Publications

polymorphism of hyaluronidase in serum from man, various mouse strains and other vertebrate species revealed by electrophoresis.	polymorphism of hyaluronidase (ec 3.2.1.35) was detected in the serum from 6 out of 20 vertebrate species by electrophoretic analysis. electrophoresis was performed on a hyaluronan-containing polyacrylamide gel, that visualizes hyaluronidase activity upon incubation at acid ph. no hyaluronidase activity was detected in the sera of horse, swine, cattle, goat, sheep, rabbit, chicken, triton alpestris, triton palmatus, triton vulgaris, pleurodeles, axolotl, eel and dog-fish. the 6 positive sera wer ...	1990	2357493
development and application of homologous radioimmunoassay for newt prolactin.	a specific and sensitive homologous radioimmunoassay (ria) for newt (cynops pyrrhogaster) prolactin (prl) was developed. prl isolated from newt pituitary glands was used for generating antiserum in a rabbit, for radioiodination, and for the standard. several dilutions of plasma and pituitary homogenate of newts yielded dose-response curves which were parallel to the standard curve. plasma from hypophysectomized newts showed the least amount of cross-reaction. pituitary homogenates of other speci ...	1990	2354781
isolation and characterization of the third complement component of axolotl (ambystoma mexicanum).	1. using a monoclonal anti-human c3 antibody and a polyclonal anti-cobra venom factor antibody as probes, a protein homologous to the mammalian third complement component (c3) was purified from axolotl plasma and found to be axolotl c3. 2. axolotl c3 consists of two polypeptide chains (mr = 110,000 and 73,000) linked by disulfide bonds. an internal thiolester bond in the alpha chain was identified by the incorporation of [14c]methylamine and nh2-terminal sequence from the c3d fragment of c3. 3. ...	1990	2344737
comparative studies on the vascular organization of carotid labyrinths of anurans and caudates.	the three-dimensional structures of the carotid labyrinth in five species of anurans representing four families (rana nigromaculata, rana catesbeiana, bufo japonicus, hyla arborea, and xenopus laevis), and three species of caudates representing three families (cynops pyrrhogaster, hynobius nebulosus, ambystoma mexicanum) were compared using vascular corrosion castings and scanning electron microscopy (sem). anuran carotid labyrinths are spherical in shape and are classified into two groups accor ...	1990	2338718
developmentally regulated lectin in dark versus white axolotl embryos.	the white mutant of the mexican axolotl, a. mexicanum, involves an ectodermal defect which prevents melanophore colonization. endogenous lectins have been suggested to function in neural crest-derived melanophore adhesion in other animals. to determine if differences in endogenous lectins exist in dark and white axolotls during melanophore colonization, white and dark ectoderm and carcass tissues have been assayed for lectin activity at premigratory, early migratory, and late migratory neural cr ...	1990	2302235
epicardial development in the axolotl, ambystoma mexicanum.	recent studies on avian and mammalian embryos have established that the epicardium is derived, not from the early heart tube, but from mesothelial tissue overlying the sinus venosus. we tested the validity of this concept for amphibia by examining normal and cardiac lethal (c/c) mutant axolotl embryos (stages 35-43) by electron microscopy. in axolotl embryos, the myocardial surface of the heart remains exposed to the pericardial fluid through stage 39. at this stage the transverse septum release ...	1990	2301739
characterization of the yellow pigment in the axanthic mutant of the mexican axolotl, ambystoma mexicanum.	the yellow pigment observed in older axanthic (ax/ax) mutant mexican axolotls (ambystoma mexicanum) was analyzed by thin layer chromatography and by spectrofluorometry of its acetyl derivative. ethanol extracts from the skin of axanthic animals were acetylated and the chloroform-soluble portion of the product mixture was compared with a chloroform solution of an authentic riboflavin tetraacetate standard prepared in the same manner. the pigment in these two solutions behaved identically on thin ...	1990	2290784
effects of tributyltin oxide on the skeletal structures of developing and regenerating limbs of the axolotl larvae, ambystoma mexicanum.		1990	2279120
nucleotide sequence of a cdna encoding wnt-1 of the mexican axolotl ambystoma mexicanum.		1990	2259633
development of the mechanoreceptive lateral-line system in the axolotl: placode specification, guidance of migration, and the origin of neuromast polarity.	the mechanosensory lateral-line system offers a unique opportunity to study a wide variety of developmental phenomena, including cell migration, the origin of polarity, and pattern formation. in this study, we use a series of transplantation experiments to examine some of the factors affecting the origin of the lateral-line placodes, the establishment of sensory organ polarity and placement, and the guidance of cell migration in the mexican axolotl (ambystoma mexicanum). we find that placode-for ...	1990	2244689
[v. laufberger on metamorphosis in the axolotl].		1990	2225132
[metamorphosis today].	in conjunction with the 100th anniversary of birth of the czech physiologist v. laufberger who discovered in 1913 the possibility to induce metamorphosis in neotenous larvae of axolotls by feeding them with thyroid gland, the author gives an account on the development of knowledge regarding metamorphosis in amphibia. he analyzes the participation of endocrine glands, in particular thyroid hormones and prolactin. special attention is devoted to mechanisms leading to resorption of the tail in tadp ...	1990	2224961
the origins of neural crest cells in the axolotl.	we address the question of whether neural crest cells originate from the neural plate, from the epidermis, or from both of these tissues. our past studies revealed that a neural fold and neural crest cells could arise at any boundary created between epidermis and neural plate. to examine further the formation of neural crest cells at newly created boundaries in embryos of a urodele (ambystoma mexicanum), we replace a portion of the neural folds of an albino host with either epidermis or neural p ...	1990	2210034
the mhc molecules of nonmammalian vertebrates.	there is very little known about the long-term evolution of the mhc and mhc-like molecules. this is because both the theory (the evolutionary questions and models) and the practice (the animals systems, functional assays and reagents to identify and characterize these molecules) have been difficult to develop. there is no molecular evidence yet to decide whether vertebrate immune systems (and particularly the mhc molecules) are evolutionarily related to invertebrate allorecognition systems, and ...	1990	2180813
