Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 |
| the third component of xenopus complement: cdna cloning, structural and functional analysis, and evidence for an alternate c3 transcript. | although the third component of complement has been purified from two amphibian species, xenopus laevis and the axolotl, only limited information is available about its primary structure in these species. we now present (a) 95% of the cdna sequence encoding c3 from a xenopus laevis/xenopus gilli (xenopus lg) hybrid (b) an analysis of the c3 convertase and factor i cleavage sites in xenopus c3, and (c) evidence for an alternative form of c3. the xenopus lg sequence has a 57% nucleotide and 52% am ... | 1995 | 7875221 |
| structure of the major neutral oligosaccharide-alditols released from the egg jelly coats of axolotl maculatum. characterization of the carbohydrate sequence galnac(beta 1-4)[fuc(alpha 1-3)] glcnac(beta 1-3/6). | several o-linked oligosaccharides of the jelly coat surrounding the eggs of axolotl maculatum were analysed by 1h-nmr spectroscopy. the four major oligosaccharidealditols released by reductive beta-elimination display either the lewisx (lex) determinant or the sequence galnac(beta 1-4)[fuc(alpha 1-3)]glcnac. this last structure has previously been characterized in allergenically active oligosaccharides isolated from the sea squirt h-antigen, and in the n-linked glycans of schistosoma mansoni and ... | 1994 | 7881174 |
| [characterization of cdna of t-cell receptor beta chain in rainbow trout]. | using a two-step pcr strategy, we have cloned several cdna segments encoding the t-cell receptor beta chain in a teleost fish, the rainbow trout (oncorhynchus mykiss). the nine clones analyzed encode identical n-terminal-truncated v beta regions which present limited sequence similarities with several mammalian tcr v beta chains, from residue tyr-35 to residue ser-95. these v beta regions are followed by v beta-d beta-j beta-like regions which are different in all the sequenced clones, and by id ... | 1994 | 7882160 |
| 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 |
| computations of post-inductive dynamics in axolotl heart formation. | this paper reports modelling of heart localization in the axolotl (ambystoma mexicanum). the region of heart specification in the mesoderm defined by classical induction from the endoderm is larger than the area of final myocardial differentiation. for localizing the area of differentiation within the area of specification, we postulate a reaction-diffusion system that arises within the mesoderm in response to induction from the endoderm. this mechanism generates a spatial pattern for two chemic ... | 1994 | 7949371 |
| 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 |
| evolution of t cell receptor genes. extensive diversity of v beta families in the mexican axolotl. | we have cloned 36 different rearranged variable regions (v beta) genes encoding the beta-chain of the t cell receptor in an amphibian species, ambystoma mexicanum (the mexican axolotl). eleven different v beta segments were identified, which can be classified into 9 families on the basis of a minimum of 75% nucleotide identity. all the cloned v beta segments have the canonical features of known mammalian and avian v beta, including conserved residues cys23, trp34, arg69, tyr90, and cys92. there ... | 1994 | 7963525 |
| immunofluorescent studies on titin and myosin in developing hearts of normal and cardiac mutant axolotls. | homozygous recessive cardiac mutant gene c in the axolotl, ambystoma mexicanum, results in a failure of the embryonic heart to initiate beating. previous studies show that mutant axolotl hearts fail to form sarcomeric myofibrils even though hearts from their normal siblings exhibit organized myofibrils beginning at stage 34-35. in the present study, the proteins titin and myosin are studied using normal (+/+) axolotl embryonic hearts at stages 26-35. additionally, titin is examined in normal (+/ ... | 1994 | 7966344 |
| organization of the serotoninergic system in the brain of two amphibian species, ambystoma mexicanum (urodela) and typhlonectes compressicauda (gymnophiona). | an immunocytochemical investigation was made of the distribution of serotonin (5-ht) in the brain of larval and adult ambystoma mexicanum and adult typhlonectes compressicauda. immunoreactive perikarya can be identified in the caudal diencephalon (paraventricular organ and infundibular nucleus), in the ventral mesencephalon (interpeduncular nucleus) and in the raphe of the rhombencephalon. immunopositive fibers and terminal arborizations are widely distributed, extending from the whole telenceph ... | 1994 | 7985815 |
| heart specification in the mexican axolotl (ambystoma mexicanum). | the concept of the morphogenetic field has been used extensively in developmental biology. however, little is known about the mechanisms that partition these broad areas of tissue into the smaller areas which actually form the corresponding structures, and the remaining tissue. in the mexican axolotl, the heart field forms as the anterior lateral plate mesoderm migrates over the underlying pharyngeal endoderm between stages 14 and 28. we have previously shown that both the mid-ventral and latera ... | 1994 | 7994078 |
| evolutionary conservation and molecular cloning of the recombinase activating gene 1. | a 700-bp fragment of the recombinase activating gene 1 (rag-1) was cloned from several evolutionarily distant (sandbar shark, paddlefish, goldfish, axolotl and pig) species using pcr. the nucleotide and deduced amino acid sequences revealed a highly conserved region that has remained essentially unaltered during 400 million years of evolution; e.g., shark and human sequences were 75% identical at the nucleic acid level and 87% as protein. the rag-1 mrna levels in the shark were analyzed using se ... | 1994 | 7999099 |
| cloning and expression of the axolotl proto-oncogene ski. | in vitro and in vivo overexpression studies have demonstrated that the c-ski proto-oncogene can influence proliferation, morphological transformation and myogenic differentiation. we report the isolation and expression of an axolotl (ambystoma mexicanum) c-ski (aski) gene. sequence analysis revealed a high degree of nucleotide and predicted amino acid (aa) homology with mammalian and anuran c-ski, showing the highest conservation to xenopus laevis c-ski (74% nucleotide and 87% aa). northern anal ... | 1995 | 7999783 |
