Publications

development of locomotor behavior in wild type and spastic (sp/sp) axolotls, ambystoma mexicanum.	the homozygous recessive spastic mutant found in the mexican axolotl shows violent coiling and thrashing behavior when subjected to strong tactile or electrical stimulation. in order to establish the time of onset of the first behavioral manifestation of the spastic gene, an etiological analysis of the ontogeny of swimming behavior in mutants and wild type siblings was undertaken. the locomotor patterns shown by embryos in response to an electrical stimulus were analyzed quantitatively from the ...	1975	1202151
inter- and intramyotomal gap junctions in the axolotl embryo.		1975	1181218
multiple regeneration from axolotl limb stumps bearing cross-transplanted minced muscle regenerates.		1975	1181217
proceedings: development of the ipsilateral visual projection in axolotls treated with thyroxine.		1975	1177125
[activity and isoenzymes of lactate dehydrogenase in tissues of amphibians (xenopus laevis, ambystoma mexicanum, triturus alpestris and vulgaris) and the response in the fat body of xenopus males to gonadotropin injection (author's transl)].	lactate-dehydrogenase activity was determined by the optical test method using pyruvate as substrate and the isoenzymes were separated by vertical starch gel electrophoresis. species-specific and organ-specific characteristics of the total activity and the isoenzyme patterns of the four amphibian species are compared with those of rat and mouse. application of gonadotropin increases the amount of soluble protein and the lactate-dehydrogenase activity in the fat body of xenopus and the isoenzyme ...	1975	1176091
pathological changes of golgi complex in hemocytoblasts of spleen of young axolotls after x-irradiation.		1975	1172336
normal stages of development of the axolotl. ambystoma mexicanum.		1975	1167837
experimental studies on a lethal gene (1) in the mexican axolotl, ambystoma mexicanum.	1. gene ł is a recessive lethal factor found in the white strain of axolotls. animals heterozygous for the gene are phenotypically normal. when mated with each other they give offspring 25% of which exhibit the lethal effects of the gene. 2. the ł/ł homozygotes develop normally to an advanced embryonic stage (harrison stage 40) before the effects of the gene are first manifested. they then come to display a characteristic combination of abnormalities, including a disproportionately small head, s ...	1975	1167371
[axolotl 1975].		1975	1164736
proceedings: axolotl-liver in organ culture. i. some morphological and biochemical parameters.		1975	1163296
intracellular recordings of rod responses during dark-adaptation.	1. dark-adaptation of rod photoreceptors has been studied in the isolated axolotl (ambystoma mexicanum) retina by intracellular recordings. rod responsiveness was greatly reduced immediately after a 30 sec partial bleach, but partially recovered with time in the dark. 2. in parallel spectrophotometric measurements using isolated retinas, regeneration of the rod pigment could not be detected after a 30 sec bleach. 3. during rod dark-adaptation, the response of a rod to a given stimulus increased ...	2005	1151778
incorporation of labeled amino acids into proteins of the cell organelles of muscle tissue during the restoration of the regenerative capacity of the limbs of axolotl, suppressed by x-irradiation.	the incorporation of labeled amino acids into the total proteins of muscle tissue and cell organelles during the regeneration of limbs of axolotls and after the suppression of the regenerative capacity by x-irradiation and its experimental restoration were investigated. in the case of suppression of the regenerative capacity of the limbs by x-irradiation, the protein synthesis in the muscle tissue is impaired. the intensity of the incorporation of labeled amino acids into the proteins of a homog ...	1975	1129636
cell cycles in the early development of axolotl.	in axolotl embryos, during the course of development, the generation time increases, chiefly on account of a lengthening of the phase of dna synthesis, the longest in the cell cycle. at the stages of the middle blastula and early gastrula, the g1 phase is shorter than in the g2 phase, while at the neurula stage, the g1 phase is far longer than the g2 phase. cells of the chordamesoderm pass through the cycle nonuniformly during gastrulation: a period with a very low index of labeled nuclei and sl ...	1975	1124434
hormonal stimulation as an aid to artificial insemination in ambystoma mexicanum.		1975	1116071
growth and respiration of regenerating tissues of the axolotl tail.	changes in the weight and oxygen consumption were studied during regeneration of the tail in adult axolotls and larvae. the curve of the increase in weight of the regenerating tail in both age groups is s-shaped. the intensity of respiration of the regenerating tail increases in adult axolotls and in larvae at the blastema stage; in adult axolotls there is also a second increase in the intensity of respiration of the regenerating tail during differentiation of the muscles. the relationship betwe ...	1975	1114357
