(1-39)-related and alpha-msh-related immunoreactivity present in corticotropic cells located in the rostral anterior pituitary. gel filtration analysis indicated that the acth(1-39)-sized immunoreactivity and the alpha-msh-sized immunoreactivity detected in acid extracts of the axolotl anterior pituitary were present in a ratio in a range between 1:1 and 1:0.6. reversed-phase hplc analyses indicated that ... | 2007 | 8284252 |
| streptomycin blocks the postsynaptic effects of excitatory amino acids on the vestibular system primary afferents. | it has been suggested that streptomycin might be an antagonist of the glutamate receptors, and that it selectively blocks quisqualic acid receptors. we studied whether streptomycin blocks the responses to excitatory amino acid agonists on the vestibular system primary afferents, and if it allows us to differentiate between kainate (ka) and quisqualate (qa) receptor mediated responses. the experiments were performed in the axolotl (ambystoma tigrinum). intra- and extracellular records of the elec ... | 1991 | 1786535 |
| banding differences between tiger salamander and axolotl chromosomes. | the hoechst 33258 - giemsa banding patterns were compared on axolotl (ambystoma mexicanum shaw) and axolotl - tiger salamander (ambystoma tigrinum green) species hybrid prophase chromosomes. approximately 369 bands per haploid chromosome set were seen in the axolotl and about 344 bands in the tiger salamander. in the haploid set of 14 chromosomes, chromosome 3 has a constant short or q-arm terminal constriction at the location of the nucleolar organizer. chromosomes 14 z and w carry the sex dete ... | 1985 | 4063874 |
| has prolactin an intermedin-like activity on the integument of the axolotl? | skin explants of the neotenic form of ambystoma tigrinum (axolotl) have been kept in culture during several days. when alpha-msh or prolactin are added to the medium, a dispersion of melanin in melanosomes is observed. the reaction is reversible in the case of prolactin when the explants are transferred in the medium without hormones. furthermore with prolactin, expansion of melanin in dermal melanophores is a more permanent and highly reproducible phenomenon, compared with the action of alpha-m ... | 1981 | 6176199 |
| allopurinol-induced melanism in the tiger salamander (ambystoma tigrinum nebulosum). | the enzyme, xanthine dehydrogenase (xdh), has been examined in ambystoma tigrinum nebulosum with respect to its role in pigmentation. it now seems probable that the melanoid gene (m) either codes directly for xdh or is somehow intimately connected with the normal function of this enzyme. inhibition of xdh using the drug, allopurinol, results in animals which appear to be phenocopies of melanoid mutants as described for the mexican axolotl (ambystoma mexicanum). the effects of allopurinol in term ... | 1979 | 490138 |
| pathologic changes in the ultrastructure of hepatocytes in the axolotl (ambystoma tigrinum green) under the influence of roentgen rays. | | 1971 | 5562662 |
| [effect of hormones as a function of the ph of the environment on metamorphosis and development of the axolotl (ambystoma tigrinum green)]. | | 1953 | 13142450 |
| [effect of combined hormonal treatment on the metamorphosis of the axolotl; ambystoma tigrinum green; as a function of the ph of the ambient medium]. | | 1953 | 13138988 |
| comparative and phylogenetic perspectives of the cleavage process in tailed amphibians. | the order caudata includes about 660 species and displays a variety of important developmental traits such as cleavage pattern and egg size. however, the cleavage process of tailed amphibians has never been analyzed within a phylogenetic framework. we use published data on the embryos of 36 species concerning the character of the third cleavage furrow (latitudinal, longitudinal or variable) and the magnitude of synchronous cleavage period (up to 3-4 synchronous cell divisions in the animal hemis ... | 2015 | 25180466 |
| lmx-1b and wnt-7a expression in axolotl limb during development and regeneration. | axolotls (ambystoma mexicanum) have the ability to regenerate amputated limbs throughout their life span. during limb regeneration as well as development, undifferentiated cells in the blastema acquire positional information to reproduce the original pattern along three cardinal limb axes: anteroposterior, proximodistal and dorsoventral. in the present study, we attempted to understand the molecular mechanism involved in patterning of axolotl limb development and regeneration along the dorsovent ... | 2013 | 23614984 |
| anatomy and forebrain projections of the olfactory and vomeronasal organs in axolotls (ambystoma mexicanum). | we examined the anatomy of the nasal cavity and forebrain in the axolotl (ambystoma mexicanum) to determine whether the olfactory and vomeronasal systems are present in this neotenic aquatic salamander. the current study was motivated by two considerations: (a) little is known of the anatomy of the vomeronasal system in aquatic vertebrates, and (b) the presence of both olfactory and vomeronasal systems in larval amphibians has broad implications for the evaluation of these systems in vertebrates ... | 1994 | 7953608 |