eliminating afferent impulse activity does not alter the dendritic branching of the amphibian mauthner cell.	in the developing amphibian, the formation of extra vestibular contacts on the mauthner cell (m-cell) enhances dendritic branching, while deprivation reduces it (goodman and model, 1988a). the mechanism underlying the interaction between afferent fibers and developing dendritic branches is not known; neural activity may be an essential component of the stimulating effect. we examined the role of afferent impulse activity in the regulation of m-cell dendritic branching in the axolotl (ambystoma m ...	1990	2155302
selective labeling of sensory hair cells and neurons in auditory, vestibular, and lateral line systems by a monoclonal antibody.	this study reports that zn-1, a monoclonal antibody, labels hair cells but not supporting cells in the inner ear and the lateral line of the axolotl salamander, ambystoma mexicanum. zn-1 immunocytochemically labels the cytoplasm and stereocilia of mature hair cells in the sacculus, in the utriculus, and in the mechanoreceptive neuromast organs of the lateral line. lower levels of labeling mark newly formed hair cells in the periphery of the sacculus and in regenerating neuromasts. zn-1 also sele ...	1990	2124588
structural and compositional divergencies in the extracellular matrix encountered by neural crest cells in the white mutant axolotl embryo.	the skin of the white mutant axolotl larva is pigmented differently from that of the normal dark due to a local inability of the extracellular matrix (ecm) to support subepidermal migration of neural crest-derived pigment cell precursors. in the present study, we have compared the ecm of neural crest migratory pathways of normal dark and white mutant embryos ultrastructurally, immunohistochemically and biochemically to disclose differences in their structure/composition that could be responsible ...	1990	2119290
high levels of hmg1-2 protein expression in the cytoplasm and nucleus of hydrocortisone sensitive amphibian thymocytes.	a major 26 kda protein was identified in the cytoplasmic and nuclear compartments of axolotl thymocytes. a polyclonal antiserum was produced against the denatured form of this protein. high levels of 26 kda were expressed by hydrocortisone-sensitive lymphocytes which represent a major thymocyte subpopulation in young animals. however, no further expression of the 26 kda protein was observed in involuted thymus of adult animals nor in thymus of young artificially metamorphosed axolotls. the 26 kd ...	1990	2097001
effects of fetal bovine serum and serum-free conditions on white and dark axolotl neural crest explants.	neural crest cells from both white mutant and dark (wildtype) axolotls (ambystoma mexicanum) were cultured in increasing concentrations of fetal bovine serum (fbs; 2 to 20%). for each explant, the total number of cells that migrated and the percent of differentiated melanophores were recorded. at concentrations of fbs above 2% melanophore differentiation was essentially equivalent (32 to 59%) for both the white and dark neural crest cultures, but subtle differences in cell behavior and different ...	1991	2071543
localization of smooth-muscle markers in the ovaries of some ectothermic vertebrates.	in the present study, we have localized desmin and alpha-smooth-muscle actin in the ovaries of the zebrafish, the axolotl, and the red-eared turtle, using the unlabelled antibody peroxidase-antiperoxidase technique. in the axolotl ovary both smooth-muscle markers were demonstrated in cord-like structures, extended along ovarian blood vessels, and in some inner ovarian epithelium cells. in the ovaries of the teleost, smooth-muscle-like cells are detected in a suspensory apparatus formed by venous ...	1991	2048748
acidic fibroblast growth factor is present in regenerating limb blastemas of axolotls and binds specifically to blastema tissues.	the growth of regenerating limbs of amphibians depends upon proliferation of the blastema cells that accumulate beneath the epidermal cap. the epidermal cap is known to be mitogenic for the blastema cells. we have extracted a mitogenic activity from both the mesenchymal and epidermal (epidermal cap) components of cone stage blastemas which is retained on heparin-sepharose and elutes with 1.15 m nacl. this fraction stimulates neurite outgrowth of pc12 cells and [3h]thymidine incorporation into cc ...	1991	2040374
sequence, organization and transcriptional analysis of a gene encoding a u1 snrna from the axolotl, ambystoma mexicanum.	amu1, a dna fragment containing a u1 small nuclear rna (snrna)-encoding gene, was isolated from the axolotl, ambystoma mexicanum. although this u1 snrna, produced in axolotl oocytes, exhibits the lowest degree of sequence conservation among vertebrates, its secondary structure is maintained by a number of compensatory base changes. the proximal sequence element (pse) is only weakly similar to that of the previously characterized xenopus laevis pse. exchanging either the entire upstream regions w ...	1991	2022330
nucleotide sequence of a cdna encoding wnt-1 of the mexican axolotl ambystoma mexicanum.		1991	2017393
dna ligase i from xenopus laevis eggs.	we have purified the major dna ligase from xenopus laevis eggs and raised antibodies against it. estimates from sds page indicate that this dna ligase is a 180 kda protein. this enzyme is similar to the mammalian type i dna ligase which is presumed to be involved in dna replication. we have also analysed dna ligase activity during x. laevis early development. unfertilized eggs contain the highest level of activity reflecting the requirement for a large amount of dna replicative enzymes for the p ...	1991	2017356
organization of motor units in the axolotl: a continuously growing animal.	the characteristics of motor units in the iliotibialis posterior muscle of the axolotl hindlimb are described. tension recording and intracellular electrophysiological methods demonstrate that the physiological properties of the population of motor units are continuously distributed rather than grouped into a series of discrete types. overlap between motor units occurs and this is positively correlated with motor unit size but negatively correlated with differences in time to peak tension. immun ...	1991	2013646
continuous growth of the motor system in the axolotl.	during growth of the axolotl, motor neurons, and muscle fibres are added to the motor system. by double labelling neurons with tritiated thymidine and retrogradely transported hrp, we show that some motor neurons are born at postembryonic stages. further analysis of motor neurons with the aid of hrp reveals this population of newly born cells relatively frequently in small (5-7 cm long) axolotls, but only rarely in large (7-13 cm long) axolotls. evidence is presented that suggests that these imm ...	1991	2013645