isozymic patterns of lactate dehydrogenase in whole embryos and adult tissues of the mexican axolotl.		1975	1109827
studies of muscle proteins in embryonic myocardial cells of cardiac lethal mutant mexican axolotls (ambystoma mexicanum) by use of heavy meromyosin binding and sodium dodecyl sulfate polyacrylamide gel electrophoresis.	in the mexican axolotl ambystoma mexicanum recessive mutant gene c, by way of abnormal inductive processes from surrounding tissues, results in an absence of embryonic heart function. the lack of contractions in mutant heart cells apparently results from their inability to form normally organized myofibrils, even though a few actin-like (60-a) and myosin-like (150-a) filaments are present. amorphous "proteinaceous" collections are often visible. in the present study, heavy meromyosin (hmm) treat ...	1976	1107335
apical secretion from taste bud and other epithelial cells in amphibians.	taste buds of the axolotl, ambystoma mexicanum, contain cells, previously undescribed in this species, which have a long apical process, and are similar to the type iii cells of mammalian taste buds, and to the gustatory cells in fish. in the supporting cells, there is evidence of periodic decapitation, in addition to secretion by exocytosis. bilaminar fragments, which are leaf-shaped bodies formed of two dense laminae separated by a lucent gap, protrude from the apical microvilli of the support ...	1976	1086718
proceedings: the brain stem of the axolotl ambystoma mexicanum and the frog rana esculenta.		1975	1082712
restoration of vision in genetically eyeless axolotls (ambystoma mexicanum).		1976	1082417
association of an ultraviolet irradiation sensitive cytoplasmic localization with the future dorsal side of the amphibian egg.	drastic alterations in neural morphogenesis can be induced by ultraviolet irradiation of the amphibian egg. the target area of u.v. was determined either by direct irradiation of various regions of the egg or by comparing the area of the u.v. hit with the location of the dorsal lip. axolotl eggs which displayed easily recognizable gray crescents were employed for the direct irradiation experiments and albino axolotl eggs were used for a comparison of the u.v. sensitivity of the animal and vegeta ...	1975	1078573
[growth of meckel's cartilage in axolotl (urodelean amphibian)].		1976	1070669
[early activation of ribosomal rna synthesis in axolotl embryos].	the incorporation of labeled precursors (3h- and 14c-uridine) into the fractions of salt-insoluble rnas and or rrna was studied in the axolotl embryos at different stages of early development (from the end of synchronous cleavage divisions until the end of gastrulation). rna preparations isolated from the embryos at all stages studied contained incorporated radioactivity. the radioactivity of salt-insoluble rnas markedly increased at the beginning of blastulation and continued to grow, but less ...	1975	1052341
regeneration-promoting properties of tribenoside in amblystoma mexicanum.	tribenoside in a dose of 100 mg/kg i.p. significantly accelerates the regeneration of puncture wounds in the caudal membrane of amblystoma mexicanum. a dose of 200 mg/kg exerts a less-pronounced vulnerary effect and is occasionally toxic. tribenoside also stimulates regeneration in this species when added to bath fluid in a concentration of 1:400,000 (exposure for 6 h daily). a concentration of 1:200,000 is less effective and has a slightly irritant effect on the tissue. 14 days after operation, ...	1976	1037626
morphological and biochemical abnormalities in hearts of cardiac mutant salamanders (ambystoma mexicanum).	the effect of homozygosity for recessive gene c in ambystoma mexicanum is the absence of a heartbeat even though initially heart development appears normal. mutant embryos (c/c) are first distinguishable from their normal siblings (+/+;+/c) at stage 34 (7 days after fertilization) when the normals develop contracting hearts. the mutant hearts at this stage, upon gross examination, appear structurally normal but fail to beat. nevertheless, the mutants survive through stage 41, which is about 20 d ...	1976	1034176
[differentiation tendency in mesodermal germ layer. isolation experiments on morula, blastula and gastrula stadia of axolotl (ambystoma mexicanum)].		1976	1024382
[segregation of amphibian cns. analysis of induction process using combination experiments in ambystoma mexicanum].		1976	1023592
[properties of neurons of the tectal portion of the visual system of the axolotl ambystoma mexicanum].	in the tectum opticum of the adult neotenic a. mexicanum, responses of single neuronal units to diffuse illumination and moving visual stimuli have been investigated. of 111 unites investigated, 27 are presented by tectal neurons, their maximum distribution being observed at a depth of 500-600 mu. in superficial layers 9 ipsi-elements were found; their receptive fields are located in the antero-dorsal part of the visual field, at both sides of the body axis. among the units identified as the ter ...	2007	1020556