| phototaxic behavior and the retinotectal transport of horseradish peroxidase (hrp) in surgically created cyclopean salamander larvae (ambystoma). | negative phototaxis (np) was used to evaluate the recovery of vision in albino axolotl larvae with one eye discarded and the other transplanted either to the orbit (orthoclops) or to the top of the head (cyclops). np was assessed at approximately 1, 2 and 3 months postoperatively, using an automated, infrared monitor. some 88% of the orthoclopes and 64% of the cyclopes recovered np. however, among the cyclopes that did recover, the quantitative aspects of np were virtually the same as those of t ... | 1993 | 8134018 |
| spinal cord neuron classes in embryos of the smooth newt triturus vulgaris: a horseradish peroxidase and immunocytochemical study. | spinal cord neurons were investigated in embryos of triturus vulgaris, the smooth newt, just prior to hatching. these embryos can swim if freed from their egg membranes. horseradish peroxidase (hrp) labelling, together with gaba and glycine immunocytochemistry (icc), revealed nine distinct anatomical classes of neuron. 1. ventrolateral motoneurons with mainly dorsal dendrites, sometimes a descending central axon and peripheral axon innervating the trunk muscles. 2. dorsal primary sensory rohon-b ... | 1993 | 8099742 |
| homing behaviour of regenerating axons in the amphibian limb. | following peripheral nerve deviation in the limbs of urodele amphibians axons regrow distally toward their previous target muscles (holder et al. 1984; proc. roy. soc. lond. b 222, 477-489). this study describes analysis of this axon regeneration over time following deviation of the forearm flexor nerve in triturus cristatus and the extensor cranialis nerve in the axolotl. using horseradish peroxidase (hrp) axonal tracing, electrophysiology and electron microscopy, we describe the sequence of ev ... | 1989 | 2485244 |
| regeneration of descending axons in the spinal cord of the axolotl. | horseradish peroxidase was used to describe the positions and approximate numbers of neurones with axons that descend to the lumbar spinal cord in normal axolotls and axolotls whose spinal cord had been transected 3-23 months previously. three to 4 months after the transection approximately 10% of the axons had grown across the cut and returned to the lumbar spinal cord whereas 23 months after the transection the number and distribution of these cells were approaching those of the controls. | 1988 | 3399135 |
| reformation of specific neuromuscular connections during axolotl limb regeneration: evidence that the first contacts are correct. | retrograde neuronal tracing with horseradish peroxidase was used to determine the position in the spinal cord of the motor neurone pools of a proximal (biceps) and a distal (extensor digitorum) limb muscle at various times during axolotl limb regeneration. it was found that from the earliest stages of muscle redifferentiation (as judged by light and electron microscopic analysis) the vast majority of axons innervating the regenerating muscles came from cells within the bounds of the normal motor ... | 1988 | 3224559 |
| connections between the nucleus isthmi and the tectum in larval and post-metamorphic axolotls. | the nucleus isthmi (ni) is the primary relay for the frog's ipsilateral visuotectal projection. using electrophysiological methods, ipsilateral visuotectal activity has been recorded in thyroxine-treated, postmetamorphic axolotls but not in larval axolotls. in order to determine whether changes in isthmotectal projections are responsible for this change in electrophysiological responsiveness, we have investigated the connections between the tectum and the ni using horseradish peroxidase. our res ... | 1988 | 3351504 |
| reformation of the pattern of neuromuscular connections in the regenerated axolotl hindlimb. | retrograde neuronal tracing with horseradish peroxidase (hrp) was used to determine the position in the spinal cord of motor neurone pools innervating muscles in the regenerated axolotl hindlimb. this method allows a detailed analysis of the accuracy of reformation of neuromuscular connections. the results show that regenerated distal limb muscles are reinnervated by motor neurones in the same region of the cord as those that innervate normal control distal limb muscles but that proximal muscles ... | 1987 | 3652997 |
| motorneuron pools innervating muscles in vitamin a-induced proximal-distal duplicate limbs in the axolotl. | serially duplicated limbs containing two sets of proximal muscles were created in axolotls by vitamin a treatment. the innervation of three replicated proximal muscles was studied by using retrograde transport of horseradish peroxidase. these were the forelimb muscles biceps (seven cases) and anconeus (five cases) and the hindlimb muscle puboischiotibialis (five cases). in two cases (both of anconeus) innervation was from a correct motorneuron pool. in the other 15 cases the innervation was from ... | 1985 | 2410931 |