expression of the 9g1 antigen in the apical cap of axolotl regenerates requires nerves and mesenchyme.	monoclonal antibody 9g1 (mab 9g1) is reactive to the wound epithelium of axolotl larvae and therefore provided the opportunity to examine the interaction between the wound epithelium, nerves, and blastemal mesenchyme during axolotl limb regeneration. in unamputated limbs, mab 9g1 is reactive to most or all cells of the dermis, skeletal elements, blood vessels, and nerves, to a few unidentified cells in muscle, and to none in epidermis. during regeneration of axolotl limbs, mab 9g1 reacts strongl ...	1991	2005423
identification of kainic and quisqualic acid receptors on inner retinal cells of the salamander ambystoma mexicanum.	the presence of kainic (ka) and quisqualic acid (qa) receptors on inner retinal neurones of the axolotl ambystoma mexicanum has been studied using intracellular recording techniques. in the presence of cocl2, which blocks neurotransmitter release, ka and qa depolarized the membrane. the minimum concentration of ka that induced a response was 1 microm and a maximum response was obtained with 10 microm (ec50: 3 microm). the operating range of qa was between 0.5 and 5 microm with an ec50 of 1 micro ...	1990	1976525
heart development in normal and cardiac-lethal mutant axolotls: a model for the control of vertebrate cardiogenesis.	the mechanisms which regulate myocardial differentiation are poorly understood. the cardiac-lethal (c) mutant of ambystoma mexicanum, in which the heart never begins to beat, provides a valuable model system for studying this process. using an in vitro assay, we examine the nature of the defect in c/c embryos and find (contrary to previous reports) that the inductive endoderm is not affected by the mutation. rather, the pre-cardiac mesoderm is directly affected by the c gene and is incapable of ...	1991	1959711
well-defined growth factors promote cardiac development in axolotl mesodermal explants.	the effect of growth factors on the formation of cardiac mesoderm in the urodele, ambystoma mexicanum (axolotl), has been examined using an in vitro explant system. it has previously been shown that cardiac mesoderm is induced by pharyngeal endoderm during neurula stages in urodeles. in this study, explants of prospective cardiac mesoderm from early neurula stage embryos rarely formed beating cardiac tissue in culture. when transforming growth factor beta-1 (tgf-beta 1) or platelet-derived growt ...	1991	1935698
large disulfide-stabilized proteoglycan complexes are synthesized by the epidermis of axolotl embryos.	proteoglycans (pgs) synthesized by the epidermis during stages crucial to the subepidermal migration of neural crest cells in the trunk of the axolotl (ambystoma mexicanum, urodela, amphibia) embryo were studied. the glycosaminoglycan chains were biosynthetically labeled with [35s]sulfate in vitro during a period corresponding to the onset of migration. after extraction with guanidine hcl, the radiolabeled pgs were separated according to size by molecular-sieve chromatography on sepharose cl-2b ...	1991	1929407
axonal transport and release of transferrin in nerves of regenerating amphibian limbs.	transferrin, a plasma protein required for proliferation of normal and malignant cells, is abundant in peripheral nerves of birds and mammals and becomes more concentrated in this tissue during nerve regeneration. we are testing the hypothesis that this factor is involved in the growth-promoting effect of nerves during the early, avascular phase of amphibian limb regeneration. a sensitive enzyme-linked immunosorbent assay for axolotl transferrin was developed and used to determine whether this p ...	1991	1916015
retinoic acid does not induce formation of cilia on the surface of wound epithelial cells in axolotls.	it has been reported that vitamin a palmitate induces the production of cilia on the epidermal cells of the regenerating axolotl limb, and the formation of crevices in the epidermal surface. the aim of the present investigation was to reexamine under well defined conditions the potential of retinoids to evoke the above described metaplastic changes. in order to achieve our purpose we administered axolotls with retinoic acid for 2, 4, 6, 8, and 10 days after limb amputation. the young regenerates ...	1991	1913848
radial glia give rise to perinodal processes.	nodes of ranvier in the central nervous system in mammals are characterized by the presence of perinodal astrocytic processes. this study examines the association between processes of radial glia and the axolemma at nodes of ranvier in the spinal cord of the mature axolotl, an animal in which radial glia represent a large portion of the total glial population. the radial glial cells have their cell bodies located close to the central canal. those situated dorsal to the canal send long processes ...	1991	1893250
reinvestigation of dna ligase i in axolotl and pleurodeles development.	we have recently shown that the exclusion process causing the replacement of dna ligases ii by dna ligase i in amphibian eggs after fertilization does not occur in the case of xenopus laevis [hardy, s., aoufouchi, s., thiebaud, p., and prigent, c., (1991) nucleic acids res. 19, 701-705]. since this result is in contradiction with the situation reported in axolotl and pleurodeles we decided to reinvestigate such results in both species. three different approaches have been used: (1) the substrate ...	1991	1886765
extracellular matrix of the developing heart in normal and cardiac lethal mutant axolotls, ambystoma mexicanum.	as part of an ongoing study of heart development in normal and cardiac lethal mutant axolotls (mexican salamanders) we examined the extracellular matrix (ecm) by microscopical methods. with scanning electron microscopy we are unable to detect ecm on the apical surface of cells of the early cardiogenic mesoderm. during the period of lateral plate migration, which coincides with the period of cardiogenic induction of mesoderm by anterior endoderm, there is little ecm, aside from some microfibrils, ...	1991	1867413
retinoic acid stimulates neurite outgrowth in the amphibian spinal cord.	there is increasing evidence that retinoic acid (ra), a vitamin a metabolite, plays a role in the development of the nervous system. here we specifically test this notion by examining the effect of ra on neurite outgrowth from explanted segments of the axolotl spinal cord. we show that there is a threshold concentration in the region of 0.1-1 nm above which neurite outgrowth is stimulated 4-5 fold. retinol, by contrast, only stimulated the migration of glial cells from the explants. using hplc w ...	1991	1850835
measures of phototaxis and movement detection in the larval salamander.	in this investigation, we describe two precise tests of visual function that integrate quasinatural situations with time-lapse video recording and infrared computerized monitoring of activity to assess movement detection and phototaxic tendencies, respectively. four groups of larvae from a. punctatum, a. tigrinum, a. mexicanum, and a mutant albino axolotl were tested in an alley containing light and dark halves and lined with infrared sensors to monitor their phototaxic response. a. punctatum sh ...	1991	1801024