satellite cells in the limb musculature of the axolotl.		1976	1016334
spermatogenesis and 3beta-hsdh activity in the testis of the axolotl.		2003	1012324
on the determination of the dorso-ventral polarity in the amphibian embryo: suppression by lactate of the formation of ruffini's flask-cells.	cells isolated from the vegetal hemisphere of the blastula of ambystoma mexicanum differentiate spontaneously into fibroblast-like cells. similar cells may be formed from animal cells, provided they are induced either by vegetal cells or by li+. we have found that lactate and various inhibitors of rna synthesis suppress the spontaneous cell differentiation. the effect of lactate differs from that of the other agents in so far as lactate must be present before the second day of culture to suppres ...	1976	1003073
ontogeny of ldh-isozymes in mexican axolotl, ambystoma mexicanum by thin-layer isoelectric focusing.	the ontogeny of lactate dehydrogenase (ldh) isozymes in developing mexican axolotl, ambystoma mexicanum was investigated by thin-layer isoelectric focusing in polyacrylamide gel. the isoelectric points (pi values) of the isozymes were determined. the minor components generally remained masked during conventional electrophoresis, but became sharp as isofocusing progressed. we identified in developing eggs and embryos five major ldh isozymes, which could also be traced in the ovarian eggs. all the ...	1976	992242
diploid gynogenesis in the mexican axolotl.	gynogenetic diploid axolotls were produced by activating eggs with ultraviolet-inactivated sperm, and then subjecting the activated eggs to heat shock. optimal conditions for ultraviolet inactivation of the sperm, and for suppression of the second meiotic division by heat shock, were established. gynogenetic diploids produced by these procedures included progeny homozygous for recessive alleles carried by a heterozygous mother. gynogenesis could, therefore, be used to uncover new mutations more ...	1976	971806
a staging system for forelimb regeneration in the axolotl, ambystoma mexicanum.	a staging system has been devised for normal regeneration from the upper arm in the mature axolotl. it consists of seven externally definable stages: (1) wound healing (wh): (2) dedifferentiation (dd); (3) early bud (eb); (4) medium bud (mb); (5) late bud (lb); (6) palette (pal), and (7) digital outgrowth (do). serial histological sections of 38 regenerating limbs were used to correlate gross stages with microscopic events in the regenerative process.	1976	966285
protein synthesis in lethal nucleocytoplasmic hybrids between the species pleurodeles waltlii michahelles and ambystoma mexicanum shaw (urodele amphibians) obtained by nuclear grafting.	using polyacrylamide gel electrophoresis, proteins stemming from the nucleus of the donor species in nucleocytoplasmic hybrids were determined. the interspecific lethal nucleocytoplasmic hybrids of pleurodeles waltlii and ambystoma mexicanum were studied. the presence of these proteins at the blastula or early gastrula stages attests to the early nuclear control of their synthesis.	1976	965910
thin-layer isoelectric focusing of soluble and insoluble lens extracts from cataractous and normal mexican axolotl (ambystoma mexicanum).		1976	949994
how x-rays inhibit amphibian limb regeneration.	the effects of an inhibiting dose of 2,000 rad of x-rays on the regenerating limbs of axolotl larvae have been examined in a histological and cytological study. particular attention was paid to the mitotic indices of normal and irradiated epidermal and blastemal cells. both the characteristic pattern of epidermal mitotic stimulation which normally follows amputation and the later increase in blastemal mitoses are suppressed by irradiation. in most cells the effects are permanent, but in a small ...	1976	939955
[participation of irradiated tissues in the formation of limb regenerates in axolotls].		1976	939173
[relationship between mitotic phases at different stages of embryonic development of axolotl].	indices and durations of mitotic phases and interphase have been determined in the axolotl embryos at the late blastula, early gastrula and mid-neurula stages. the data obtained suggest that the ratio of mitotic phases changes during embryogenesis and differs in different rudiments of the embryo at the same developmental stage.	1976	934593
analysis of spastic: a neurological mutant of the mexican axolotl.		1977	928456
genetic and experimental studies on three associated mutant genes in the mexican axolotl: st (for stasis), mi (for microphthalmic) and h (for hand lethal).	three mutant genes, st, mi, and h, were discovered in an axolotl male received from mexico city. all three are recessive to their normal alleles, and appear to segregate independently. larvae homozygous for st (for stasis) suffer blockage of the circulation at hatching or shortly after, and the majority soon die; any surviving live only a few weeks at most. the mi/mi (microphthalmic) can be identified at the feeding stage. none survives more than a few days. the h/h (hand lethals) live until the ...	1977	925667
