| 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 |
| 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 |
| 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 |
| developmental regulation of a matrix metalloproteinase during regeneration of axolotl appendages. | removal of specific extracellular matrix (ecm) components has been implicated in the initiation of salamander limb regeneration. remodeling of the ecm at the distal stump is necessary for the release of cells that eventually contribute to the blastema. several matrix metalloproteinases (mmps) have been well characterized as important to various physiological and pathological processes, such as bone remodeling and tumor invasion. the goal of this study is to identify and characterize mmps that mo ... | 1994 | 7813787 |
| immunofluorescent confocal analysis of tropomyosin in developing hearts of normal and cardiac mutant axolotls, ambystoma mexicanum. | tropomyosin is a major component of the thin filaments in organized myofibrils of cardiac muscle cells. a purported role for this protein is to prevent myosin thick filaments from interacting with actin thin filaments until the cell contracts. recently, tropomyosin has been implicated in actin filament formation/stabilization as well. in the cardiac mutant axolotl, ambystoma mexicanum, heart development is arrested. mutant embryos form hearts that fail to beat due to a lack of organized sarcomer ... | 1994 | 7779690 |
| 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 |
| neuroepithelial endocrine and nervous system in the respiratory tract of cynops pyrrhogaster with special reference to the distribution of nitric oxide synthase and serotonin. | the respiratory tract of urodeles harbours an intramural nerve network comprising an innervated system of neuroepithelial endocrine (nee) cells. however, striking differences have been noted between phylogenetically closely related species. zamboni- or formaldehyde-fixed whole-mount preparations and sections of the saclike lungs of a japanese salamander, cynops salamander, cynops pyrrhogaster, have been investigated for the immunocytochemical detection of nitric oxide synthase (nos), serotonin ( ... | 1994 | 7529073 |
| surface contraction and expansion waves correlated with differentiation in axolotl embryos--i. prolegomenon and differentiation during invagination through the blastopore, as shown by the fate map. | we have discovered a series of expansion and contraction, solitary waves that correlate with discrete steps of differentiation in the urodele amphibian axolotl embryo (ambystoma mexicanum). here we examine in detail the proposition that the blastopore is a set of differentiation waves. we superimposed the image of the axolotl fate map onto our digitized video images of normal gastrulation and matched the fate map to pigmentation irregularities on the embryo. we were then able to track the invagi ... | 1994 | 16649266 |
| ultrastructure of merkel-like cells labeled with carbocyanine dye in the non-taste lingual epithelium of the axolotl. | fluorescent carbocyanine dye (dii), applied to the glossopharyngeal (ix) nerve of the axolotl, transneuronally labeled solitary cells in the non-taste lingual epithelium. with diaminobenzidine (dab), the dii was photoconverted to a dark, electron-dense product. the labeled cell had a large nucleus with invaginations, dense-cored vesicles in the cytoplasm, and finger-like processes. these are reminiscent of morphological features of cutaneous merkel cells, suggesting that solitary cells innervate ... | 1994 | 7816314 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| activities of acetylcholinesterase, choline acetyltransferase, and catecholamine production in the spinal cord of the axolotl ambystoma mexicanum during forelimb regeneration. | amputation of an axolotl limb causes severance of the brachial nerves, followed by their regeneration into a blastema. it is known that these nerves provide a neurotrophic factor to blastemal cells. to approach the problem of the response of spinal cord nerve centers to forelimb amputation, we have studied biosynthetic activities in the nerve centers involved in axonal injury during limb regeneration. we report that the acetylcholinesterase (ache) activity in the spinal cord is elevated 2 days ( ... | 2013 | 7840938 |
| 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 |
| 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 |
| 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 |
| morphogenetic effects of 9-cis-retinoic acid on the regenerating limbs of the axolotl. | 9-cis-retinoic acid has recently been found to be a high affinity ligand for the retinoic x receptor (rxr). rxrs are believed to be involved in metabolic activities rather than in morphogenetic ones. interestingly, rxr has been found to form heterodimers involving other receptors from the steroid family, such as the thyroid hormone receptor, vitamin d receptor or retinoic acid receptors (rars). in this paper we examined whether or not 9-cis-retinoic acid had any morphogenetic properties on the r ... | 1994 | 28305887 |
