Morphogenetic Sequences Research Articles

Prenatal developmental sequences of the esophageal epithelium in the New Zealand white rabbits: Light and electron microscopic analysis.

Several morphogenetic sequences occur during esophageal development and birth defects occur due to defects in foregut morphogenesis. This work aimed to record the cellular events in the morphogenesis of rabbits' esophageal epithelium. On the 16th day of gestation, the esophageal epithelium varied from stratified ciliated columnar to stratified squamous type. The surface epithelium presented mucous cells with mucigen granules of various sizes occupying their supranuclear cytoplasm. Cytoplasmic vacuolation was evident in all layers of the esophageal epithelium at this age. On the 18th gestational day, some light cells could be detected in the middle portion of the epithelium, while others occupied the whole epithelial length. On the 21st day, mucous cells are more frequently observed at the apical esophageal part as well as at the surface epithelium. Numerous elongated dark cells could be distinguished embedded between the basal cells. On the 24th gestational day the number of the mucous cells reached its peak. Reaching the 30th gestational day, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased. Collectively, detection of surface mucous and dark cells together with the non-cornified surface in some regions of the rabbit esophageal epithelium at the end of gestation ensure a postnatal development to reach the adult epithelium essential to sustain the passage of the harsh raw food. Future immunohistochemical studies are recommended to investigate the components of secretions in mucous cells and functional studies to highlight the dark cells significance. RESEARCH HIGHLIGHTS: Esophageal epithelium of fetal rabbit was analyzed by light and transmission microscopy. Surface epithelium presented mucous cells with mucigen granules of various sizes. They reached their maximum number on 24th day then decreased. On the 16th day, cytoplasmic vacuolation was evident in all epithelial layers. On the 21st day, numerous elongated dark cells could be distinguished embedded between the basal cells. Before birth, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased.

Formes d’ érosion prémégalithiques et postmégalithiques sur les menhirs de calcaire du causse Méjean (Lozère)

Les mégalithes portent des marques d’érosion antérieures à leur construction, lorsqu’ils proviennent de blocs rocheux initialement situés à l’affleurement, et des marques d’érosion postérieures à leur élévation, organisées à partir de leur sommet. Les premières sont des formes prémégalithiques (vasques latérales, rainures,...) et renseignent sur l’origine des blocs utilisés comme mégalithes. Les secondes sont des formes postmégalithiques (vasques sommitales, sillons, lapiés...) et renseignent sur les modalités et sur la vitesse de l’érosion au cours des derniers millénaires, l’édification du monument servant en l’occurrence de marqueur chronologique. Le causse Méjean comprend des menhirs de calcaire dont les marques d’érosion ont été examinées selon une méthode appliquée par ailleurs sur des mégalithes de granite ou de schiste. Cette méthode comprend quatre niveaux d’analyse relatifs à la forme générale des blocs utilisés comme menhirs, à la morphologie des pans (notamment des faces d’affleurement et des faces d’arrachement), à la caractérisation des formes prémégalithiques ou postmégalithiques et aux états de surface des menhirs. Elle s’applique ici à des formes d’origine karstique ou périglaciaire. Elle contribue à illustrer l’intérêt d’une double approche, archéologique et géomorphologique dans l’étude des mégalithes.

Knowledge of Making Life: Design Pattern for Regenerative-Adaptive Design

<p>An astonishing intense fascination is under way in the design sciences, where the words of ‘living structures’ and ‘adaptive’ are being linked with ‘technology. In part fuelled by the emergence of the Anthropocene discourse, these words are inspiring authoritative new insights into the workings of wild nature, humanity’s position and responsibility to planet Earth, and is being articulated through the rapidly increasing science of pattern theory. The new terminology is provoking the design sciences to seriously consider technologically-informed innovation in design and new possibilities including living technology, morphogenetic sequences, self-organisation, generative codes, biophilia, biomimetics and regenerative-adaptive design, opening the doors to a new era in ecology-informed design. The idea of design as an adaptive and transformation process, is at the core of the whole systems theory pioneered by Alexander in <em>A Pattern Language</em> (1977) and <em>The Nature of Order</em> (2001-2005). Alexander positioned this hypothesis in generative codes supported by morphogenetic sequences. Drawing upon Alexander’s <em>The Nature of Order</em> (2001-2005), this paper advances a regenerative-adaptive design theory (Roӧs, 2016), towards a holistic integrated design method that incorporates the principles of regenerative design with an adaptive pattern language that re-establishes human wholeness with nature and offers relevant strategies towards resilience; in essence creating a living technology. </p>