neuroanatomy of spastic, a behavior mutant of the mexican axoloti: purkinje cell distribution in the adult cerebellum.	the spastic mutant, found in the mexican axolotl, shows swimming coordination and equilibrium deficiencies. histological analyses of wild-type and spastic mutant cerebella previously characterized in physiological studies revealed changes in purkinje cell location in the mutant auricle or vestibulo-cerebellum. purkinje cells are "translocated" ventrally correlated with a similar translocation of vestibular single units described previuosly (ide, '77). where wild-type purkinje cells are distribut ...	1977	915044
neurophysiology of spastic, a behavior mutant of the mexican axoloti: altered vestibular projection to cerebellar auricle and area acoustico-lateralis.	the spastic mutant of ambystoma mexicanum shows deficiencies in swimming coordination and equilibrium. behavior "phenocopy" experiments done previously indicated that vestibular projections to cerebellum and hindbrain interneurons might be responsible for mutant behavior patterns. to test function in mutant vestibular projections, single unit recordings were carried out in the vestibulo-cerebellum (auricle) and hindbrain area acoustico-lateralis (aay) of wild-type and mutant animals in response ...	1977	915043
cardiac mutant salamanders: evidence for heart induction.	homozygosity for gene c in ambystoma mexicanum results in no detectable heartbeat in situ. alteration of the cardiac environment through organ culture results in rapid initiation of spontaneous heartbeat, indicating that absence of cardiac function in situ is not the result of failure of embryonic induction.	1977	908918
a scanning electron microscopic comparison of the development of embryonic and regenerating limbs in the axolotl.	a comparison between the surface features of embryonic limb development and limb regeneration was made in the axolotl. scanning electron microscopy revealed an overall similarity between embryonic and regenerating limbs. a notable feature was the lack of a morphologically discrete apical epidermal specialization on the surface of any of the limbs. histological preparations revealed no thickening of the apical epidermis in embryonic limbs. there is a definite thickening of the apical epidermis in ...	1977	908913
thyroxine-induced gill resorption in the axolotl (ambystoma mexicanum).		1977	903970
dosage effects of the white (d) and melanoid (m) genes on pigment pattern in the mexican axolotl, ambystoma mexicanum, shaw.		1977	892230
control of anteroposterior pattern in the axolotl forelimb by a smoothly graded signal.	(1) it is shown that the number of cartilage elements in an experimentally produced reduplicated limb depends on the width of competent tissue between pieces of flank tissue. (2) seventy well formed reduplications were examined on the assumption that the difference in the number of elements between them results from small differences in graft position. (3) all the reduplications are symmetrical along their entire length. (4) all possess the most posterior structures at both edges with other elem ...	1977	886255
determination of anteroposterior polarity in the axolotl forelimb by an interaction between limb and flank rudiments.	1. it is shown that the mesoderm in the prospective forelimb-bud of the axolotl embryo is thickened and divided into somatic and splanchnic layers, while that of the flank is thinner and divided. the first sign of the limb-bud itself appears at stage 38. 2. a whole, a half or a third of a limb rudiment can develop into a normal or reduplicated limb when transplanted to the flank. 3. an anterior half of a limb rudiment fails to develop when transplanted to the head but will do so if accompanied b ...	1977	886254
experimental studies on a mutant gene (p) causing premature death of ambystoma mexicanum embryos.	the premature death (p) mutation is a recessive lethal, which, in the homozygous condition, gives rise to a complex of abnormalities. the mutant embryos develop only to stage 37, at which time disintegration of superficial tissue begins. many of the abnormalities observed in sections of the stage-37 mutant embryo are related to its failure to establish a functioning circulatory system, or to the resulting edema and/or ascites that distend the abdomen and flanks. there are, however, abnormalities ...	1977	886253
[heat production in the early stages of axolotl growth according to direct and indirect calorimetry findings].	the level of energetic metabolism of the growing axolotls was studied by the methods of direct and indirect calorimetry. just after the hatching the heat production of the larvae calculated by the gas exchange exceeds markedly the level of heat production measured by the calorimeter. during the subsequent growth the level of heat production changes as a transitional process, so that therafter indirect calorimetry gives constantly higher values of energetic metabolism than direct one.	1977	882247