| mitogen-activated axolotl (ambystoma mexicanum) splenocytes produce a cytokine that promotes growth of homologous lymphoblasts. | culture supernatants (pha-sns) from axolotl splenocytes cultured with phytohemagglutinin-p (pha) in medium supplemented with bovine serum albumin (bsa) were collected after 1, 2, and 3 days, pooled, treated to remove residual pha, precipitated with saturated ammonium sulfate, dialyzed, aliquoted, and stored at -20 degrees c. pha-sns stimulated proliferation of homologous lymphoblasts, but not resting splenocytes. sds-page of metabolically labeled pha-sns revealed a band between 14 and 21 kda. th ... | 1994 | 8001702 |
| development of lateral line organs in the axolotl. | lateral line sensory receptors and their cranial nerves in axolotls arise from a dorsolateral series of placodes, including the octaval placode, that gives rise to the inner ear and the octaval nerve. anterodorsal and anteroventral placodes occur rostral to the octaval placode and give rise to anterodorsal and anteroventral lateral line nerves and electroreceptors and mechanoreceptors of the snout, cheek, and lower jaw. middle, supratemporal, and posterior placodes occur caudal to the octaval pl ... | 1994 | 8006214 |
| multiple embryonic origins of gonadotropin-releasing hormone (gnrh) immunoreactive neurons. | experiments were conducted to test the hypothesis that gonadotropin-releasing hormone immunoreactive (gnrh-ir) and fmrfamide-ir neurons present in the brain and nervus terminalis originate in the embryonic olfactory placode. the olfactory placodes were bilaterally extirpated in stage 26 or stage 29 embryos of the axolotl, ambystoma mexicanum, which were then reared for 4-8 months before they were examined immunohistochemically. in experimental subjects with bilateral loss of olfactory epithelia, ... | 1994 | 8026083 |
| [fertilization and development of axolotl oocytes with already grey crescent experimentally formed during their maturation]. | pigmented axolotl coelomic oocytes were induced to form a gray crescent by simultaneous action of a gravity vector and of a heat-shock (36 +/- 0.5 degree c during 10-15 min), according to a previously described method. those oocytes were subsequently reintroduced into the coelomic cavity of an albino recipient female, which had been previously inseminated. among fertilized treated oocytes, more than 75% developed into embryos whose dorsal side corresponded to the gray crescent-forming area of th ... | 1993 | 8044696 |
| 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 |
| molecular cloning, sequencing and expression of an isoform of cardiac alpha-tropomyosin from the mexican axolotl (ambystoma mexicanum). | the cdna for alpha-tropomyosin (tm) was cloned by the polymerase chain reaction (pcr) from a lambda gt11 library constructed with mrna from juvenile axolotl heart tissues. subsequently, the nucleotide sequence of the cdna was determined. this is the first reported cdna for axolotl alpha-tropomyosin. comparative analyses of the deduced amino acid sequence of this cdna with xenopus skeletal muscle alpha-tropomyosin sequences indicate that the axolotl heart cdna has 93% and 96% homology in the regi ... | 1994 | 8074673 |
| pituitary-thyroid axis controls the final differentiation of the dorsal skeletal muscle in urodelan amphibians. | a histoenzymological study of the atpase activity of myosin in the dorsal axis muscle (dorsalis trunci) was carried out on two species of urodelan amphibians: pleurodeles waltlii, a euthyroid species with spontaneous metamorphosis and ambystoma mexicanum, a neotenic hypothyroid species. p. waltlii and a. mexicanum underwent an operation after which cytological analysis of the remaining pituitary were carried out in parallel. the muscle phenotype of urodelan amphibians varies according to the thy ... | 1994 | 8074999 |
| electrophysiological and behavioral studies of taste discrimination in the axolotl (ambystoma mexicanum). | electrophysiological and behavioral experiments were performed to determine whether the taste system of the aquatic salamander, axolotl, discriminates taste stimuli. taste responses were recorded extracellularly from the glossopharyngeal nerve bundle. the behavioral responses of axolotls towards various concentrations of nacl, kcl, citric acid, quinine-hydrochloride, and sucrose were quantified by measuring the ratio of rejection towards gel pellets, each containing either unitary stimuli or bin ... | 1994 | 8084890 |
| growth factor modulation of injury-reactive ependymal cell proliferation and migration. | injury-reactive ependymal cells from regenerating axolotl spinal cord can be maintained in their mesenchymal outgrowth phase in culture (o'hara et al., 1992). to address the ability of specific growth factors in stimulating or maintaining migration and proliferation, mesenchymal ependymal cell cultures derived from injured axolotl spinal cord at 2 weeks post-lesioning were used to determine the potential effects of epidermal growth factor, platelet-derived growth factor and transforming growth f ... | 1994 | 8091423 |
| plasma potassium may protect sodium pumps of toad hearts from an endogenous inhibitor. | resibufogenin (3-hydroxy-14,15-epoxy-20,22-dienolide glycoside) is a potent sodium pump inhibitor present in toad toxin. it is present in the skin of the cane toad (bufo marinus) at a concentration equivalent to ouabain of approximately 1 mm. because toads, like other amphibians, have permeable skin, resibufogenin is also found in high concentrations in the blood. in the cane toad the blood concentration is estimated to be 1 microm (d. lichtstein, s. kachalsky, and j. deutsch. life sci. 38: 1261 ... | 1994 | 8092319 |
| 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 |
| asymmetric effects of retinoic acid on pattern formation in the transverse axes of regenerating axolotl limbs: test of a hypothesis. | 1993 | 8115389 | |
| stage-dependent effects of retinoic acid on the regenerating limbs of larval korean salamander, hynobius leechii, at two amputation levels. | the morphological and biochemical data obtained in this series of experiments clearly confirm the previous finding about the relationship between the stage of limb regeneration and the effects of ra on duplication, i.e., the most sensitive stage for ra-induced duplication is the stage of dedifferentiation, regardless of the level of amputation. however, when the ra effects were expressed as a function of time after amputation, the upper arm regenerates clearly showed a prolonged and delayed resp ... | 1993 | 8115390 |
| 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 |