Site‐specific interactions of neurotrophin‐3 and fibroblast growth factor (FGF2) in the embryonic development of the mouse cochlear nucleus

Neurotrophins and FGF2 contribute to formation of the cochlea, but their roles in cochlear nucleus development are unknown. The effects of these factors may differ in the cochlea and cochlear nucleus, which may influence each other's development. It is important to analyze the effects of these factors on cellular structures at well-defined steps in the normal morphogenetic sequence. The present study used immunohistochemistry to localize factors in situ and to test hypotheses about their roles in an in vitro model. Specific antibody staining revealed that TrkC, the NT3 receptor, is present in neural precursors prior to embryonic day E11 until after birth. NT3 appeared in precursor cells during migration (E13-E15) and disappeared at birth. TrkC and NT3 occurred in the same structures, including growing axons, terminals, and their synaptic targets. Thus, NT3 tracks the migration routes and the morphogenetic sequences within a window defined by TrkC. In vitro, the cochlear nucleus anlage was explanted from E11 embryos. Cultures were divided into groups fed with defined medium, with or without FGF2, BDNF, and NT3 supplements, alone or in combinations, for 7 days. When neuroblasts migrated and differentiated, immunostaining was used for locating NT3 and TrkC in the morphogenetic sequence, bromodeoxyuridine for proliferation, and synaptic vesicle protein for synaptogenesis. By time-lapse imaging and quantitative measures, the results support the hypothesis that FGF2 promotes proliferation and migration. NT3 interacts with FGF2 and BDNF to promote neurite outgrowth, fasciculation, and synapse formation. Factors and receptors localize to the structural sites undergoing critical changes.

Biotinidase reveals the morphogenetic sequence in cochlea and cochlear nucleus of mice

Hearing loss affects children with biotinidase deficiency, an inherited metabolic disorder in the recycling of biotin. The deficit appears shortly after birth during development of the auditory system. Using a mouse model, we sought to discover where and when biotinidase is expressed in the normal development of the cochlea and cochlear nucleus. In the process, we reconstructed the normal morphogenetic sequences of the constituent cells. Immunolabeling for biotinidase was localized to neurons and other cells of the adult and immature mouse, including the embryonic precursors of these regions dating from the stage of the otocyst. Its distribution was compared to the particular morphological changes occurring at each developmental stage. Biotinidase was localized in cells and their processes at the critical stages in their proliferation, migration, structural differentiation, and innervation, covering the entire span of their development. The prevalence of immunostaining peaked in the adult animal, including hair cells and ganglion cells of the cochlea and neurons of the cochlear nucleus. The findings suggest that biotinidase plays a role in the normal development of the auditory system. Besides the pattern of localization of biotinidase, this study provides the first systematic account of each developmental stage in a mammalian auditory system.

Calcretes in semi-arid alluvial systems: formative pathways and sinks

Late Quaternary deposits in Gujarat, western India show an abundant development of calcretes. Three major sinks of carbonate in the alluvial deposits are recognized: (1) groundwater calcretes, (2) pedogenic calcretes, and (3) calcrete conglomerates. Groundwater calcretes originate from carbonate-saturated waters travelling preferentially along stratification planes. Pedogenic calcretes form through soil-forming processes typically in extra-channel areas. Calcrete conglomerates occur as ribbons, sheets and lenses due to the reworking of both pedogenic as well as groundwater calcretes. As a result a pathway of calcretization develops that has the route: groundwater calcrete to pedogenic calcrete to calcrete-conglomerate. The formation of pedogenic calcretes over sediments containing groundwater calcretes demonstrates that (1) apart from aeolian dust, river waters are also a major source of carbonate, and (2) pedogenic carbonates may attain large sizes at accelerated rates due to the presence of pre-existing groundwater calcretes. Consequently, the maturity of a soil may be overestimated if determined by following established morphogenetic sequences.

Histology, histochemistry, tumor and serum markers in gastrointestinal tract cancer.