[desynchronization of cell division during the early development of the axoloty, loach and salmon].	patterns of a relative measure of asynchrony r of the cell population have been studied by means of a mathematical model of the kinetics of cell population which allows to follow the distribution of cells by the mitotic cycle phases in time. the application of the criterion r for the analysis of the patterns of desynchronization of cell divisions in the early embryogenesis of axolotl, loach and salmon has shown, that, unlike the smooth change of the asynchrony measure in the model populations wi ...	1977	882238
quantitative studies of the reactions to horizontal angular accelerations in axolotls. i. the head-turning reflexes of normal animals.	1. artifically metamorphosed axolotls were exposed to both brief (impulse) and long-lasting horizontal angular accelerations on a turn-table. the animals responded with a head-turning reaction. 2. the general course of the reaction to impulse acceleration was independent of stimulus intensity. the velocity of the head movement first increased to a maximum exponentially and then decreased in a negative exponential manner. stimulus intensity had a linear relationship to the mean maximum velocity a ...	1977	870596
fiber counts of regenerating peripheral nerves in axolotls and the effect of metamorphosis.	counts have been made of myelinated and unmyelinated fibers in the sixteenth nerve root of the axolotl, before, during and after regeneration following nerve section. there is no loss of myelinated fibers. many collateral sprouts are formed and eventually withdrawn. regeneration during metamorphosis is similar but there is more sprouting. there is no fiber loss from cut nerves in metamorphosis. this suggests that rising thyroid hormone levels are not in themselves detrimental to nerves without p ...	1977	864039
the timing of morphogenetic events in the regenerating forelimb of the axolotl, ambystoma mexicanum.		1977	863102
evidence for abnormal heart induction in cardiac-mutant salamanders (ambystoma mexicanum).	homozygosity for simple recessive gene c in axolotl embryos results in the absence of a heartbeat. gene c alters the morphology of the mutant anterior endoderm - the primary heart inductor.	1977	860120
the development of monamine-containing neurons in the brain and spinal cord of the salamander, ambystoma mexicanum.	the distribution of monoamine-containing neurons in the cns of the developing and adult axolotl, ambystoma mexicanum, has been investigated using the histochemical fluorescence technique of falck and hillarp combined with microspectrofluorimetry. the earliest catecholamine-containing neurons to be detected are located in the ventral ependymal zone of the spinal cord at the time of hatching (stage 41). between stages 43 and 46, catecholamine fluorescence can be detected in neurons in the followin ...	1977	856887
factors influencing ovulation in the mexican axolotl as revealed by induced spawnings.	axolotl females may be induced to spawn by injecting them with small doses of fsh prior to mating. data on the different categories of spawnings obtained by this procedure have established the following points. (1) spawnings of injected females completely without fertile eggs are small (173 eggs average). courtship occurred in some of the matings (spermatophores found) but not in all. spawnings of injected but uninseminated females re-mated with a second (or third) male, not becoming inseminated ...	1977	845578
developmental interactions in the growth and branching of the lateral dendrite of mauthner's cell (ambystoma mexicanum).		1977	838120
[development of gonads transplanted homoplastically in limbs of sexually immature axolotls].	graft development depends on sexual maturation of the host. three successive steps in development of transplants have been demonstrated: somatic growth, gonial division and germinal maturation. sexual maturity occurs earlier in females than in males.	1976	821644
[transplantation into the blastocoel of pleurodeles waltlii michah., of blastomers isolated from blocked blastulae obtained from interspecific nuclear transplants between ambystoma mexicanum shaw. and ambystoma dumerilii dugès (urodele amphibians)].	ectodermic blastomeres from arrested nucleocytoplasmic blastulae obtained by nuclear graft between ambystoma mexicanum (a. m.) and ambystoma dumerilii (a. d.), are transplanted in the blastocoele of recipient pleurodeles waltlii blastulae. histo-autoradiographic analysis shows that hybrid cells have cellular affinities and multiplication capacities very different from normal ambystoma mexicanum blastulae isolated cells. the possibility that a revitalisation of lethal blastomeres can occur should ...	1975	813905