| retinoic acid gradients during limb regeneration. | retinoids have been implicated in pattern formation processes in both developing chick limbs and in the regenerating limbs of urodele amphibians as well as in other aspects of embryonic development. since chick wing buds have been shown to have a higher concentration of all-trans-retinoic acid (ra) in the posterior region than in the anterior region, we set out to look for a gradient of ra in the regenerating limb of the axolotl, ambystoma mexicanum. we used high-performance liquid chromatograph ... | 1994 | 8150219 |
| furrowing surface contraction wave coincident with primary neural induction in amphibian embryos. | we predicted, and have now observed, a surface contraction wave in axolotl (ambystoma mexicanum) embryos that appears to coincide temporally and spatially with primary neural induction and homoiogenetic induction, and with involution of the chordomesoderm. the wave starts from a focus anterior to the dorsal lip of the blastopore and spreads as an ellipse, until part of it encounters the rim of the blastopore and vanishes there. the remaining arc then continues over the dorsal hemisphere until it ... | 1994 | 8158657 |
| characterization of a multimeric polypeptide complex on the surface of thymus-derived cells in the mexican axolotl. | we previously raised a rabbit antiserum (l12) against a 38 kd polypeptide which is expressed on the surface of thymocytes and peripheral t cells of an urodele amphibian, the mexican axolotl (ambystoma mexicanum). here we show that l12 antibodies immunoprecipitate several labelled molecules from surface iodinated axolotl spleen cells, including the 38 kd molecule, but also two polypeptides of 43 and 22 kd which are covalently linked to other elements. another rabbit antiserum (l10) was raised aga ... | 1993 | 8211000 |
| receptors for atrial natriuretic factor (anf) in kidney and adrenal tissue of urodeles--lack of angiotensin ii (a ii) receptors in these tissues. | binding sites for atrial natriuretic factor (anf) and angiotensin ii (a ii) were localized and quantified in renal and adrenal tissue of the urodele ambystoma mexicanum by quantitative in vitro autoradiography using 125i-ratanf(99-126) and 125i-[val5]-a ii or 125i-human a ii as labeled ligands. specific 125i-ratanf(99-126) binding was present in glomeruli, renal tubules, and adrenal tissue. anf had heterogeneous binding sites exhibiting positive cooperativity with a half maximal binding concentr ... | 1993 | 8224766 |
| hormone-induced rise in cytosolic ca2+ in axolotl hepatocytes: extracellular origin and control by camp. | in amphibian liver, signal transduction of [arg8]vasotocin (avt), a "classical" ca(2+)-dependent hormone in rat liver, is mediated via the generation of adenosine 3',5'-cyclic monophosphate (camp) and not via inositol 1,4,5-trisphosphate [ins(1,4,5)p3]. in isolated hepatocytes from axolotl, hormones that stimulated camp formation (the order of efficacy was glucagon > isoprenaline > epinephrine > or = avt) also provoked a pronounced increase in cytosolic ca2+, as indicated from changes in fura 2 ... | 1993 | 8238480 |
| retinoic acid treatment inhibits mitosis in the pre-existing spinal cord during tail regeneration of the axolotl larva, ambystoma mexicanum. | during tail regeneration in the axolotl larva, ambystoma mexicanum, retinoic acid reduced mitosis some 10-fold in the pre-existing spinal cord. this conclusion followed from comparisons of mitotic indices in the central grey matter of spinal cords, proximal to the amputation plane, of animals intracoelomically injected with (a) retinoic acid 2 days before amputation and the mitotic inhibitor, demecolcine 5 h before sacrifice; or (b) as for the latter but without retinoic acid; or (c) only the so ... | 1993 | 8243113 |
| reaction-diffusion control of heart development: evidence for activation and inhibition in precardiac mesoderm. | in axolotl embryos homozygous for the cardiac-lethal (c) gene, the heart never begins to beat. recently, we demonstrated that the c gene affects the heart mesoderm directly, making the latter incapable of responding to normal inductive stimuli. based on these results, we proposed that a reaction-diffusion mechanism controls the later stages of vertebrate cardiogenesis. in the present study, we use a series of transplantations to examine the precardiac mesoderm of wild-type and cardiac-lethal mut ... | 1993 | 8253281 |
| fluorescent dye (dii) reveals the sensory cells in the lingual epithelium: a confocal laser scanning microscopic study. | fluorescent carbocyanine dye was applied to the glossopharyngeal nerve of axolotls fixed with paraformaldehyde. three cell types in the lingual epithelium were transneuronally labeled: chemosensory taste receptor cells and presumably mechanosensory basal cells in the taste buds, and epithelial cells with unknown function in the non-taste lingual epithelium. | 1993 | 8271492 |
| 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 |
| the development of the neural crest in amphibians. | our review deals with the development of the neural crest (nc) in amphibians. we will consider relevant aspects of evolution, ontogeny, migration and differentiation, and investigate principal problems such as the regulation of nc cell determination, pathway selection and destination recognition. earlier data and more recent findings will be presented. the nc probably evolved about 440 million years ago from the anlagen of epidermal nerve plexuses in protochordates. in urodele amphibians, the pr ... | 1993 | 8297037 |
| analysis of the mutant axolotl short toes. | 1993 | 8302893 | |
| development and regeneration of limbs in the short toes axolotl mutant. | 1993 | 8302894 | |
| affinophoresis as a test of axolotl accessory limbs. | 1993 | 8302896 | |
| test of a model for the effects of retinoic acid on urodele limb regeneration. | previous studies have shown that in axolotls (ambystoma mexicanum), retinoic acid (ra) treatment evokes pattern completion in limb regenerates derived from anterior and dorsal half zeugopodia (lower arms and legs), but causes regenerative failure in posterior and ventral half zeugopodia. pattern completion in anterior and dorsal half limbs may be explained by postulating that intercalary regeneration occurs in the antero-posterior (ap) and dorsoventral (dv) axes between blastema cells that are p ... | 1993 | 8305708 |
| pit organs in axolotls: a second class of lateral line neuromasts. | the lateral line system of axolotls (ambystoma mexicanum) consists of mechanoreceptive neuromasts and electroreceptive ampullary organs. all neuromasts in salamanders are located superficially and are organized into lines that are homologous to canal neuromasts in fishes. ampullary organs are confined to the head and generally are located adjacent to the lines of superficial neuromasts. axolotls, however, also possess a third class of receptors; these form restricted patches on the head and are ... | 1993 | 8315607 |