Integration of morphologic and molecular information is being pursued as a result of more extensive use of in situ hybridization techniques. Oncogenes, gene products, and viral genomes involved in the genesis and progression of gastrointestinal tumors have been located in specific histotypes or tumor sectors. The main advances in this area relate to cell-matrix interactions and the biologic mechanisms of tumor invasion. Some aspects of the morphogenetic sequences of gastric and colorectal adenocarcinomas and hepatocellular carcinoma have been elucidated. Studies of DNA ploidy have furnished results consonant with carcinogenesis models envisaging sequential genome alterations due to genetic instability of the transformed cell. The prognostic role of DNA content in gastrointestinal tumors, however, has not been unequivocally established. Research on tumor markers has been directed toward the tissue expression and distribution of apomucins with different molecular structures. Evaluation of tumor markers in body fluids has proved inadequate for the early detection and screening of gastrointestinal neoplasia. Some interesting results have been reported with regard to the monitoring of gastric and colorectal carcinomas by means of serum tumor markers.

Morphogenetic sequences of the rooting process after in vitro culture or Agrobacterium rhizogenes inoculation

Abstract After a brief review dealing with the factors inducing adventitious rhizogenesis, the morphogenetic patterns of the rooting process induced by in vitro culture or after Agrobacterium rhizogenes inoculations are described. In vitro cultures of Nicotiana tabacum, Datura innoxia and Crepis capillaris leaf explants on Murashige and Skoog's medium supplemented with sucrose and IAA or NAA have been used in order to identify the target cells for direct and indirect rooting. The structural and functional features of the prerhizogenetic cells are described and the ploidy levels of both direct and indirect root meristems are examined by means of DNA microspectrophotometry. Data on the synergistic effects between auxin, sucrose and amino acids (particularly L-ornithine) for the reactivation of the prerhizogenetic cells are also given. Transformed roots from carrct root discs or pea epicotyls after Agrobacterium rhizogenes inoculation arise indirectly from cambium-like layers differentiated inside a previous...

Dikaryon Formation in Coprinus cinereus: Selection and Identification of B Factor Mutants

Mutations in the B incompatibility factor of Coprinus cinereus were obtained using two techniques. Both selected for the expression of B-controlled functions (associated with nuclear migration during dikaryon morphogenesis) in heterokaryotic mycelia where these were blocked by having identical B alleles present. The first technique selected for clamp cell fusion in a common B heterokaryon, the second selected for septum dissolution in a heterokaryon following a common B mating. Two mutants, one derived by each of the selection techniques, were studied in detail. In both, mutation was inseparable by recombination from the B locus and resulted in self-compatibility. Mutant monokaryons had uninucleate cells and intact septa. Thus, full regulatory control of morphogenesis in the mutant monokaryon was maintained. However, both mutations promoted clamp cell fusion in dikaryons formed between the mutants and monokaryons having the progenitor B allele or the mutant self allele. Therefore, mutation leads to the loss of regulation of clamp cell fusion. A combination of a B mutation and an A mutation (Amut Bmut) in the same nucleus gave a haploid mycelium which resembled a true dikaryon; thus, both the A and B morphogenetic sequences which are expressed in the dikaryon were operating. However, these dikaryons were not fertile.

“Sluggers”, a new class of morphogenetic mutants of D. discoideum

Two representatives of a newly recognized class of D. discoideum mutants termed “sluggers” are described. They display the following properties: 1. 1. The newly formed mutant aggregates invariably transform into migrating slugs even under conditions which lead their wild-type counterparts to eschew the slug mode completely and to construct fruiting bodies directly in place. Depending on environmental conditions, the mutant aggregates may remain indefinitely as migrating slugs or may, after a lapse of 10–12 h, re-enter the fruiting mode and construct normal fruiting bodies. 2. 2. The patterns of accumulation and disappearance of three enzymes previously shown to be under morphogenetic feedback control in the wild type [3] were found to be profoundly disturbed in the mutants but in ways at least partly comparable to the performance of wild-type aggregates when the latter are caused to vacillate between the alternative morphogenetic pathways of slug migration and fruit construction. 3. 3. Both morphogenetic lesions can be completely or partially suppressed by synergistic development in mixed aggregates with wild-type cells. A small proportion of wild-type cells is required. In the case of JC-2, as little as 2.5–10% was effective. Moreover, the presence of the wild type in the mixtures was not needed prior to the actual time at which the morphogenetic lesion is expressed in order to have suppressed it. 4. 4. In neither case does the initiation of the slug stage or its duration appear to be due to the over-production of NH 3 or enhanced sensitivity to it. 5. 5. The capacity of the mutant slugs to abandon that mode and initiate fruit construction is lost by removal of a diffusible metabolite(s) released into the extracellular milieu during prior morphogenesis and the capacity can be restored by its replacement. The metabolite appears to trigger fruit construction and is not required for its completion. 6. 6. The inducer accumulates during morphogenesis of both mutants and the wild type apparently in comparable amounts. It appears to be a small anionic species, dialysable and volatile at acid but not alkaline pH. Of many known compounds tested for inductive activity only sodium propionate and 2-methyl propionate were active but the concentrations required rule them out as the metabolite in question. 7. 7. Slight but significant differences in their morphogenetic sequences, patterns of enzyme accumulation and disappearance, differing sensitivities to synergistic interaction with wild type and the fruit-inducing metabolite suggest that JC-2 and JC-4, though phenotypically similar, may represent independent mutational events. However, synergistic complementation was not observed thereby raising the possibility that the morphogenetic lesions stem from the same metabolic defect.