| regulation of interrenal secretion in the axolotl, ambystoma mexicanum. | the regulation of corticosteroid secretion of the adrenal cortex (interrenal tissue) of axolotl (ambystoma mexicanum) was studied using in vitro preparations of kidney containing interrenal tissue. normally, 0.3-0.65 ng/5 min corticosterone and 0.15-0.3 ng/5 min aldosterone were released from the tissue. regulatory peptides were effective in the following range: acth = arginine vasotocin > urotensin ii > angiotensin ii. they stimulate an elevation of corticosterone (plus 0.2-1 ng/5 min) and of a ... | 1994 | 7813601 |
| characterization of immunoglobulin heavy chain variable regions in the mexican axolotl. | | 1994 | 7506234 |
| 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 |
| 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 |
| 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 |
| a histological processing technique that preserves the integrity of calcified tissues (bone, enamel), yolky amphibian embryos, and growth factor antigens in skeletal tissue. | we have devised a processing technique to embed calcified tissues, such as bone and tooth enamel, in paraffin, to preserve the delicate antigenic sites of molecules such as growth factors. the same technique, omitting the decalcification step, allows delicate tissues, such as axolotl embryos (ambystoma mexicanum) containing large yolk masses, to be easily handled during tissue processing and to be serially sectioned. specimens were all fixed in periodate-lysine-paraformaldehyde (plp) fixative at ... | 1993 | 7689084 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| stability of positional identity of axolotl blastema cells in vitro. | previous grafting experiments have demonstrated that cells from non-contiguous positions within developing and regenerating limbs differ in a property referred to as positional identity. the goal of this study was to determine how long the positional identity of axolotl limb blastema cells is stable during culture in vitro. we have developed an assay for posterior positional properties such that blastema cells can be cultured and then grafted into anterior positions in host blastemas, to determi ... | 1993 | 28305994 |
| insulin counters the glycogenolytic effect of arginine vasotocin in liver pieces from the axolotl, ambystoma mexicanum, cultured in vitro. | in organ cultures of liver tissue from the axolotl, ambystoma mexicanum, 1 nmol/l arginine vasotocin (avt) increased tissue cyclic amp (camp) concentration, activated glycogen phosphorylase, and caused glycogen breakdown and glucose release. addition of 10 nmol/l insulin had no effect on any of these parameters. addition of glucagon together with avt caused a further increase in tissue camp but not in glucose release. ten nanomoles per liter of insulin added to the cultures 5 min before 1 nmol/l ... | 1993 | 7681019 |
| 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 |
| mesoderm differentiation in early amphibian embryos depends on the animal cap. | embryos of ambystoma mexicanum from the late morula to the late blastula stage were dissected and cultivated in varying combinations. the marginal zone (presumptive mesoderm) when isolated together with the vegetal region differentiated to notochord after dissection from early blastulae, but did not differentiate to other tissues. when isolated from middle to late blastulae, in addition myoblasts and mesenchyme were formed. the marginal zone isolated together with the animal region (presumptive ... | 1993 | 28305977 |
| 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 |
| affinophoresis as a test of axolotl accessory limbs. | | 1993 | 8302896 |
| development and regeneration of limbs in the short toes axolotl mutant. | | 1993 | 8302894 |
| analysis of the mutant axolotl short toes. | | 1993 | 8302893 |
| 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 |
| 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 |
| 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 |
| asymmetric effects of retinoic acid on pattern formation in the transverse axes of regenerating axolotl limbs: test of a hypothesis. | | 1993 | 8115389 |
| rna from normal anterior endoderm/mesoderm-conditioned medium stimulates myofibrillogenesis in developing mutant axolotl hearts. | in the axolotl, ambystoma mexicanum, a recessive cardiac lethal mutation causes an incomplete differentiation of the myocardium. mutant hearts do not contain sarcomeric myofibrils nor do they beat. we have previously shown that normal anterior endoderm, medium conditioned by endoderm, or total rna extracted from endoderm stimulates differentiation of mutant hearts in culture as indicated by the presence of organized myofibrils and rhythmic contractions of the "rescued" mutant heart tube. in this ... | 1993 | 7516783 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| caenogenesis, developmental variability, and evolution in the carpus and tarsus of the marbled newt triturus marmoratus. | in this paper, after a comparative analysis of the development of triturus marmoratus, we explore the existence of caenogenetic events and their ontogenetic and phylogenetic consequences. the adult morphology of the triturus marmoratus limb, in terms of number and spatial arrangement of skeletal elements, agrees with the general pattern of urodeles. the congruence in the typical pattern of adult morphology does not hint at the striking differences in embryonic development. these differences can ... | 1992 | 28568662 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| nucleotide sequence of a cdna encoding wnt-1 of the mexican axolotl ambystoma mexicanum. | | 1991 | 2017393 |