[demonstration of rna synthesis during segmentation in the axolotl embryo].	study of the incorporation of 3h-uridine in cleaving embryo of axolotl has shown a nuclear rna synthesis during the period of synchronous cleavage (6th cycle) as well as after the onset of asynchronous divisions (9th or 10th cycle). in the early development of the axolotl, the extent of the transcription phase looks to be an essential element of the quantitative control of gene activity.	1975	811409
[activities of protein synthesis during the development of lethal nucleocytoplasmic hybrids obtained by nuclear graft between ambystoma mexicanum shaw and ambystoma dumerilii duges (amphibia, urodeles)].	a comparative study of proteinograms and zymograms (ldh, mdh) has been carried out at different ontogenic stages, in ambystoma mexicanum (a.m.), ambystoma dumerilii (a.d.) and nucleocytoplasmic hybrids 2 n a.d/cytoplasm am. it appears that 2 n a.d. nucleus, grafted in a.m. cytoplasm expresses only a part of its potentialities, which could account for lethality of the nucleocytoplasmic hybrids.	2014	809209
[evolution of xenografts of embryonic gonads and juvenile ovaries from ambystoma mexicanum shaw, transplanted into triturus alpestris laur].	gonad primordium of ambystoma mexicanum when grafted at tail-bud stage on triturus alpestris is indefinately tolerated. testis or ovaries derived from those grafted embryonic gonads follow their differentiaion and reach sexual maturity. axolotl juvenile ovaries transplanted in triturus alpestris are also tolerated; the ovocytes achieve the entire vitellogenesis but are not able to be laid.	1975	809199
[morphogenesis of the anterior limb primordium and its histochemical aspects in the pleurodele and the axolotl].	in both species, the primary mesodermal blastema of the forelimb bud derives from a regional proliferation of somatopleural cells under the ectoderm. a cellular sheet of somitic origin invades the limb blastema early. morphological and histochemical changes suggest the establishment of early ecto-mesodermal interactions in the young limb bud.	1975	808278
the effect of healing time on the proximodistal organization of double-half forelimb regenerates in the axolotl, ambystoma mexicanum.		1978	751844
neurotrophic control of the cell cycle during amphibian limb regeneration.	it is shown here that amputated and denervated limbs of larval axolotls dedifferentiate and a proportion of the cells released undergo dna synthesis and mitosis. when the limb is denervated prior to amputation fewer cells go through the cell cycle, implying the existence of a pool of trophic factor in the limb. recent work has demonstrated that denervated blastemal cells accumulate in the g1 phase of the cycle. these results strongly argue against the theory that the trophic factor controls the ...	1978	744947
mesodermalization of amphibian gastrula ectoderm in transfilter experiments.	transfilter experiments were carried out with competent gastrula ectoderm of triturus vulgaris and ambystoma mexicanum as the reacting materials and blastoporal lip, alcohol-treated bone marrow and archenteron roof as the inducing materials, it was shown that a mesodermal inducing substance is able to penetrate nuclepore filters of different pore sizes (3.0, 1.0, 0.4, 0.2 micrometer). the degree of mesodermal differentiations depends on the reacting materials, the inductors and the filters which ...	1978	732366
the differentiation-pattern in dependence of the proportion between inducing and induced cells studied on gastrula-ectoderm of ambystoma mexicanum.	the dependence of the differentiation-pattern of competent amphibian ectoderm on the proportion of inducing and induced material was studied. to do so different masses of licl-treated tissue were combined with a constant mass of untreated material. licl-treated isolates corresponding in size with the treated portions in the combinations served as controls. the experiments seem to show at least three factors responsible for the differentiation-pattern of the combinations: the number of inducing c ...	1978	732361
regulation of the mauthner cell following unilateral rotation of the prospective hindbrain in axolotl (ambystoma mexicanum) neurulae.		1978	679039
studies on the effects of bleaching amphibian rod pigments. iv. photoresponses recorded intracellularly from axolotl red rods following bleaching flashes.		1978	668824
studies on the effects of bleaching amphibian rod pigments in situ. iii. linear dichroism in axolotl red rods before and during bleaching.		1978	668823
regeneration of mirror symmetrical limbs in the axolotl.	mirrow symmetrical, double posterior limbs were produced by two types of operations on tailbud embryos of the axolotl, ambystoma mexicanum. when the limbs had grown to maturity, they were amputated and a study was made of the structures which regenerated in their place. the majority of the regenerates were also reduplicated, although a significant minority showed other types of symmetry. reduplicate symmetry was often conserved following several amputations, but the number of skeletal elements p ...	1978	667926