the glossopharyngeal nerve of the axolotl labeled with carbocyanine dye (dii).	fluorescent carbocyanine dye (dii) was used to label the glossopharyngeal (ix) nerve in the fixed preparation of the mexican salamander, axolotl. when the cell bodies were viewed with a confocal laser scanning microscope and nomarski optics, the cytoplasm was brightly fluorescent, but not the cell nucleus. the cell bodies which send peripheral axons in the two branches of the ix nerve were mainly distributed in the rostral part of the combined glossopharyngeal-vagus ganglion, but a few cells wer ...	1989	1791970
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
effect of precocious and delayed afferent arrival on synapse localization on the amphibian mauthner cell.	afferents often form synapses on restricted regions of their target cells. the connections between vestibular axons and the mauthner cell are an example of this sort of specificity. the mauthner cells are a pair of identifiable central neurons in certain fish and amphibians. in the axolotl (ambystoma mexicanum), the large vestibular axons form club endings on only one portion of one dendrite of the mauthner cell. during development, this specific distribution might result from nothing more than ...	1991	1761755
a light and electron microscopic study of the development of the mauthner cell and vestibular nerve in the axolotl.	vestibular axons form synapses on a restricted area of the lateral dendrite of the mauthner cell, a large, identified brainstem neuron found in fish and amphibians. the differentiation of the vestibular nerve, medullary neuropil, and mauthner cell of the axolotl (ambystoma mexicanum) was studied to understand better the means by which this synaptic specificity arises. the mauthner cell first extends a medial process and then a lateral dendrite. the latter initially elongates as a simple process ...	1991	1761753
[adaptative differential maturation of neurohypophyseal provasotocin in amphibians: presence of hydrin 2(vasotocinyl-glycine) in anura but not in urodela].	occurrence of hydrin 2 (vasotocinyl-glycine), an intermediate in the provasotocin processing, has been shown in the neurointermediate lobe of the pituitary of semi-aquatic or terrestrial amphibian species belonging to the order anura, namely rana esculenta, r. temporaria, r. pipiens (ranidae), and bufo bufo, b. marinus, b. ictericus (bufonidae). in contrast hydrin 2 appears absent in species belonging to the order urodela, namely the axolotl ambystoma mexicanum (ambystomidae) and the pleurodele ...	1991	1756409
the differential transcriptional activity of two amphibian u1 small-nuclear rna genes correlates with structural differences in the proximal sequence element.	we previously analyzed the transcription of an axolotl u1 small-nuclear rna (snrna) gene (amu1) by microinjection into xenopus laevis oocytes. in such an assay, amu1 showed a low template activity compared to that of an x. laevis u1 snrna gene (xlu1b2). swapping the proximal sequence element (pse) with that of xlu1b2 was required for amu1 to acquire a transcription level equal to that of xlu1b2. in the present work, we examine the functional importance of the nucleotides that are common or diffe ...	1992	1735429
hydrogen ion currents in rat alveolar epithelial cells.	alveolar epithelial cells isolated from rats and maintained in primary culture were studied using the whole-cell configuration of the "patch-clamp" technique. after other ionic conductances were eliminated by replacing permeant ions with n-methyl-d-glucamine methanesulfonate, large voltage-activated hydrogen-selective currents were observed. like h+ currents in snail neurons and axolotl oocytes, those in alveolar epithelium are activated by depolarization, deactivate upon repolarization, and are ...	1991	1722118
localization of calmodulin in epidermis and skin glands: a comparative immunohistological investigation in different vertebrate species.	the study deals with the immunolocalization of calmodulin-reactive epithelial cells in different vertebrates (tinca tinca, ambystoma mexicanum, xenopus laevis, rana ridibunda, columba domestica, sus scrofa domestica, homo sapiens sapiens). the immunoperoxidase technique was performed on acetone fixed frozen sections using monoclonal (bf8) and polyclonal (acam) anti-calmodulin antibodies. we were able to differentiate 2 major types of staining patterns: 1. a more superficial epidermal staining in ...	1991	1718122
heterogeneity in spinal radial glia demonstrated by intermediate filament expression and hrp labelling.	considerable evidence indicates that radial glial cells play an active role in guiding growing neurites during development of the vertebrate cns. in this paper we describe subpopulations of radial glial in the spinal cord of the axolotl. amphibians maintain radial glia throughout life, and subpopulations are described using anatomical criteria following filling of individual cells with horseradish peroxidase and immunocytochemical staining with a range of intermediate filament antibodies. radial ...	1990	1705577
morphology and distribution of the glossopharyngeal nerve afferent and efferent neurons in the mexican salamander, axolotl: a cobaltic-lysine study.	cobaltic-lysine complex was used to label the afferent and efferent components of the glossopharyngeal nerve in the ganglion and brainstem of the mexican salamander, axolotl (ambystoma mexicanum). the distribution of afferent cell bodies in the combined glossopharyngeal-vagus ganglion (the ix-x ganglion) was reconstructed from serial sections, and the sizes of the cell bodies were measured. the central projection of afferents and the location of efferent cell bodies were determined by the tracer ...	1990	1702112
alkaline phosphatase and dipeptidylpeptidase iv staining of tissue components of skeletal muscle: a comparative study.	a combined alkaline phosphatase (ap) and dipeptidlypeptidase iv (dpp iv) staining reaction has demonstrated enzymatic heterogeneity of the arterial and venous segments of capillaries in rat skeletal muscle. this study compared the staining reactions of skeletal muscles in many commonly used laboratory animals, including the axolotl, chick, quail, monodelphys, rat, mouse, hamster, guinea pig, rabbit, dog, monkey, and human. dpp iv activity was found in the venous ends of the capillaries and in th ...	1990	1701462
an extracellular matrix molecule of newt and axolotl regenerating limb blastemas and embryonic limb buds: immunological relationship of mt1 antigen with tenascin.	several well-characterized extracellular matrix (ecm) components have been localized to the amphibian limb regenerate, but the identification and characterization of novel ecm molecules have received little attention. here we describe, using mab mt1 and immunocytochemistry, an ecm molecule expressed during limb regeneration and limb development. in limb stumps, mab mt1 reactivity was restricted to tendons, myotendinous junctions, granules in the basal layers of epidermis, periosteum (newts) and ...	1990	1696876