| a horseradish peroxidase study of motorneuron pools of the forelimb and hindlimb musculature of the axolotl. | motorneuron pools innervating axolotl limb muscles have been investigated by using the retrograde neuronal tracer horseradish peroxidase. four muscles in the forelimb (biceps, anconeus, flexor digitorum and extensor digitorum) and four functionally equivalent muscles in the hindlimb (puboischiotibialis, iliotibialis, flexor digitorum and extensor digitorum) were studied. motorneuron pools were characterized by using four criteria: position in the rostrocaudal axis; position of the median in the ... | 1985 | 2410930 |
| axonal pathfinding in the absence of normal pathways and impulse activity. | retinal axons were challenged to grow to their targets both along abnormal pathways and in the absence of impulse activity. eye primordia were first transplanted from normal to ectopic sites in axolotl embryos. most of the hosts were genetically eyeless, others were enucleated normal embryos. these axolotl embryos were then parabiotically joined to california newt embryos. both operations were completed by stage 28, which is before axons have left the eye. the result of the parabiosis was a para ... | 1984 | 6325605 |
| identification and morphometric evaluation of the synapses of optic nerve afferents in the optic tectum of the axolotl (ambystoma mexicanum). | ther terminals of retinal afferents in the tectum of the axolotl have been identified ultrastructurally using techniques of horseradish peroxidase-filling and degeneration. the mitochondria in filled structures show a characteristic electron-lucent matrix. after both eyes have been removed, terminals with light mitochondria disappear from the area known to receive an optic input. in this area the presence of light mitochondria is almost always diagnostic of the retinal origin of a bouton. the sy ... | 1981 | 7214469 |
| constant occurrence of an ipsilateral retino-tectal projection in the axolotl (ambystoma mexicanum) revealed by horseradish peroxidase tracing. | cut optic nerves were filled orthogradely with horseradish peroxidase (hrp) to reveal contralateral and ipsilateral retino-tectal projections in the axolotl, by light and electron microscopy. the ipsilateral projection is small but consistently present. it is concentrated in the rostral tectum particularly the dorsomedial and ventrolateral areas. the results are compared with findings in other vertebrates. | 1980 | 7052461 |
| lysophosphatidyl choline facilitates labeling of cns projections with horseradish peroxidase. | previously, it has been difficult to label sensory terminations in the cns by back-filling peripheral sensory nerves with horseradish peroxidase (hrp), apparently because the amount of hrp transported along the axons is insufficient. labeling of central sensory projections in axolotls and frogs can be improved by agents known to disrupt membranes. of those tested, l-alpha-lysophosphatidyl choline is the most effective. the addition of this detergent ot the hrp solution dramatically increases bot ... | 1980 | 6967137 |
| the regression of synapses formed by a foreign nerve in a mature axolotl striated muscle. | a study has been made of the factors which determine that the terminals of a foreign flexor nerve at synaptic sites in a unrodele extensor muscle regress on return of the original extensor nerve. the quantal content (m) of the endplate potential (epp) at flexor nerve terminal synapses, during innervation of a previously denervated extensor muscle, increased in about 8 weeks to reach the same size as at normal extensor nerve terminals; the same time was taken for m to reach normal size at extenso ... | 1979 | 487102 |
| regulation of axolotl (ambystoma mexicanum) limb blastema cell proliferation by nerves and bmp2 in organotypic slice culture. | we have modified and optimized the technique of organotypic slice culture in order to study the mechanisms regulating growth and pattern formation in regenerating axolotl limb blastemas. blastema cells maintain many of the behaviors that are characteristic of blastemas in vivo when cultured as slices in vitro, including rates of proliferation that are comparable to what has been reported in vivo. because the blastema slices can be cultured in basal medium without fetal bovine serum, it was possi ... | 2015 | 25923915 |
| melatonin levels in the gastrointestinal tissues of fish, amphibians, and a reptile. | melatonin was detected by radioimmunoassay in the gastrointestinal tract (git) of several species of fish (sturgeon, rainbow trout, carp), amphibians (axolotl, leopard frog, bullfrog), and one reptile (red-sided garter snake), which were sacrificed during the daytime. the highest levels of melatonin were detected in the snake [means = 1018 pg/g stomach, 328 pg/g proximal gut (pg), 511 distal gut (dg)] and carp (means = 102 pg/g stomach, 146 pg/g pg and 141 pg/g dg). lowest levels were found in t ... | 1997 | 9204376 |