the failure of double-half forelimbs to undergo distal transformation following amputation in the axolotl, ambystoma mexicanum.	although capable of initiating early regenerative responses, axolotl forelimb stumps which are composed of double-half limb tissues fail to undergo the events that normally lead to the replacement of missing parts. in the present study, the posterior halves of right forelimbs were exchanged with the anterior halves of left forelimbs, or the dorsal halves of right forelimbs were exchanged with the ventral halves of left forelimbs. forelimbs were amputated through the graft region 30 days after gr ...	1978	660138
developmental studies on an apparent cell-lethal mutant gene-ut-in the mexican axolotl, ambystoma mexicanum.	the discovery of a new mutant gene in stocks of the mexican axolotl derived from breeding stock of the hubrecht laboratory, the netherlands, is described. the gene appears to be a simple recessive and displays complete penetrance. ut/ut larvae develop normally through hatching, but begin to lag in growth and display characteristics defects in gill and limb formation shortly thereafter. the results of parabiosis of normal and mutant embryos, as well as embryological transplants of mutant limb and ...	1978	657276
cinematographical study of cell migration in the opened gastrula of ambystoma mexicanum.	the migration of inner marginal cells was studied in the ambystoma gastrula, using scanning electron micrography and time-lapse cinemicrography. scanning electron micrographs of gastrulae which were fixed while intact revealed that the migrating cells have flattened lamellipodia at their anterior end and a rounded cell body, which can sometimes be seen to be attached to a neighbouring cell by a slender posterior process. films of opened gastrulae showed actively moving cells, with the same featu ...	1978	650142
interaction between foreign and regenerating axons in axolotl muscle.		1978	647386
[cell proliferation study at various stages of gastrulation in axolotl embryos].	a study of cell proliferation in different regions of axolotl embryos has shown a rather uniform distribution of the s phase and mitotic indices in the animal half of the early and midgastrulae. the dorsal blastoporal lip is characterized by a very low s phase index as compared with the other regions of the embryo.	1978	643249
supernumerary limbs in the axolotl.		1978	643082
studies on the effects of bleaching amphibian rod pigments in situ ii. the kinetics of the slow bleaching reactions in axolotl red rods.		1978	639884
studies on the effects of bleaching amphibian rod pigments in situ. i. the absorbance spectra of axolotl and tiger salamander rhodopsin and porphyropsin.		1978	639883
the pattern of innervation of a polyneural muscle: axolotl iliotibialis.	the pattern of innervation on individual iliotibialis muscle fibres from axolotl (ambystoma mexicanum) has been investigated histologically and electrophysiologically. these polyneural fibres were found to be innervated on average at five end plate sites. the sites were distributed irregularly along each fibre. average end plate length was found to be approximately 70 micrometer. most end plates were separated by less than 1000 micrometer; 26% by less than 150 micrometer; the average separation ...	1978	627010
experimental studies on two mutant genes, r and x, in the mexican axolotl (ambystoma mexicanum).		1978	620874
the occurrence of supernumerary limbs following blastemal transplantation in the regenerating forelimb of the axolotl, ambystoma mexicanum.		1978	620870
[differentiation behavior of the mesodermal germinal sone of differently old pregastrulation stages of ambystoma mexicanum. cultivation of untreated and lithium-treated isolates].	isolates from the dorsal, lateral and ventral area of the marginal zone are showing differentiation capacities already in the stage of early morula. the composition of the differentiation pattern alters: ecto- and mesodermal tissues are realized until the late morula. beyond these, endodermal structures are visible with the stage of early blastula. after a mild li treatment of the isolates the differentiation pattern of the marginal zone shows significant modifications. ectodermal organs are reg ...	1977	614737
antibody-dependent cellular cytotoxicity in poikilotherms.	51cr-chromate labelled chicken red blood cells, treated with rabbit (anti-chicken red blood cell) serum, are lysed in vitro, in the absence of complement, by spleen cells from xenopus laevis, ambystoma mexicanum or lacerta viridis. optimal conditions for lysis by xenopus spleen cells were determined. the phenomenon seems homologous with antibody-dependent cellular cytotoxicity (adcc) mediated by mammalian or avian k cells. the phylogenetic significance of the finding is discussed.	1977	612470