isolation and characterization of a developmentally regulated homeobox sequence in the mexican axolotl ambystoma mexicanum.	a homeobox-containing genomic dna fragment was isolated from the mexican axolotl. this clone was obtained from a partial genomic library enriched for sequences that cross-hybridized with the drosophila antp homeobox under low stringency hybridization conditions. dna sequence analysis revealed that this sequence (ahox1) was 66% homologous to the antp homeobox sequence and was most closely related to the mouse hox-1.6 (84% identity) and drosophila lab (79% identity) homeobox sequences. several cro ...	1990	1695851
heart induction in wild-type and cardiac mutant axolotls (ambystoma mexicanum).	we have re-examined some of the factors affecting the induction of heart-forming mesoderm in the axolotl. the formation of functional, rhythmically contracting myocardial tissue was used as an assay. we have found that heart-forming mesoderm is fully induced and capable of completing its developmental repertoire by the end of neurulation. as has been previously reported, pharyngeal endoderm appears to be the major inductor of heart mesoderm. unlike previous workers, we have found that the induci ...	1990	1693393
mhc-like molecules in some nonmammalian vertebrates can be detected by some cross-reactive monoclonal antibodies.	mab to human and mouse mhc molecules were tested for binding to blood or spleen cells of various nonmammalian vertebrates by immunofluorescence and flow cytometry. those that bound were used to immunoprecipitate cross-reactive molecules from biosynthetically or cell surface-labeled spleen or blood cells. in addition, mab to human mhc molecules were screened by western blots. as expected from the results with xenoantisera, there were few mab that cross-reacted, and many of these cross-reactions w ...	1990	1690241
ectopic expression of a genomic fragment containing a homeobox causes neural defects in the axolotl.	an axolotl (ambystoma mexicanum) genomic fragment containing the ahox1 homeobox was placed under the control of the mouse hsp68 promoter, which seems to function constitutively in the axolotl. the resulting construct was injected into fertilized axolotl eggs to see if it would perturb development. of the injected embryos, 20% showed severe reduction of the anterior neural plate. later in development, these embryos had small heads, no eyes, and appeared to lack the normal regionalization of the b ...	1991	1680349
evidence for enkephalin- and endorphin-immunoreactive cells in the anterior pituitary of the axolotl ambystoma mexicanum.	an immunohistochemical study of opioid peptides in the hypophysis of the axolotl, ambystoma mexicanum, was carried out with antisera against leu-enkephalin, beta-endorphin, met-enkephalin, and dynorphin a (1-8). we found leu-enkephalin immunoreactivity in some fibers of the neural lobe and the median eminence. in contrast to previous reports on mammals and other vertebrates, we found leu-enkephalin immunoreactivity in many cells scattered throughout the anterior lobe. as in other vertebrates, th ...	1991	1674748
the respecification of limb pattern by new synthetic retinoids and their interaction with cellular retinoic acid-binding protein.	we describe here experiments to examine the role of cellular retinoic-acid-binding protein (crabp) during the induction of limb duplication in the chick limb bud and regenerating axolotl limb by retinoids. a newly synthesised class of retinoic acid analogues have been used because among them, some have been specifically designed with the property of binding to the retinoic acid receptors, but not to crabp. we can thus test whether binding to crabp is an obligatory step during limb respecificatio ...	1991	1655545
t-cell-specific membrane antigens in the mexican axolotl (urodele amphibian).	comparative analysis of sds-page patterns of axolotl spleen cells membrane detergent lysates showed important discrepancies between control and thymectomized animals. among these, a 38-kd protein band, which appeared as a major protein in controls, was not or poorly expressed after thymectomy. a rabbit antiserum (l12) raised against the 38-kd eluted band labeled in indirect immunofluorescence 80-86% of thymocytes and 40-46% of mig- lymphoid cells in the spleen. the anti-38-kd antibodies stained ...	1992	1627952
transient developmental expression of igy and secretory component like protein in the gut of the axolotl (ambystoma mexicanum).	we previously reported that a primitive vertebrate, the mexican axolotl (amphibian, urodela) synthesizes two classes of immunoglobulins. igm are present in serum early in the development, and represent the bulk of specific antibody synthesis after an antigenic challenge. igy occur in the serum later during the development, and are relatively insensitive to immunization. we demonstrate in the present work, using immunofluorescence with specific mabs, that igy are expressed in the gut epithelium, ...	1992	1627950
characterization of fibroblast growth factor binding in regenerating limb blastemas of axolotls.		1992	1614427
axonal release of transferrin in peripheral nerves of axolotls during regeneration.		1992	1614426
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
the mutant axolotl short toes exhibits impaired limb regeneration and abnormal basement membrane formation.	the mutant axolotl short toes develops with abnormal kidneys, mullerian ducts, and limbs and provides one of the few experimental systems for developmental studies in amphibia. the present paper describes another deviation from this animal's normal physiology, which is very characteristic of the wild type: amputated limbs of short toes fail to regenerate. a blastema is formed but differentiation does not occur. detailed histological analysis provides evidence of abnormal formation of the basemen ...	1992	1608961
retinoic acid-induced change in anteroposterior positional identity in regenerating axolotl limbs is dose-dependent.	retinoic acid (ra) induces pattern duplication in the proximodistal (pd) axis of axolotl limb regenerates. the effect is dose-dependent, with the maximum extent of duplication being evoked at a dose of 150 micrograms ra/g body weight. the same dose of ra induces maximum pattern completion in the anteroposterior (ap) axis of regenerating anterior half or double anterior half limbs. ra inhibits the regeneration of posterior half or double posterior half limbs (kim, w.s., and stocum, d.l. [1986] de ...	1992	1600247