| reptilian class i major histocompatibility complex genes reveal conserved elements in class i structure. | the polymerase chain reaction was used to isolate clones with class i major histocompatibility complex sequences from fish (carp), amphibian (axolotl), and two species of reptile (lizard and snake). the lizard and snake clones were used to isolate class i cdna clones. all the sequences showed the expected evolutionary relatedness. the carp and axolotl clones and one lizard cdna clone lacked the first cysteine in the alpha 3 domain which in other class i heavy chains forms an intradomain disulfid ... | 1992 | 1612650 |
| calcium-independent stimulation of glycogenolysis by arginine vasotocin and catecholamines in liver of the axolotl (ambystoma mexicanum) in vitro. | arginine vasotocin (avt) caused a concentration-dependent increase of glycogen phosphorylase alpha activity, breakdown of glycogen and release of glucose, when added to pieces of axolotl liver in organ culture. the concentration causing half-maximal response (ec50) was about 1 nmol/l. these actions of avt were unaffected by the adrenergic antagonists propranolol, yohimbine and prazosin, but were blocked by equimolar amounts of d(ch2)5tyr(me)avt, a synthetic antagonist of vasopressin. arginine va ... | 1986 | 3701246 |
| prominent role of prominin in the retina. | prominin molecules represent a new family of pentaspan membrane glycoproteins expressed throughout the animal kingdom. the name originates from its localization on membrane protrusion, such as microvilli, filopodia, lamellipodia, and microspikes. following the original description in mouse and human, representative prominin members were found in fish (e.g., danio rerio), amphibian (ambystoma mexicanum, xenopus laevis), worm (caenorhabditis elegans), and flies (drosophila melanogaster). mammalian ... | 2013 | 23161075 |
| identification of angiotensin i in several vertebrate species: its structural and functional evolution. | in order to delineate further the molecular evolution of the renin-angiotensin system in vertebrates, angiotensin i (ang i) has been isolated after incubation of plasma and kidney extracts of emu (dromiceus novaehollandiae), axolotl (ambystoma mexicanum), and sea lamprey (petromyzon marinus). the identified sequences were [asp1, val5, asn9] ang i in emu, [asp1, val5, his9] ang i in axolotl, and [asn1, val5, thr9] ang i in sea lamprey. these results confirmed the previous findings that tetrapods ... | 2004 | 14723880 |
| the genes coding for 4 snrnas of drosophila melanogaster: localization and determination of gene numbers. | four small nuclear rnas (snrnas) have been isolated from drosophila melanogaster flies. they have been characterized by base analysis, fingerprinting, and injection into axolotl oocytes. the size of the molecules and the modified base composition suggest that the following correlations can be made: snrna1 approximately u2-snrna; snrna2 approximately u3-snrna; snrna3 approximately u4-snrna; snrna4 approximately u6-snrna. the snrnas injected into axolotl oocytes move into the nuclei, where they ar ... | 1983 | 6191277 |
| evolving possibilities: post-embryonic axial elongation in salamanders with biphasic (eurcyea cirrigera, e. longicauda, e. quadridigitata) and paedomorphic life cycles (eurycea nana and ambystoma mexicanum). submitted acta zoologica. | typically the number of vertebrae an organism will have post-embryonically is determined during embryogenesis via the development of paired somites. our research investigates the phenomenon of post-embryonic vertebral addition in salamander tails. we describe body and tail growth, and patterns of postsacral vertebral addition and elongation in context with caudal morphology for four plethodontids (eurycea), and one ambystomatid. eurycea nana and a. mexicanum have paedomorphic life cycles; e. cir ... | 2012 | 24790225 |
| homology of the cranial vault in birds: new insights based on embryonic fate-mapping and character analysis. | bones of the cranial vault appear to be highly conserved among tetrapod vertebrates. moreover, bones identified with the same name are assumed to be evolutionarily homologous. however, recent developmental studies reveal a key difference in the embryonic origin of cranial vault bones between representatives of two amniote lineages, mammals and birds, thereby challenging this view. in the mouse, the frontal is derived from cranial neural crest (cnc) but the parietal is derived from mesoderm, plac ... | 2016 | 27853617 |
| evolution of the head-trunk interface in tetrapod vertebrates. | vertebrate neck musculature spans the transition zone between head and trunk. the extent to which the cucullaris muscle is a cranial muscle allied with the gill levators of anamniotes or is instead a trunk muscle is an ongoing debate. novel computed tomography datasets reveal broad conservation of the cucullaris in gnathostomes, including coelacanth and caecilian, two sarcopterygians previously thought to lack it. in chicken, lateral plate mesoderm (lpm) adjacent to occipital somites is a recent ... | 2016 | 27090084 |