a lethal mutant gene in the mexican axolotl.	gene ph was discovered in a wild-type axolotl male received from mexico city. larvae homozygous for this gene become recognizable by their lighter color at hatching or shortly after. the development of their forelimbs is retarded, and all limbs are of subnormal length because of the reduction in length of their long bones. many affected larvae die without feeding, and very few survive beyond their third month. at death, older larvae usually show abnormalities of the renal system, edema, ascites, ...	2006	608947
artificial neural induction in amphibia. i. sandwich explants.	1. embryonic tissues (ectoderm, neural plate) of ambystoma mexicanum and tritus were killed with hot water and implanted into ectoderm sandwiches. they induced the ectoderm to form neural tissue, lentoids and unspecialized epidermis. neural tissue always showed retina character. egg pigment was eliminated and gathered at the outer retinal surface or in the centre of rosettes. neural crest cells like mesenchyme or melanophores were completely lacking, retinal pigment did not develop. 2. the thus ...	1977	603082
axolotl stretch reflex [proceedings].		1977	599458
the role of schwann cells in paradoxical regeneration in the axolotl.	the experiments described here examine further the conditions under which paradoxical regeneration occurs and provide support for the hypothesis that a proximal migration of schwann cells is responsible for the phenomenon. when only the hand is shielded from irradiation and the limb is denervated, amputation through the forearm or upper arm sometimes results in regeneration. the effects of variation in the time interval between denervation and amputation, the level of amputation and the method a ...	1977	591863
a natural heterohaemagglutinin in xenopus laevis serum.	in most adult xenopus laevis the serum contains a 'natural' factor capable of lysing the erythrocytes from a wide variety of amniote species. the factor has no effect on the erythrocytes of another amphibian, ambystoma mexicanum, nor will serum from one animal lyse red cells from another xenopus individual. no lysing factor was present in the serum of larval (tadpole) xenopus. heating of xenopus serum to 56 degrees for 30 min, absorption of the serum with zymosan or inulin, or removal of calcium ...	1978	580428
dna synthesis after polyspermic fertilization in the axolotl.	cytological and autoradiographic studies were done to investigate the cytoplasmic control of dna synthesis under conditions of physiological polyspermy. the dna synthetic phases of the egg, principal sperm and accessory sperm nucleic were determined and correlated with nuclear morphology and develpmental fate. results show that accessory sperm nuclei undergo morphological transition to pronuclei. their dna synthetic phase is the same as that of the principal sperm nucleus. hence accessory sperm ...	1979	574896
evidence for a dna ligase change related to early cleavage in axolotl egg.	a definite change in the forms of dna ligase appears when the axolotl egg enters cleavage. sucrose gradient and phosphocellulose chromatography show that the a 6s form of dna ligase exists before division, i.e. in unfertilised and fertilised egg, and a 8.2s form is present at the first division. n-ethylmaleimide sensitivity and heat stability are different for the two forms. the possible significance of this early change is discussed.	1979	574805
preferential expression of the maternal allele for alcohol dehydrogenase (adh) in the amphibian hybrid ambystoma mexicanum (axolotl) x ambystoma texanum.		1977	561728
microtubule proteins in axolotl eggs and developing embryos.		1977	559603
development of the sympathetic system in the mexican axolotl, ambystoma mexicanum.		1977	557011
the formation of muscles in regenerating limbs of the newt after denervation of the blastema.	the purpose of this experiment was to examine the relationship, if any, between nerve fibers and the formation of muscle pattern in the regenerating amphibian limb. during embryogenesis, nerve fibers grow into the limb bud at the time when the common muscle blastemas subdivide into individual muscle primordia, whereas in regeneration nerve fibers are always present. in order to learn whether or not the muscle pattern could be laid down in the absence of nerves we amputated 58 limbs of newts (not ...	1979	528874
positional information in the forelimb of the axolotl: experiments with double-half tissues.		1979	527764
embryo surface morphology during post-gastrula development of the frog, bombina orientalis, as revealed by scanning electron microscopy.	to further study the morphology of the developing amphibian embryo, and to provide a basis for the characterization of abnormal embryogenesis, surface features of the bombina orientalis embryo during post-gastrula development were examined with the scanning electron microscope. ciliated cells similar to those reported for rama pipiens and ambystoma mexicanum were observed in the epidermis. epidermal secretory cells displaying large numbers of exocytotis apertures become prominent at the early ta ...	1996	500492
steroidogenesis in axolotl testis. histochemistry of two major enzymes related to cell type, spermatogenesis, and substrate.		1979	499762