the stopping response of xenopus laevis embryos: behaviour, development and physiology.	1. when xenopus laevis embryos swim into an obstruction they usually stop. this stopping response to stimulation on the head is present from stage 28 to 45. at stage 37/38 it is more reliable in restrained than in free-swimming animals, and to stimuli to the cement gland than to the head skin. 'fictive' swimming also stops reliably after the same stimuli but struggling and 'fictive' struggling do not. 2. discharge of deformation-sensitive trigeminal sensory neurons in response to pressure on the ...	1992	1583603
ganglia implantation as a means of supplying neurotrophic stimulation to the newt regeneration blastema: cell-cycle effects in innervated and denervated limbs.	regulation of blastema cell proliferation during amphibian limb regeneration is poorly understood. one unexplained phenomenon is the relatively low level of active cell cycling in the adult newt blastema compared to that of larval axolotls. in the present study, we used ganglia implantation as a means of "superinnervating" normally innervated adult newt blastemas to test whether blastema cell subpopulations are responsive to nerve augmentation. the effectiveness of implanted ganglia to provide n ...	1992	1583454
the marginal zone of the 32-cell amphibian embryo contains all the information required for chordamesoderm development.	the formation of the amphibian organizer is evidenced by the ability of cells of the dorsal marginal zone (dmz) to self-differentiate to form notochord and to induce the formation of other axial structures from neighboring regions of the embryo. we have attempted to determine when these abilities are acquired in the urodele, ambystoma mexicanum (axolotl), and in the anuran, xenopus laevis, by removing the mesodermalizing influence of the vegetal hemisphere at different stages of development and ...	1992	1583451
effects of tunicamycin on retinoic acid induced respecification of positional values in regenerating limbs of the larval axolotl, ambystoma mexicanum.	urodele amphibians possess a remarkable ability to regenerate limbs following experimental or accidental amputation. since only those parts of the limb distal to the plane of amputation usually regenerate, this suggests the existence of level-specific positional values within the cells of the limb. vitamin a and other retinoids respecify the positional values of regenerating limbs such that structures proximal to the actual plane of amputation are formed in the regenerating limb producing proxim ...	1992	1581606
inhibition of neural crest cell differentiation by embryo ectodermal extract.	the white mutation in mexican axolotls has long been thought to be a defect associated with the embryonic extracellular environment, but not with embryonic neural crest cells. thus it was believed that pigment cells in white axolotls disappear from the skin during early development, not because they are intrinsically defective but because they have no choice but to move into an unfavorable environment. we present evidence to suggest that: (1) white neural crest cells are in fact intrinsically di ...	1992	1569410
thyroid hormone receptors and iodothyronine deiodinases in the developing mexican axolotl, ambystoma mexicanum.	the mexican axolotl, ambystoma mexicanum, is a neotenous salamander that rarely undergoes anatomical metamorphosis, but can be induced to do so by administration of thyroxine (t4). the neoteny appears to be due primarily to low levels of plasma t4 secondary to a low rate of secretion of thyroid-stimulating hormone. however, other factors may also be involved. in anuran amphibia, metamorphosis is accompanied by alterations in thyroid hormone receptor concentration and marked changes in the activi ...	1992	1563619
phylogeny of the third component of complement, c3: analysis of the conservation of human cr1, cr2, h, and b binding sites, concanavalin a binding sites, and thiolester bond in the c3 from different species.	the third component of complement, c3, binds to several other complement proteins. to study the diverse reactivities of c3, we analyzed the conservation of structural and functional features in the c3 from different species. first, we developed a method to purify swine (po), rabbit (rb), mouse (mo), cobra (co), xenopus (xe), axolotl (ax), and trout (tr) c3 from plasma. this involved protein precipitation by polyethylene glycol, followed by anion-exchange, gel filtration, and cation exchange chro ...	1992	1535601
histological analysis of forelimb regeneration in the california newt taricha granulosa.	the regenerative ability of the forelimbs of the california rough-skinned newt, taricha granulosa was determined and compared to the same ability of the adult mexican axolotl, ambystoma mexicanum. forelimbs were amputated distally at the wrist and limbs removed at 1, 2, 3, 4, 5 and 6 weeks post-amputation were examined by histological analysis. since vitamin a and its derivatives cause extreme changes in pattern formation in the regenerating amphibian limb, we decided to study the ability of ret ...	2005	1525332
primary structure of neutral and acidic oligosaccharide-alditols derived from the jelly coat of the mexican axolotl. occurrence of oligosaccharides with fucosyl(alpha 1-3)fucosyl(alpha 1-4)-3-deoxy-d-glycero-d-galacto-nonulosonic acid and galactosyl(alpha 1-4)[fucosyl(alpha 1-2)]galactosyl(beta 1-4)-n-acetylglucosamine sequences.	six major neutral and acidic oligosaccharide-alditols were prepared from the jelly coat of mexican axolotl eggs. these compounds were demonstrated to contain 3-deoxy-d-glycero-d-galacto-nonulosonic acid (dnloa) and l-fucose (fuc). the structures of the six major oligosaccharides were established as follows: [sequence: see text]	1992	1499572
distribution and innervation of lateral line organs in the axolotl.	the lateral line system in axolotls consists of three types of receptors and the cranial nerves that innervate them. superficial neuromasts, which are mechanoreceptors, are distributed in lines on both the head and trunk. eight cephalic and three trunk lines can be distinguished on the basis of their innervation and differences in the orientation of the major axes of their neuromasts. a combination of histological techniques reveals that five separate pairs of cranial nerves innervate the neurom ...	1992	1484121
structural and endocytotic differences of fibroblasts and macrophages in the tail fin of amphibian larvae during metamorphosis.	different features in the fibroblasts and the macrophages, which are prominent cell types in the dermis of the dorsal tail fin of the larval axolotl, ambystoma mexicanum, and the tadpole, rana japonica, were examined by light and electron microscopy. at the non-metamorphic stages, the cytoplasm of the macrophage, loaded with numerous lysosomes, is generally located in the cell periphery. outstanding was the presence of many ruffles or microvillous projections of different shapes and sizes in the ...	1992	1482609