| transcellular labeling by dii demonstrates the glossopharyngeal innervation of taste buds in the lingual epithelium of the axolotl. | innervation of the axolotl lingual epithelium by the glossopharyngeal nerve was examined to reveal its sensory target cells. the carbocyanine dye dii was applied to the nerve stump in the tongue fixed with paraformaldehyde. after a diffusion period of several months, the tongues were examined with a conventional epifluorescence microscope and a confocal laser scanning microscope (lsm) in wholemounts or preparations sectioned with a vibratome. beneath the epithelium the labeled nerve fibers sprea ... | 1993 | 8320345 |
| macrophage response during axonal regeneration in the axolotl central and peripheral nervous system. | we have used a monoclonal antibody (5f4) and griffonia lectin to study the recruitment of macrophages after crushing axolotl central and peripheral axons. in both cases axonal regeneration begins within one to two days and, in the cns, proceeds at a rate of about 0.05 mm per day. however, in the spinal cord, macrophage entry is restricted to the lesion site whilst in peripheral nerves macrophages rapidly enter the distal nerve stump after injury. these results suggest that the role (if any) play ... | 1993 | 8332261 |
| conserved structure of amphibian t-cell antigen receptor beta chain. | all jawed vertebrates possess well-differentiated thymuses and elicit t-cell-like cell-mediated responses; however, no surface t-cell receptor (tcr) molecules or tcr genes have been identified in ectothermic vertebrate species. here we describe cdna clones from an amphibian species, ambystoma mexicanum (the mexican axolotl), that have sequences highly homologous to the avian and mammalian tcr beta chains. the cloned amphibian beta chain variable region (v beta) shares most of the structural char ... | 1993 | 8341702 |
| restoration of motor unit properties and fiber type distribution in reinnervated axolotl skeletal muscle. | the contractile properties of functionally isolated motor units and the muscle fiber type distribution of reinnervated iliotibialis posterior muscles were examined in axolotls (ambystoma mexicanum) 7 to 12 months after complete transection of the hind limb nerve trunks. motor units were continuously distributed with respect to size and contractile speeds and there was a positive correlation between motor unit size and twitch:tetanus ratio. the degree of overlap between motor units was positively ... | 1993 | 8344452 |
| phylogeny of immunoglobulin heavy chain isotypes: structure of the constant region of ambystoma mexicanum upsilon chain deduced from cdna sequence. | an rna polymerase chain reaction strategy was used to amplify and clone a cdna segment encoding for the complete constant part of the axolotl igy heavy (c upsilon) chain. c upsilon is 433 amino acids long and organized into four domains (c upsilon 1-c upsilon 4); each has the typical internal disulfide bond and invariant tryptophane residues. axolotl c upsilon is most closely related to xenopus c upsilon (40% identical amino acid residues) and c upsilon 1 shares 46.4% amino acid residues among t ... | 1993 | 8344718 |
| metamorphic changes in glycolipids and myelin proteins and 2',3'-cyclic nucleotide 3'-phosphohydrolase in bullfrog and axolotl brains. | the metamorphic changes in levels of glycolipids and myelin proteins and 2',3'-cyclic nucleotide 3'-phosphohydrolase (cnp) in the brains of bullfrog tadpoles, adult frogs, and axolotls were investigated, with particular emphasis on myelin maturation. the concentrations of cerebroside, sulfatide, and galactosyldiacylglycerol gradually increased from the onset of prometamorphosis throughout the active metamorphic period and then greatly increased after metamorphosis was completed. the ratio of glu ... | 1993 | 8386225 |
| replacement of lateral line sensory organs during tail regeneration in salamanders: identification of progenitor cells and analysis of leukocyte activity. | it has been proposed that supporting cells may be the progenitors of regenerated hair cells that contribute to recovery of hearing in birds, but regeneration is difficult to visualize in the ear, because it occurs deep in the skull. hair cells and supporting cells that are comparable to those in the ear are present in lateral line neuromasts, and in axolotl salamanders these cells are accessible to microscopic observation in vivo. after amputation of a segment of the tail that contains neuromast ... | 1993 | 8441001 |
| isolation of cdnas for two closely related members of the axolotl wnt family, awnt-5a and awnt-5b, and analysis of their expression during development. | to characterize molecular interactions between cells in the early amphibian embryo, we have isolated cdnas for two members of the axolotl (ambystoma mexicanum) wnt family, awnt-5a and awnt-5b. the encoded proteins share 83% amino acid identity. using a reverse transcription-polymerase chain reaction (rt-pcr) assay, we find that awnt-5a transcripts are abundant in the blastula until gastrulation, barely detectable during gastrulation, and increase again during neurulation. they are detected throu ... | 1993 | 8443107 |
| immunocytochemical identification of serotonin-synthesizing neurons in the vertebrate retina: a comparative study. | serotonin-synthesizing neurons in the retinas of goldfish, axolotl, turtle, chick, rabbit and cat were identified using double labelling with anti-serotonin and anti-phenylalanine hydroxylase antibodies. the latter antibody recognizes tryptophan 5-hydroxylase, one of the synthesizing enzymes for serotonin. neurons labelled by both markers were considered to be serotonin-synthesizing neurons, while those only with serotonin-immunoreactivity were assumed to be serotonin-accumulating neurons. in th ... | 1993 | 8462655 |
| afferent and efferent connections of the thalamic eminence in the axolotl, ambystoma mexicanum. | afferent and efferent connections of the thalamic eminence of the axolotl were determined using the fluorescent compound dii as a tracer. the thalamic eminence is connected reciprocally with a number of telencephalic and diencephalic areas, particularly with the medial pallium, the amygdala and the preoptic region. efferent connections are widespread throughout the ipsilateral diencephalon. these findings are discussed in relation to the homology of this nucleus, especially its homologue in agna ... | 1993 | 8474688 |