| the evolution of basal progenitors in the developing non-mammalian brain. | the amplification of distinct neural stem/progenitor cell subtypes during embryogenesis is essential for the intricate brain structures present in various vertebrate species. for example, in both mammals and birds, proliferative neuronal progenitors transiently appear on the basal side of the ventricular zone of the telencephalon (basal progenitors), where they contribute to the enlargement of the neocortex and its homologous structures. in placental mammals, this proliferative cell population c ... | 2016 | 26732839 |
| resegmentation in the mexican axolotl, ambystoma mexicanum. | the segmental series of somites in the vertebrate embryo gives rise to the axial skeleton. in amniote models, single vertebrae are derived from the sclerotome of two adjacent somites. this process, known as resegmentation, is well-studied using the quail-chick chimeric system, but the presumed generality of resegmentation across vertebrates remains poorly evaluated. resegmentation has been questioned in anamniotes, given that the sclerotome is much smaller and lacks obvious differentiation betwe ... | 2014 | 24127283 |
| spatial distribution of prominin-1 (cd133)-positive cells within germinative zones of the vertebrate brain. | in mammals, embryonic neural progenitors as well as adult neural stem cells can be prospectively isolated based on the cell surface expression of prominin-1 (cd133), a plasma membrane glycoprotein. in contrast, characterization of neural progenitors in non-mammalian vertebrates endowed with significant constitutive neurogenesis and inherent self-repair ability is hampered by the lack of suitable cell surface markers. here, we have investigated whether prominin-1-orthologues of the major non-mamm ... | 2013 | 23723983 |
| anatomy of the pectoral and forelimb muscles of wildtype and green fluorescent protein-transgenic axolotls and comparison with other tetrapods including humans: a basis for regenerative, evolutionary and developmental studies. | the axolotl ambystoma mexicanum is one of the most used model organisms in evolutionary, developmental and regenerative studies, particularly because it can reconstitute a fully functional and complete forelimb/hindlimb. surprisingly, there is no publication that describes all the pectoral and forelimb muscles of this species or provides a comparative framework between these muscles and those of other model organisms and of modern humans. in the present paper we describe and illustrate all these ... | 2012 | 22957800 |
| cranial muscles in amphibians: development, novelties and the role of cranial neural crest cells. | our research on the evolution of the vertebrate head focuses on understanding the developmental origins of morphological novelties. using a broad comparative approach in amphibians, and comparisons with the well-studied quail-chicken system, we investigate how evolutionarily conserved or variable different aspects of head development are. here we review research on the often overlooked development of cranial muscles, and on its dependence on cranial cartilage development. in general, cranial mus ... | 2013 | 22780231 |
| mccrearamycins a-d, geldanamycin-derived cyclopentenone macrolactams from an eastern kentucky abandoned coal mine microbe. | four cyclopentenone-containing ansamycin polyketides (mccrearamycins a-d), and six new geldanamycins (gdms b-g, including new linear and mycothiol conjugates), were characterized as metabolites of streptomyces sp. ad-23-14 isolated from the rock creek underground coal mine acid drainage site. biomimetic chemical conversion studies using both simple synthetic models and gdm d confirmed that the mccrearamycin cyclopentenone derives from benzilic acid rearrangement of 19-hydroxy gdm, and thereby pr ... | 2017 | 28140487 |
| profiling neurotransmitter receptor expression in the ambystoma mexicanum brain. | ability to regenerate limbs and central nervous system (cns) is unique to few vertebrates, most notably the axolotl (ambystoma sp.). however, despite the fact the neurotransmitter receptors are involved in axonal regeneration, little is known regarding its expression profile. in this project, rt-pcr and qpcr were performed to gain insight into the neurotransmitter receptors present in ambystoma. its functional ability was studied by expressing axolotl receptors in xenopus laevis oocytes by eithe ... | 2013 | 23353105 |
| collagen reconstitution is inversely correlated with induction of limb regeneration in ambystoma mexicanum. | amphibians can regenerate missing body parts, including limbs. the regulation of collagen has been considered to be important in limb regeneration. collagen deposition is suppressed during limb regeneration, so we investigated collagen deposition and apical epithelial cap (aec) formation during axolotl limb regeneration. the accessory limb model (alm) has been developed as an alternative model for studying limb regeneration. using this model, we investigated the relationship between nerves, epid ... | 2012 | 22379987 |