reproducible proliferative responses of salamander (ambystoma mexicanum) lymphocytes cultured with mitogens in serum-free medium.	there are several reports that proliferative responses (tritiated thymidine incorporation (3htdr)) of salamander splenocytes cultured with phytohemagglutinin-p (pha) or concanavalin a (con a) in 1% fetal bovine serum (fbs)-supplemented medium are either statistically insignificant or never approach the magnitude typically observed in similarly treated cultures of frog lymphocytes. the present study confirms these findings, but also reports highly significant and reproducible pha-induced prolifer ...	1992	1473594
neuron-specific enolase-like immunoreactivity in the vertebrate retina: selective labelling of müller cells in anura.	neuron-specific enolase (nse) immunocytochemistry was carried out in retinae of goldfish, axolotl, clawed frog, cane toad, lizard, chick, guinea-pig, rabbit, rat, cat and human. with the exception of anura, strong immunoreactivity was seen in the large ganglion, amacrine cells and horizontal cells of the retina in all of the other species. photoreceptors were found to be labelled in the rat and human retina and only one cone type in rabbit. photoreceptor pedicles and ellipsoids were stained in t ...	1992	1459864
developmental expression of the xenopus int-2 (fgf-3) gene: activation by mesodermal and neural induction.	we have used a probe specific for the xenopus homologue of the mammalian proto-oncogene int-2 (fgf-3) to examine the temporal and spatial expression pattern of the gene during xenopus development. int-2 is expressed from just before the onset of gastrulation through to prelarval stages. in the early gastrula, it is expressed around the blastopore lip. this is maintained in the posterior third of the prospective mesoderm and neuroectoderm in the neurula. a second expression domain in the anterior ...	1992	1425349
isolation of lactose-binding lectins from axolotl (ambystoma mexicanum).	1. lactose-inhibitable hemagglutination activity was identified in extracts of axolotl (ambystoma mexicanum) larvae. 2. two types of lectin were isolated from extracts by affinity chromatography on lactose-sepharose. 3. a thiol-independent lectin of subunit mol. wt 15 kda and a thiol-dependent lectin of subunit mol. wt 18 kda were identified. 4. the 15 kda and a 18 kda polypeptides were weakly reactive with polyclonal anti-human galaptin serum.	1992	1424562
selective innervation of foreign muscles following damage or removal of normal muscle targets.	the restoration of a normal pattern of neural connectivity following nerve injury depends upon the selective reinnervation of appropriate postsynaptic targets. previous studies suggest that, in the neuromuscular system, recognition between regenerating motoneurons and target muscles depends upon the positions of origin of the motoneurons and muscles. in axolotls, portions of the motor pools of adjacent muscles overlap. we found that, following removal of a pair of adjacent hindlimb muscles, ante ...	1992	1383284
evolution of vertebrate igm: complete amino acid sequence of the constant region of ambystoma mexicanum mu chain deduced from cdna sequence.	cdna clones coding for the constant region of the mexican axolotl (ambystoma mexicanum) mu heavy immunoglobulin chain were selected from total spleen rna, using a cdna polymerase chain reaction technique. the specific 5'-end primer was an oligonucleotide homologous to the jh segment of xenopus laevis mu chain. one of the clones, jha/3, corresponded to the complete constant region of the axolotl mu chain, consisting of a 1362-nucleotide sequence coding for a polypeptide of 454 amino acids followe ...	1992	1382992
histochemical study of the heart of the axolotl (ambystoma mexicanum).	we have investigated the presence of cells containing monoamines, substance p, and neuron-specific enolase (nse) in the heart and in the pericardial wall of a urodele amphibian, the axolotl. fibers containing substance p-like immunoreactivity were present in the heart but not in the pericardial wall. also present in the heart were small branched cells, which stained metachromatically with toluidine blue. similar cells were found in the peritoneum and were tentatively identified as mast cells. ns ...	1992	1376564
morphological features of the myenteric plexus of the stomach of the axolotl, ambystoma mexicanum, revealed by immunocytochemistry.	the general morphology of the intramural innervation of the myenteric plexus of the axolotl stomach has been investigated using antisera raised against neuron-specific enolase and a microtubule-associated protein. additionally, the occurrence of serotonin and several peptidergic neurotransmitter/neuromodulator substances was studied. immunoreactivity for galanin, vasoactive intestinal polypeptide, substance p and neuromedin u was found in both fibres and intrinsic perikarya, whereas the serotoni ...	1992	1375207
reorganization of the ependyma during axolotl spinal cord regeneration: changes in intermediate filament and fibronectin expression.	changes in intermediate filament content and extracellular matrix material showed that the injury response of ependymal cells in lesioned axolotl spinal cord involves an epithelial-to-mesenchymal transformation, and that fibrous astrocytes are excluded from the remodeling lesion site. antibody localization was used to visualize cytokeratin-, vimentin-, and glial fibrillary acidic protein- (gfap-) containing intermediate filaments, as well as the adhesive glycoprotein fibronectin. in normal axolo ...	1992	1374657
valproic acid induced abnormal development of the central nervous system of three species of amphibians: implications for neural tube defects and alternative experimental systems.	embryos of ambystoma mexicanum, xenopus laevis, and hyperolius viridiflavus taeniatus were exposed to various concentrations of valproic acid (vpa: 0.1, 1.5, 10 mm) from blastula stage (s) 9 on up to advanced gastrulation of control embryos (s 11 1/2-12). at 10 and 5 mm vpa early development was affected in all species tested. however, the most pronounced effects occurred in ambystoma: the neural folds appeared delayed and showed a flattened and wavy shape; the neural tube was not formed and emb ...	1992	1363963
melanotropin as a potential regulator of pigment pattern formation in embryonic skin.	frozen tissue sections of developing axolotl embryos were labeled by indirect immunofluorescence with anti-alpha-msh. anti-msh immunoreactivity is first detectable in embryos when neural crest cells are migrating from the neural tube. antibody labeling is visible around the lateral and ventral edges of the neural tube and in the embryonic ectoderm. as development progresses, the amount of labeling increases greatly, particularly in developing ectoderm. western blots of soluble proteins extracted ...	1992	1329074
leydig cells in the lingual epithelium of the axolotl, ambystoma mexicanum, are immunoreactive for serotonin.	the leydig cells in the lingual epithelium of the axolotl were investigated by immunohistochemistry using serotonin antiserum. serotonin-immunoreactivity was found in their secretory granules. the physiological role of serotonin in the leydig cell, a type of exocrine cell, is unknown.	1992	1295874