| brachially innervated ectopic hindlimbs in the chick embryo. i. limb motility and motor system anatomy during the development of embryonic behavior. | the functional status of brachially innervated hindlimbs, produced by transplanting hindlimb buds of chick embryos in place of forelimb buds, was quantified by analyzing the number and temporal distribution of spontaneous limb movements. brachially innervated hindlimbs exhibited normal motility until e10 but thereafter became significantly less active than normal limbs and the limb movements were more randomly distributed. contrary to the findings with axolotls and frogs, functional interaction ... | 1993 | 8492107 |
| molecular analysis of the wnt-1 proto-oncogene in ambystoma mexicanum (axolotl) embryos. | to analyze wnt-1 expression during neurulation in urodele embryos, we have isolated a wnt-1 cdna clone, awnt-1, from an ambystoma mexicanum (axolotl) neurula-stage cdna library. awnt-1 codes for a protein of 369 amino acids rich in cysteine residues, is preceded by a hydrophobic leader peptide sequence and contains four possible sites for n-linked glycosylation. the temporal expression profile of awnt-1 was analyzed by reverse transcription-polymerase chain reaction (rt-pcr). awnt-1 expression i ... | 1993 | 8508949 |
| regeneration of sensory cells after laser ablation in the lateral line system: hair cell lineage and macrophage behavior revealed by time-lapse video microscopy. | the regeneration of sensory hair cells in lateral line neuromasts of axolotls was investigated via nearly continuous time-lapse microscopic observation after all preexisting hair cells were killed by a laser microbeam. the laser treatments left neuromasts with one resident cell type, which was supporting cells. over the course of 1 week, replacement hair cells arose either directly via differentiation of cells present in the epithelium from the beginning of the time-lapse period or via the devel ... | 1996 | 8551349 |
| characterization of an ultraviolet photoreception mechanism in the retina of an amphibian, the axolotl (ambystoma mexicanum). | spectral sensitivity measurements from the retina of the mexican salamander ambystoma mexicanum (the 'axolotl') were used to provide evidence for and to characterize an amphibian ultraviolet-sensitive photoreception mechanism. electroretinograms (transretinal voltage responses) were recorded from open eye cup preparations to analyze the spectral sensitivity of the retina. both dark-adapted and white light-adapted preparations exhibited a peak in sensitivity between 360-370 nm. under selective ch ... | 1995 | 8552288 |
| activin a and transforming growth factor-beta stimulate heart formation in axolotls but not rescue cardiac lethal mutants. | in the mexican axolotl (salamander), ambystoma mexicanum, a recessive cardiac lethal mutation causes an incomplete differentiation of the myocardium. mutant hearts lack organized sarcomeric myofibrils and do not contract throughout their lengths. we have previously shown that rna purified from normal anterior endoderm or from juvenile heart tissue is able to rescue mutant embryonic hearts in an in vitro organ culture system. under these conditions as many as 55% of formerly quiescent mutant hear ... | 1995 | 8565053 |
| confocal microscopy of a newly identified protein associated with heart development in the mexican axolotl. | recessive mutant gene c for "'cardiac nonfunction" in the mexican axolotl, ambystoma mexicanum, results in a failure of affected embryos to develop contracting hearts. mutant embryos survive approximately 4 weeks after fertilization, but eventually die from a lack of circulation. morphological studies show that mutant hearts lack organized sarcomeric myofibrils. this abnormality can be corrected by co-culturing early mutant hearts with normal anterior endoderm/mesoderm tissues, by culturing them ... | 1995 | 8581063 |
| immunohistochemical analysis of c-protein isoforms in cardiac and skeletal muscle of the axolotl, ambystoma mexicanum. | of the several proteins located within sarcomeric a-bands, c-protein, a myosin binding protein (mybp) is thought to regulate and stabilize thick filaments during assembly. this paper reports the characterization of c-protein isoforms in juvenile and adult axolotls, ambystoma mexicanum, by means of immunofluorescent microscopy and western blot analyses. c-protein and myosin are found specifically within the a-bands, whereas tropomyosin and alpha-actin are detected in the i-bands of axolotl myofib ... | 1995 | 8581934 |
| in vivo protein synthesis in developing hearts of normal and cardiac mutant axolotls (ambystoma mexicanum). | recessive mutant gene c in axolotls causes a failure of the hearts of affected embryos to function. the mutant hearts (c/c) lack organized sarcomeric myofibrils. the present study was undertaken to determine the overall pattern of in vivo protein synthesis and subsequent accumulation of the newly synthesized proteins for a 24-h period in normal (+/+ or +/c) and cardiac mutant (c/c) axolotl hearts at various stages of development. additionally, selected cytoskeletal/myofibrillar proteins were ana ... | 1995 | 8589758 |
| the epidermis is a source of directional information for the migrating pronephric duct in ambystoma mexicanum embryos. | in the urodele ambystoma mexicanum, the pronephric duct (pnd) is formed from a coherent group of cells that migrate from the pronephros to the cloaca along a pathway immediately ventral to the developing somites. the guidance cues used by the migrating pnd primordium to find the cloaca are a local property of the migration substratum, are temporally regulated, and are both polarized and oriented. since the pronephric duct migrates between two tissues--the underlying lateral mesoderm and the over ... | 1995 | 8612962 |
| embryonic taste buds develop in the absence of innervation. | it has been hypothesized that taste buds are induced by contact with developing cranial nerve fibers late in embryonic development, since descriptive studies indicate that during embryonic development taste cell differentiation occurs concomitantly with or slightly following the advent of innervation. however, experimental evidence delineating the role of innervation in taste bud development is sparse and equivocal. using two complementary experimental approaches, we demonstrate that taste cells ... | 1996 | 8620837 |