| candidate gene analysis of metamorphic timing in ambystomatid salamanders. | although much is known about the ecological significance of metamorphosis and metamorphic timing, few studies have examined the underlying genetic architecture of these traits, and no study has attempted to associate phenotypic variation to molecular variation in specific genes. here we report on a candidate gene approach (cga) to test specific loci for a statistical contribution to variation in metamorphic timing. three segregating populations (sp1, sp2 and sp3) were constructed utilizing three ... | 2003 | 12694285 |
| surfactant proteins and cell markers in the respiratory epithelium of the amphibian, ambystoma mexicanum. | the respiratory tract is lined by diverse epithelial cell types whose morphology, gene expression and functions are highly specialized along the cephalo-caudal axis of the lung. pulmonary gas exchange, surface tension reduction, host defense, fluid and electrolyte transport are functions shared by various vertebrate species, each organism facing similar requirements for adaptation to air breathing. consistent with this concept, we have identified distinct respiratory epithelial cell populations ... | 2001 | 11369539 |
| ontogeny of neurohormonal peptides, serotonin, and nitric oxide synthase in the gastrointestinal neuroendocrine system of the axolotl (ambystoma mexicanum): an immunohistochemical analysis. | the ontogeny of the neurohormonal peptides vasoactive intestinal polypeptide (vip), neurotensin (nt), substance p (sp), calcitonin gene-related peptide (cgrp), gastrin/cholecystokinin (gas/cck), and somatostatin (som) as well as serotonin (ser) and nitric oxide synthase (nos) was investigated in the gastrointestinal tract of the urodele ambystoma mexicanum, the axolotl, using immunohistochemical techniques. the first regulatory substances to appear were sp, som, and ser that could be immunohisto ... | 2001 | 11161772 |
| neurohormonal peptides, serotonin, and nitric oxide synthase in the enteric nervous system and endocrine cells of the gastrointestinal tract of neotenic and thyroid hormone-treated axolotls (ambystoma mexicanum). | immunoreactivity against vasoactive intestinal polypeptide (vip), neurotensin (nt), substance p (sp), calcitonin gene-related peptide (cgrp), gastrin/cholecystokinin (gas/cck), somatostatin (som), serotonin (ser), and nitric oxide synthase (nos) was investigated in the gastrointestinal tract of the urodele ambystoma mexicanum, the axolotl, by the use of immunohistochemical techniques. the study also compares the distribution patterns and frequencies of the neurohormones, and nos in neotenic and ... | 1999 | 10398886 |
| development of locomotor behavior in wild type and spastic (sp/sp) axolotls, ambystoma mexicanum. | the homozygous recessive spastic mutant found in the mexican axolotl shows violent coiling and thrashing behavior when subjected to strong tactile or electrical stimulation. in order to establish the time of onset of the first behavioral manifestation of the spastic gene, an etiological analysis of the ontogeny of swimming behavior in mutants and wild type siblings was undertaken. the locomotor patterns shown by embryos in response to an electrical stimulus were analyzed quantitatively from the ... | 1975 | 1202151 |
| identification of mutant genes and introgressed tiger salamander dna in the laboratory axolotl, ambystoma mexicanum. | the molecular genetic toolkit of the mexican axolotl, a classic model organism, has matured to the point where it is now possible to identify genes for mutant phenotypes. we used a positional cloning-candidate gene approach to identify molecular bases for two historic axolotl pigment phenotypes: white and albino. white (d/d) mutants have defects in pigment cell morphogenesis and differentiation, whereas albino (a/a) mutants lack melanin. we identified in white mutants a transcriptional defect in ... | 2017 | 28127056 |
| transcriptional and phylogenetic analysis of five complete ambystomatid salamander mitochondrial genomes. | we report on a study that extended mitochondrial transcript information from a recent est project to obtain complete mitochondrial genome sequence for 5 tiger salamander complex species (ambystoma mexicanum, a. t. tigrinum, a. andersoni, a. californiense, and a. dumerilii). we describe, for the first time, aspects of mitochondrial transcription in a representative amphibian, and then use complete mitochondrial sequence data to examine salamander phylogeny at both deep and shallow levels of evolu ... | 2005 | 15780978 |