monoclonal antibody st1 identifies an antigen that is abundant in the axolotl and newt limb stump but is absent from the undifferentiated regenerate.	monoclonal antibodies (mab) utilized in regeneration studies to date identify antigens that are up-regulated in the blastema. we obtained a monoclonal antibody, designated st1 (stump 1), that is reactive to an extracellular matrix (ecm) antigen exhibiting the opposite distribution; st1 is an abundant antigen of the limb stump soft tissues but is absent from within the blastema. the border between abundance and absence of mab st1 reactivity was sharp and extended as a concavity into the stump. th ...	1992	1279094
retinofugal pathways in normal and albino axolotls.	the retinofugal pathways of normal and albino axolotls have been studied by tracing the transport of radioactive materials after tritiated proline was injected into one eye. the pathways demonstrated by this method include crossed projections to the diencephalon, pretectum, and tectum, and a small component that goes to the midbrain tegmentum in the basal optic root. ipsilaterally, radioactive label was found in all of the same cerebral regions, but in much smaller quantities. although on the ba ...	1976	1276914
topological analysis of the brain stem of the axolotl ambystoma mexicanum.	the ventricular sulcal pattern and the cellular structure of the brain stem of the axolotl ambystoma mexicanum have been studied in transversely cut nissl and bodian stained serial sections. six longitudinal sulci, the sulcus medianus inferior, the sulcus intermedius ventralis, the sulcus limitans, the sulcus intermedius dorsalis, the sulcus medianus superior and the sulcus lateralis mesencephali could be distinguished. a seventh groove, the sulcus isthmi, clearly deviates from the overall longi ...	1976	1270610
the cell cycle during amphibian limb regeneration.	the duration of the cell cycle in the blastema of regenerating limbs of axolotls has been measured by means of [3h]thymidine pulse labelling and autoradiography. a chase was required to define the pulse period. an average cell cycle at 20 degrees c takes 53 h, s-phase takes 38 h; including parts of mitosis, g1 is 10 h and g2 is 5 h long. the protracted cycle and s-phase are consonant with the large genome in axolotis and other urodeles. the rapidly growing blastema probably contains a steady pop ...	1976	1270529
irradiation inhibits the regeneration of aneurogenic limbs.	the developing arms of axolotl larvae from the 2-digit stage onward and the aneurogenic arms of surgically denervated larvae maintained in parabiosis are able to regenerate after amputation. such regeneration is uniformly inhibited by local irradiation of the arm, whether innervated or not. this demonstration refutes a recent hypothesis that x-rays interfere with a special activity of nerves required for regeneration, and supports the earlier concept that x-rays act directly on those cells which ...	1976	1262820
mitotic activity and nucleic acid precursor incorporation in denervated and innervated limb stumps of axolotl larvae.	mitotic activity and dna and rna precursor incorporation were compared in innervated regenerating limbs and in denervated, non-regenerating limbs on days 8 and 9 post-amputation. innervated limbs had well-developed cone stage blastemas which showed high cellular mitotic indices and h3-thymidine labeling indices of 0.40-0.50 and h3-uridine labeling indices of 0.50-0.75. in contrast, denervated limbs showed dedifferentiated cells distally under thickened wound epithelia, but essentially no mitotic ...	1976	1262816
alterations in resting membrane properties during neural plate stages of development of the nervous system.	1. the mean resting membrane potential of cells in the neural plate of axolotl embryos increases from -25 to -45 mv (maximum values from -35 to -60 mv) when the embryos move from early to mid-neural plate stages of development. 2. increasing the extracellular [k] to 20 mm shortly before the spontaneous increase in resting potential occurs causes neural plate cells to hyperpolarize. 3. a moderate increase in [k]omicron does not hyperpolarize the membrane of neural plate cells at earlier stages or ...	1976	1255516
low resistance junctions between mesoderm cells during development of trunk muscles.	1. electrical connexions between mesoderm cells have been examined during the formation of somites in xenopus laevis, bombina orientalis and ambystoma mexicanum. 2. in xenopus the resting potentials of presumptive myotome cells (-65 + 2 mv, s.e. of mean) and somite muscle cells (-65 +/- 0-6 mv s.e. of mean) were 40 mv, greater than dermatome cells (-25 +/- 0-6 mv, s.e. of mean). similar differences were found in bombina and ambystoma. 3. in all three species cells of the dermatome layer of the m ...	1976	1255515
horizontal cell potentials: dependence on external sodium ion concentration.	the membrane potential of the horizontal cell of the axolotl is highly dependent on the extracellular concentration of sodium. experimental results reported here are consistent with the suggestion that in the dark the receptors release a synaptic transmitter which increases primarily the sodium conductance of the postsynaptic membrane. externally applied aspartate or glutamate depolarizes the horizontal cell membrane and eliminates the light response of the horizontal cell. however, it appears t ...	1976	1251211
non-innervated sense organs of the lateral line: development in the regenerating tail of the salamander ambystoma mexicanum.	new lateral organs (neuromasts) are formed in regenerating tails of the larvae of a urodele, the axolotl (ambystoma mexicanum), even in the absence of the lateral line nerve, as confirmed by electron microscopic examination. the non-innervated organs are similar to normal innervated organs. the hair cells are polarized in opposite directions, and despite the lack of nerve endings, contain synaptic bodies, which in normal innervated organs are found in relation to afferent boutons.	1976	1249591
[a change in the concentration of potassium and sodium during early axolotl embryogenesis].		1975	1214990
neural crest and early fore limb development in amphibia.	anterior trunk neural folds were exchanged between neurula stages 15 to 16 (harrison) of several triturus species and ambystoma mexicanum. donor neural crest cells migrated ventrad before and during initial bud formation. they lined the early lumb epidermis and became incorporated into the young blastema. donor melanophores and non-melanophores contributed substantially to host limb buds.	1975	1211655
[influence of environmental salinity on blood ion concentration of the intact and hypophysectomized axolotl. effect of prolactin].		1975	1205118
the effects of rotation and positional change of stump tissues upon morphogenesis of the regenerating axolotl limb.		1975	1204936