| identification of cdna clones encoding hmg 2, a major protein of the mexican axolotl hydrocortisone-sensitive thymocytes. | we have identified and analyzed cdna clones encoding a major 26 kda protein of the hmg1-2 family which is abundant in the cytoplasm and nucleus of axolotl hydrocortisone-sensitive thymocytes. the axolotl hmg2 protein is very similar to proteins belonging to the hmg1-2 family, from teleost fish to mammals. all the molecular features of the hmg1-2 proteins are conserved, including the high proportion of basic and aromatic residues, and the characteristic acidic c-terminus tail. the 3'-untranslated ... | 2003 | 8654668 |
| hard tissue of teeth and their calcium and phosphate content in ambystoma mexicanum (urodela: ambystomatidae). | the wall of the pulp cavity, fracture faces and the demineralized surfaces of teeth from larvae and adults of ambystoma mexicanum were investigated by scanning electron microscopy (sem). calcium and phosphate contents were determined by microanalysis. the apical part of the tooth (crown, tooth apex) contains dentin canals. in the larva, these do not reach the enamel-dentin border but end below this border in front of a denser hard substance, possibly enameloid. the pedicel in the adult and the b ... | 1996 | 8717330 |
| 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 |
| neural crest cell migration and pigment pattern formation in urodele amphibians. | this review deals with research on the development and differentiation of the neural crest (nc) in amphibians carried out during the past twenty years. first, earlier studies on the migration and differentiation of nc cells in vitro are summarized. these studies include the modes of nc cell migration and their differentiation into chondroblasts, perichondral cells, neurons, schwann cells and pigment cells (melanophores and xanthophores). then a summary is given on the development of cranial sens ... | 1996 | 8735933 |
| nucleotide sequence and expression of ribosomal protein s3 mrna during embryogenesis in the mexican axolotl (ambystoma mexicanum). | we have isolated and sequenced a full-length (0.9 kb) cdna clone of ribosomal protein s3 by subtraction hybridization using a single-stranded cdna library from stage 25-27 (tracer) and the mrna from stage 15-17 (driver) of embryonic mexican axolotl (ambystoma mexicanum). the axolotl is a unique animal model for studying heart development as well as myofibrillogenesis because it carries a mutation in gene c. the deduced amino acid sequence of axolotl s3 protein shows about 93.9% identity with hum ... | 1996 | 8739028 |
| distribution of keratan sulphate and chondroitin sulphate in wild type and white mutant axolotl embryos during neural crest cell migration. | in embryos of the white mutant axolotl, prospective pigment cells are unable to migrate from the neural crest (nc) due to a deficiency in the subepidermal extracellular matrix (ecm). this raises the question of the molecular nature of this functional defect. some pgs can inhibit cell migration on ecm molecules in vitro, and an excess of this class of molecules in the migratory pathways of neural crest cells might cause the restricted migration of prospective pigment cells seen in the white mutan ... | 1996 | 8739556 |
| effects of extracellular matrix molecules on subepidermal neural crest cell migration in wild type and white mutant (dd) axolotl embryos. | migration of neural crest (nc) derived pigment cells is restricted in the white mutant (dd) axolotl embryo (ambystoma mexicanum). transplantations between mutant and wild type embryos show that the extracellular matrix (ecm) of the white mutant is unable to support the migration of prospective pigment cells in wild type embryos (löfberg et al., 1989, dev. biol. 131:168-181). in the present study, we test the effects of various purified ecm molecules on nc cell migration in the subepidermal migra ... | 1996 | 8739557 |
| the structure, rearrangement, and ontogenic expression of db and jb gene segments of the mexican axolotl t-cell antigen receptor beta chain (tcrb). | we sequenced a total of 189 independent rearrangements in which the vb7.1 element is associated with cb1 (99 clones) or cb2 (90 clones) isotypes of the t-cell receptor (tcr) beta chain in the mexican axolotl. three stages of development were analyzed: 2.5 months, 10 months, and 25 months. three jb1 segments were associated with the vb-cb1 rearrangements and six jb2 segments with vb-cb2. as in other vertebrates, some amino acid positions were conserved in all jbetas (e. g., phe-108, gly-109, gly- ... | 1996 | 8753858 |
| the cardiac mutant gene c in axolotls: cellular, developmental, and molecular studies. | the cardiac mutant axolotl is an interesting model for studying heart development. the mutant gene results in a failure of heart cells to form organized myofibrils and as a consequence the heart fails to beat. experiments have shown that mutant hearts can be "rescued" (i.e., turned into normally contracting organs) by the addition of rna purified from conditioned media produced by normal embryonic anterior endoderm-mesoderm cultures. these corrected hearts form myofibrils of normal morphology. n ... | 1995 | 8775986 |
| differential expression of c-protein isoforms in the developing heart of normal and cardiac lethal mutant axolotls (ambystoma mexicanum). | regulated assembly of contractile proteins into sarcomeric structures, such as a- and i-bands, is still currently being defined. the presence of distinct isoforms of several muscle proteins suggests a possible mechanism by which myocytes regulate assembly during myofibrillogenesis. of several muscle isoforms located within the a-band, myosin binding proteins (mybp) are reported to be involved in the regulation and stabilization of thick filaments during sarcomere assembly. the present confocal s ... | 1996 | 8834470 |
| surface contraction and expansion waves correlated with differentiation in axolotl embryos. ii. in contrast to urodeles, the anuran xenopus laevis does not show furrowing surface contraction waves. | we have observed a number of contraction waves traversing the axolotl (ambystoma mexicanum) embryo (a urodelan amphibian) from the midblastula transition up to at least neural tube closure, and wished to learn if similar "differentiation waves" appear on the popular laboratory anuran amphibian, the south african clawed toad, xenopus laevis. time lapse video microscopy showed that no contraction waves are visible on the surface of xenopus from gastrulation through neurulation. it is possible that ... | 1996 | 8877438 |
| what mechanisms control neoteny and regulate induced metamorphosis in urodeles? | the mexican axolotl, like a number of other urodele species, is an obligatory neotene, completing its full life cycle without metamorphosis. metamorphosis can be induced with thyroid hormone, thyroid stimulating hormone, or stimulation of hypothalamic neurons. thus, neoteny represents a deviation from the standard course of amphibian ontogeny, affecting the thyroid axis at one or more levels. analysis of the thyroid axis at strategic ontogenic stages and after completed neotenic development sugg ... | 1996 | 8877439 |