| axolotl mhc class ii beta chain: predominance of one allele and alternative splicing of the beta1 domain. | the axolotl mhc is composed of multiple polymorphic class i loci linked to class ii b loci. in this report, evidence of the existence of one class ii b locus (amme-dab) that codes for two different transcripts is given. a 2.1-kb transcript is translated to a complete beta chain and a shorter transcript of 1.8 kb encodes a molecule lacking the beta1 domain. for two complete class ii b mrna synthesized, up to one mrna devoid of the beta1 domain is synthesized. alternative splicing involving a pept ... | 2001 | 11180116 |
| candidate gene analysis of thyroid hormone receptors in metamorphosing vs. nonmetamorphosing salamanders. | we used two different experimental approaches to test the hypothesis that thyroid hormone receptor (tr) variation is associated with alternate life cycles modes in ambystomatid salamanders. in the first experiment, the inheritance of tralpha and trbeta genotypes was determined for metamorphic and non metamorphic offspring from backcrosses between ambystoma mexicanum (an obligate metamorphic-failure species) and metamorphic f1 hybrids (a. mexicanum x a. tigrinum tigrinum). the segregation of tr g ... | 2000 | 11012711 |
| the polytypic species revisited: genetic differentiation and molecular phylogenetics of the tiger salamander ambystoma tigrinum (amphibia: caudata) complex. | we present a phylogenetic analysis of the ambystoma tigrinum complex, based on approximately 840 base pairs of mitochondrial-dna sequence from the rapidly evolving d-loop and an adjacent intron. our samples include populations of the continentally distributed species, a. tigrinum, plus all described species of mexican ambystomatids. sequence divergence is low, ranging from 0-8.5%, and most phylogenetic groupings are weakly supported statistically. we identified eight reasonably well-defined clad ... | 1996 | 28568845 |
| studies on the effects of bleaching amphibian rod pigments in situ. i. the absorbance spectra of axolotl and tiger salamander rhodopsin and porphyropsin. | | 1978 | 639883 |
| albino axolotls from an albino tiger salamander through hybridization. | | 2003 | 6055330 |
| morphology and infectivity of cultivated trypanosoma ambystomae. | cultures of trypanosoma ambystomae were initiated and maintained in hypo-osmotic biphasic blood-agar medium. epimastigotes and trypomastigotes occurred in culture and although they were similar in size, epimastigotes predominated with about 70% of all stages. epimastigotes divided by equal binary fission and occasionally formed rosettes. cultured trypomastigotes did not divide. cultures isolated 118 days earlier were infective to all 3 laboratory-reared ambystoma jeffersonianum and to 2 of 3 amb ... | 1994 | 8064518 |
| responses to amputation of denervated ambystoma limbs containing aneurogenic limb grafts. | the developing neural tubes and associated neural crest cells were removed from stage 30 ambystoma maculatum embryos to obtain larvae with aneurogenic forelimbs. forelimbs were allowed to develop to late 3 digit or early 4 digit stages. limbs amputated through the mid radius-ulna regenerated typically in the aneurogenic condition. experiments were designed to test whether grafts of aneurogenic limb tissues would rescue denervated host limb stumps into a regeneration response. in experiment 1, an ... | 2003 | 12911114 |
| urodeles remove mesoderm from the superficial layer by subduction through a bilateral primitive streak. | urodeles begin gastrulation with much of their presumptive mesoderm in the superficial cell layer, all of which must move into the deep layers during development. we studied the morphogenesis of superficial mesoderm in the urodeles ambystoma maculatum, ambystoma mexicanum, and taricha granulosa. in all three species, somitic, lateral, and ventral mesoderm move into the deep layer during gastrulation, ingressing through a "bilateral primitive streak" just inside the blastopore. the mesodermal epi ... | 2002 | 12167400 |
| fibroblast growth factors in regenerating limbs of ambystoma: cloning and semi-quantitative rt-pcr expression studies. | urodele amphibians (newts and salamanders) have the ability to regenerate amputated limbs throughout their life span. because fibroblast growth factors (fgfs) play important roles in developing limbs, we initiated studies to investigate these growth factors in regenerating limbs. partial cdnas of fgf4, 8, and 10 were cloned from both the mexican axolotl, ambystoma mexicanum, and locally collected spotted salamander, ambystoma maculatum, two salamanders well recognized for their regenerative capa ... | 2001 | 11555861 |
| a test of the punctuated-cycling hypothesis in ambystoma forelimb regenerates: the roles of animal size, limb innervation, and the aneurogenic condition. | the punctuated-cycling (pc) hypothesis [39] predicts that the proportion of actively cycling (ac) cells within the blastema influences the rate of limb regeneration in urodele amphibians. to test this, we compared the rate of regeneration and the parameters of the pc hypothesis in small and large ambystoma mexicanum larvae and in aneurogenic limbs of ambystoma maculatum. aneurogenic limbs regenerated more slowly than limbs of small axolotls, but considerably faster than limbs of large axolotls. ... | 1987 | 3428513 |