| 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 |
| structural changes in the proximal tubule of the short-toes axolotl mutant. | a recessive lethal mutation in axolotls that involves the kidneys, the mullerian ducts and the limbs was described by humphrey (1967). in the present experiments, we have examined the structural defects that lead to kidney malfunction and subsequent death in homozygous mutants and compared the defects with those observed in other axolotls lacking this mutant gene. the ultrastructure of the mesonephric kidney was studied in homozygous s/s short-toes axolotls with ascites and/or edema and hemorrha ... | 1991 | 18621179 |
| distribution of sulfhydryloxidase (sox) immunoreactivity in the testis of the axolotl (ambystoma mexicanum) (amphibia, urodela). | immunohistochemical localization of sulfhydryloxidase (sox) has been examined in the testis of the axolotl (ambystoma mexicanum). the urodelan testis contains germ cells in various phases of differentiation from primordial germ cells to mature spermatozoa. sox immunoreactivity is present in mitochondria of primordial germ cells and primary spermatogonia and declines within the population of secondary spermatogonia, suggesting, that the antibody used to localize sox may serve to estimate the deve ... | 1991 | 18621168 |
| endothelial nuclear bulging: morphological evidence for an intraglomerular perfusion regulating mechanism in the axolotl. | kidneys of the axolotl (ambystoma mexicanum: urodela, amphibia) have been investigated by light and electron microscopy as well as microvascular corrosion casting. numerous glomerular endothelial nuclei bulge into the glomerular capillary lumen. it is concluded that these cells virtually stop the blood-flow in the respective vessel by blockage of erythrocyte passage. a proposal for an intraglomerular regulation mechanism of capillary perfusion (and thus filtration) by endothelial isometric contr ... | 1991 | 18621164 |
| nucleotide sequence of a cdna encoding wnt-1 of the mexican axolotl ambystoma mexicanum. | | 1990 | 2259633 |
| 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 |
| 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 |
| effects of tributyltin oxide on the skeletal structures of developing and regenerating limbs of the axolotl larvae, ambystoma mexicanum. | | 1990 | 2279120 |
| 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 |
| 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 |
| [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 |
| 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 |
| the effect of retinoic acid on positional memory in the dorsoventral axis of regenerating axolotl limbs. | we investigated the effect of retinoic acid (ra) on pattern regulation in the dorsoventral (dv) axis of regenerating axolotl limbs. half and double half dorsal and ventral zeugopodia (lower arms or legs) were amputated through their distal ends, and 4 days later the animals were injected intraperitoneally with 50 (large animals) or 100 (small animals) micrograms ra/g body wt. half and double half dorsal and ventral zeugopodia of uninjected axolotls, and sham-operated zeugopodia of untreated and ... | 1990 | 2358123 |
| 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 |
| in vitro control of blastema cell proliferation by extracts from epidermal cap and mesenchyme of regenerating limbs of axolotls. | the presence of a mitogenic activity in limb blastemas of axolotls was detected in crude extracts of blastemas at the mid-bud stage. the mitogenicity of the extracts was estimated from the mitotic index of blastema cells grown for 6 days in the presence of limb blastema extracts, with colchicine present for the last 2 days. all the extracts tested (whole blastema, blastemal mesenchyme, epidermal cap) significantly enhanced proliferation of blastema cells. the highest stimulation factors we obser ... | 1990 | 28305671 |
| melanin as a natural germ cell marker for intraspecific transplantation experiments in ambystoma mexicanum (urodela, amphibia). | in urodele amphibians, the lack of a reliable germ cell marker restricts the experimental study of the germ lineage. in the present work, we conducted genetic and histological analyses in order to demonstrate that melanin from oocytes constitutes a germ cell marker available for intraspecific experiments in ambystoma mexicanum. then, using this marker, we implanted germ cells from undifferentiated gonads (stage 48) into the blastocoel of host embryos and investigated their fate and determined st ... | 1990 | 28305537 |
| 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 |