| what insights into vertebrate pigmentation has the axolotl model system provided? | amphibians have been judiciously exploited by developmental biologists for many years for studying basic developmental mechanisms in vertebrates. in this review, the contributions that have been made by urodeles, in particular the axolotl (ambystoma mexicanum), to the study of pigment cell biology are elaborated. pigment cell differentiation is described, and the wild-type pigment phenotype is contrasted to pigment mutants such as albino, axanthic, melanoid, and white. methods used for studying ... | 1996 | 8877441 |
| morphogenesis of the axolotl pronephric duct: a model system for the study of cell migration in vivo. | pronephric duct (pnd) morphogenesis is a critical early event in the development of the vertebrate excretory system. this structure is the exit channel for both pronephric and mesonephric filtrate, forms the ureteric bud of the metanephros and gives rise to the ductus deferens of the testis. in addition, the pnd and ureteric bud epithelia induce terminal differentiation of the mesonephric and metanephric mesenchyme, respectively. elongation of the pnd in all vertebrates involves active cell migr ... | 1996 | 8877443 |
| lens induction in axolotls: comparison with inductive signaling mechanisms in xenopus laevis. | amphibian lens induction is an embryonic process whose broad outlines are conserved between anurans and urodeles; however, it has been argued that some aspects of this process differ significantly between even closely related species. classical embryologists concluded that in some species direct contact between the optic vesicle and ectoderm was both necessary and sufficient to induce the ectoderm to form a lens, while in other species tissues other than the optic vesicle induce lens formation. ... | 1996 | 8877449 |
| molecular mechanisms in the control of limb regeneration: the role of homeobox genes. | axolotls are unique among vertebrates in their ability to regenerate lost appendages as adults. they provide the opportunity to study the mechanism of regeneration in vertebrates and are an inspiration to pursue the goal of appendage regeneration in humans. in this article, we review data on the role of homeobox-containing genes in the regulation of limb regeneration. as a group, these genes are important in pattern formation in the primary body axis, developing limbs and regenerating limbs. to ... | 1996 | 8877453 |
| what insights into the developmental traits of urodeles does the study of interspecific hybrids provide? | natural and artificial hybrids represent an important source of material for developmental and evolutionary studies of urodeles. we review the available literature on hybrid salamanders, emphasizing the unique developmental insights that these organisms provide. of particular interest is the application of new molecular tools to identify dna markers for traditional characters in developmental research, and we discuss our own results using bulk segregant analysis to identify rapd markers for the ... | 1996 | 8877462 |
| axolotls in the second grade. | 1996 | 8877463 | |
| urodele (e.g., axolotl) embryos in the undergraduate laboratory class: an essay describing a multifaceted learning experience. | 1996 | 8877465 | |
| a method for the isolation and culture of embryonic cardiomyocytes from mexican axolotl. | 1996 | 8877466 | |
| treatment of axolotls with retinoids for limb regeneration studies. | 1996 | 8877467 | |
| how to observe surface contraction waves on axolotl embryos. | 1996 | 8877469 | |
| activation by mitogens and superantigens of axolotl lymphocytes: functional characterization and ontogenic study. | urodele amphibians have weak and slow immune responses compared to mammals and anuran amphibians. using new culture conditions, we tested the ability of lymphocytes of a well-studied salamander, the mexican axolotl (ambystoma mexicanum) to proliferate in vitro with diverse mitogenic agents. we demonstrated that the axolotl has a population of b lymphocytes that proliferate specifically and with a high stimulation index to the lipopolysaccharide (lps) known as a b-cell mitogen in mammals. this pr ... | 1996 | 8881761 |
| 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 |
| influence of insulin-like growth factors and insulin on the [35s]sulfate uptake by cartilage of the axolotl (ambystoma mexicanum). | the actions of mammalian insulin-like growth factors (igf-i and igf-ii) and insulin on skeletal growth of the axolotl, ambystoma mexicanum, were examined by monitoring the in vitro uptake of [35s]sulfate by cartilage. both growth factors stimulated sulfate uptake significantly at a concentration of 13 nm. the increase after incubation with 130 nm insulin was similar (uptake ca. 160% of control), but the effect was not significant. further, the binding of 125i-igf-i and 125i-igf-ii was studied in ... | 1996 | 8921360 |
| expression of myosin heavy chain transcripts in normal and cardiac mutant mexican axolotls. | in this study, we have cloned a 1.0 kb myosin heavy chain (mhc) cdna by screening an axolotl heart cdna library with the monoclonal antibody mf20 against a light meromyosin (lmm) region of mhc. the nucleotide sequence analysis shows 85-86% homology at the amino acid and 78-81% homology at the nucleic acid level with mhc from other vertebrates. phylogenetic analyses suggest that axolotl beta-mhc forms a cluster with the myosin ii group of vertebrate striated muscles. within the myosin ii cluster, ... | 1996 | 8932525 |
| nerve dependency of regeneration: the role of distal-less and fgf signaling in amphibian limb regeneration. | dlx-3, a homolog of drosophila dll, has been isolated from an axolotl blastema cdna library, and its expression in developing and regenerating limbs characterized. the normal expression pattern, and the changes that occur during experimental treatments, indicate a correlation between dlx-3 expression and the establishment of the outgrowth-permitting epidermis. dlx-3 is expressed at high levels in a distal-to-proximal gradient in the epidermis of developing limb buds, and is upregulated in the ap ... | 1996 | 8951064 |