| virtual genome walking across the 32 gb ambystoma mexicanum genome; assembling gene models and intronic sequence. | large repeat rich genomes present challenges for assembly using short read technologies. the 32 gb axolotl genome is estimated to contain ~19 gb of repetitive dna making an assembly from short reads alone effectively impossible. indeed, this model species has been sequenced to 20× coverage but the reads could not be conventionally assembled. using an alternative strategy, we have assembled subsets of these reads into scaffolds describing over 19,000 gene models. we call this method virtual genom ... | 0 | 29330416 |
| identification of regenerative roadblocks via repeat deployment of limb regeneration in axolotls. | axolotl salamanders are powerful models for understanding how regeneration of complex body parts can be achieved, whereas mammals are severely limited in this ability. factors that promote normal axolotl regeneration can be examined in mammals to determine if they exhibit altered activity in this context. furthermore, factors prohibiting axolotl regeneration can offer key insight into the mechanisms present in regeneration-incompetent species. we sought to determine if we could experimentally co ... | 2017 | 29302364 |
| limb regeneration in a direct-developing terrestrial salamander, bolitoglossa ramosi (caudata: plethodontidae): limb regeneration in plethodontid salamanders. | appendage regeneration is one of the most compelling phenomena in regenerative biology and is extensively studied in axolotls and newts. however, the regenerative capacity in other families of salamanders remains poorly described. here we characterize the limb regeneration process in bolitoglossa ramosi, a direct-developing terrestrial salamander of the plethodontid family. we (1) describe the major morphological features at different stages of limb regeneration, (2) show that appendage regenera ... | 2017 | 29299325 |
| transcriptional landscapes of axolotl (ambystoma mexicanum). | the axolotl (ambystoma mexicanum) is the vertebrate model system with the highest regeneration capacity. experimental tools established over the past 100 years have been fundamental to start unraveling the cellular and molecular basis of tissue and limb regeneration. in the absence of a reference genome for the axolotl, transcriptomic analysis become fundamental to understand the genetic basis of regeneration. here we present one of the most diverse transcriptomic data sets for axolotl by profil ... | 0 | 29291975 |
| reading and editing the pleurodeles waltl genome reveals novel features of tetrapod regeneration. | salamanders exhibit an extraordinary ability among vertebrates to regenerate complex body parts. however, scarce genomic resources have limited our understanding of regeneration in adult salamanders. here, we present the ~20 gb genome and transcriptome of the iberian ribbed newt pleurodeles waltl, a tractable species suitable for laboratory research. we find that embryonic stem cell-specific mirnas mir-93b and mir-427/430/302, as well as harbinger dna transposons carrying the myb-like proto-onco ... | 2017 | 29273779 |
| heart regeneration in adult xenopus tropicalis after apical resection. | myocardium regeneration in adult mammals is very limited, but has enormous therapeutic potentials. however, we are far from complete understanding the cellular and molecular mechanisms by which heart tissue can regenerate. the full functional ability of amphibians to regenerate makes them powerful animal models for elucidating how damaged mature organs are naturally reconstituted in an adult organism. like other amphibians, such as newts and axolotls, adult xenopus displays high regenerative cap ... | 2017 | 29255592 |
| regulation of regeneration by heparan sulfate proteoglycans in the extracellular matrix. | just as the building of a house requires a blueprint, the rebuilding of lost or damaged body parts through regeneration requires a set of instructions for the assembly of the various tissues into the right places. much progress has been made in understanding how to control the differentiation of different cell types to provide the building blocks for regeneration, such as bone, muscle, blood vessels and nerves/schwann cells. these are the cells that follow the blueprint (the pattern-following ce ... | 2017 | 29242821 |
| the axolotl limb regeneration model as a discovery tool for engineering the stem cell niche. | recent advances in genomics and gene editing have expanded the range of model organisms to include those with interesting biological capabilities such as regeneration. among these are the classic models of regeneration biology, the salamander. although stimulating endogenous regeneration in humans likely is many years away, with advances in stem cell biology and biomedical engineering (e.g. bio-inspired materials), it is evident that there is great potential to enhance regenerative outcomes by a ... | 2017 | 29230380 |