| a specific synthetic rna promotes cardiac myofibrillogenesis in the mexican axolotl. | ambystoma mexicanum is an intriguing animal model for studying heart development because it carries a mutation in gene c. hearts of homozygous recessive (c/c) mutant embryos do not contain organized myofibrils and fail to beat. however, the defect can be corrected by organ-culturing the mutant heart in the presence of rna from anterior endoderm or rna from endoderm mesoderm-conditioned medium. we constructed a cdna library from total conditioned medium rna in a pcdnaii expression vector. we scre ... | 1996 | 8955002 |
| effects of the antiepileptic drug valproic acid on the development of the axolotl (ambystoma mexicanum): histological investigations. | in the amphibian ambystoma mexicanum, valproic acid (vpa) causes retarded development and malformations including neural tube defects. some of the observed abnormalities resemble exencephaly. we present the light microscopic characteristics of vpa-induced effects on the developing central nervous system (cns) as well as on other developing tissues of this species. to induce malformations, various concentrations of vpa were applied to embryos from blastula stage on, either as 24-h pulse or as con ... | 1996 | 8983118 |
| structure and diversity of the t-cell receptor alpha chain in the mexican axolotl. | polymerase chain reaction was used to isolate cdna clones encoding putative t-cell receptor (tcr) alpha chains in an amphibian, the mexican axolotl (ambystoma mexicanum). five tcralpha-v chain-encoding segments were identified, each belonging to a separate family. the best identity scores for these axolotl tcralpha-v segments were all provided by sequences belonging to the human tcralpha-v1 family and the mouse tcralpha-v3 and tcralpha-v8 families. a total of 14 different tcra-j segments were id ... | 1997 | 9002443 |
| pg-m/versican-like proteoglycans are components of large disulfide-stabilized complexes in the axolotl embryo. | large disulfide-stabilized proteoglycan complexes were previously shown to be synthesized by the epidermis of axolotl embryos during stages crucial to subepidermal migration of neural crest cells. we now show that the complexes contain pg-m/versican-like monomers in addition to some other component with low buoyant density. metabolically 35s-labeled proteoglycans were extracted from epidermal explants and separated by size exclusion chromatography and density equilibrium gradient centrifugation. ... | 1997 | 9013561 |
| cardioventilatory responses to hypoxia and nacn in the neotenous axolotl. | ventilatory and cardiac responses to hypoxia, sodium cyanide (nacn), and intra-arterial injection of atropine, noradrenaline and dl-propranolol were investigated in the neotenous axolotl (ambystoma mexicanum). hypoxia elicited increased gill and lung ventilation and a tachycardia. gill ventilation and air-breathing were stimulated by nacn infused either into the ventilatory water stream or into the bloodstream. cardiac responses to nacn were complex, with an initial bradycardia followed by a tac ... | 1996 | 9017844 |
| regulation of intracellular ph in salamander retinal rods. | 1. we measured intracellular ph (phi) in rods isolated from the retina of the axolotl salamander, ambystoma mexicanum, using the fluorescent indicator 2',7'-bis(carboxyethyl)-5(and -6)-carboxyfluorescein (bcecf). 2. the light exposures associated with data acquisition had no marked effect on phi. there was no sharp change between the value obtained from the first exposure of dark-adapted rods and subsequent readings. increasing the acquisition frequency from 1 to 10 min-1 either had no effect, o ... | 1997 | 9023768 |
| isolation of mhc class i cdnas from the axolotl ambystoma mexicanum. | class i major histocompatibility complex (mhc) cdna clones were isolated from axolotl mrna by polymerase chain reaction (pcr) and by screening a cdna phage library. the nucleotide and predicted amino acid sequences show definite similarities to the mhc class ialpha molecules of higher vertebrates. most of the amino acids in the peptide binding region that dock peptides at their n and c termini in mammals are conserved. several amino acids considered to be important for the interaction of beta2-m ... | 1997 | 9038100 |
| analysis of the three-dimensional distributions of alpha-actinin, ankyrin, and filamin in developing hearts of normal and cardiac mutant axolotls (ambystoma mexicanum). | alpha-actinin is an actin binding protein that assists in the stabilization of the plasma membrane and helps to fix organelles in position in a variety of cell types. in muscle, it is a major component of the z-lines of organized myofibrils. ankyrin binds to various elements of the cytoskeletal system including microtubules, microfilaments, and intermediate filaments and may help to anchor these structures to the cell membrane. filamin is a well-characterized actin-associated protein first isola ... | 1997 | 9045985 |
| differential expression of a novel isoform of alpha-tropomyosin in cardiac and skeletal muscle of the mexican axolotl (ambystoma mexicanum). | alternative mrna splicing is a fundamental process in eukaryotes that contributes to tissue-specific and developmentally regulated patterns of tropomyosin (tm) gene expression. northern blot analyses suggest the presence of multiple transcripts of tropomyosin in skeletal and cardiac muscle of adult mexican axolotls. we have cloned and sequenced two tropomyosin cdnas designated atmc-1 and atmc-2 from axolotl heart tissue and one tm cdna from skeletal muscle, designated atms-1. nucleotide sequence ... | 1997 | 9055812 |
| evidence for the presence and participation of 85-75 kda extracellular matrix components in cell interactions of bufo arenarum gastrulation. | we studied the presence and distribution of the extracellular materials (ecm), obtained by mild embryonic dissociation through nondenaturing and denaturing page, immunoblotting and immunocytochemical wholemount in the gastrulation of anuran amphibian bufo arenarum. the sds-page, under reducing conditions, revealed the protein profile of the ecm which comprised six bands. the western immunoblotting effected with antibodies against fibronectins (fn) of xenopus laevis, ambystoma mexicanum and bufo ... | 1997 | 9062995 |
| hypochord, an enigmatic embryonic structure: study of the axolotl embryo. | the hypochord of the axolotl embryo is first visible at an early tailbud stage, forming a rod-like structure, situated immediately under the notochord. a profusion of extracellular matrix fibrils is attached to the dorsolateral regions of the hypochord, linking it with the somites. a basal lamina develops around the hypochord, indicating an epithelial type of cell differentiation. abundant rough endoplasmic reticula in the hypochord cells suggest lively synthetic activity. prospective endoderm c ... | 1997 | 9068201 |