Synapse formation in the mouse olfactory bulb. II. Morphogenesis

Serial thin sections of the mouse olfactory bulb from the fourteenth day of gestation (E14) to postnatal to 44 (P44) have been examined in order to study morphogenesis of individual synaptic junctions. At the initiation of synapse formation structures are found that resemble postsynaptic densities but are facing extracellular space or unmodified processes. Transition forms between these isolated postsynaptic densities and undoubted synapses have been found. These observations as well as quantitative studies support the hypothesis that isolated postsynaptic densities can form independently and be converted to synapses when a presynaptic specialization develops opposite them. Detailed studies of olfactory axodendritic synaptogenesis throughout the entire developmental period suggests strongly that these asymmetrical synapses pass through an immature symmetrical phase: (1) symmetrical olfactory axodendritic synapses are found in significantly higher concentration on axonal and dendritic growth cones than on more common processes; (2) the number of symmetrical synapses is correlated with the rate of formation of new synapses determined previously. The time for a recognizable symmetrical synapse to be transformed into a recognizable asymmetrical one has been calculated to be 9--10 hours. A scheme of synapse formation in the CNS has been proposed in which a post-synaptic structure forms independently followed by aggregation of pre-existing presynaptic components into a presynaptic specialization. Different morphogenetic sequences of synapse formation from region to region are attributed simply to different relative rates in the development of the postsynaptic density and the presynaptic specialization.

Morphogenetic sequences during tadpole tail regeneration

The appearance of differentiated tissue types after amputation of Rana catesbeiana tadpole tail follows a precise chronological order. Migrating epithelial cells invest the wound within 3 days. Blastemal cells accumulate under the distal epithelium in the early stages when tissue debris is cleared away, then by day 11 notochordal outgrowth and nerve axon replacement predominate in the highly vascularized blastema.Fusion of the myoblasts to form the first detectable myotubes occurs in the proximal region of the regenerate by day 14. Myogenesis proceeds distally with myotubes present under the epithelium of the distal tip of the regenerate at day 19. After day 22 further increase in tail musculature is probably due to the growth of fibers already formed. At day 22 the new muscle fibers begin to anastomose with the healed ends of the old fibers. From 35 to 48 days the major remaining difference from control tissues is the size and extent of the regenerated muscle fibers; capillaries, axons, epidermis and dermis, and neuromuscular junctions are morphologically indistinguishable from unregenerated tissues.

Regulation of sclerotium production by primary metabolites in Coprinus cinereus (= C. lagopus sensu lewis)

Aerial sclerotia of Coprinus einereus (Schaeff. ex Fr.) S. F. Gray were produced most abundantly in conditions which strongly favoured mycelial growth. With the nitrogen concentration maintained at 25 mM ammonium tartrate the number of sclerotia formed increased as the initial maltose concentration of the medium was increased, reaching a maximum at 25 mM. The length of time required for Sclerotium maturation was also minimal on media which initially contained 25 mM maltose. Changing the concentration of ammonium tartrate (in media containing 25 mM maltose) did not markedly affect the total number of Sclerotium initials which were formed but had a profound influence on sclerotial maturation. With 5 mM ammonium tartrate maturation occurred most rapidly and most completely, with 63 % of the final total sclerotial yield being matured within 7 days, and 91 % within 14 days. Higher ammonium concentrations first delayed and then prevented maturation so that at 100 mM less than 0·3% of the initials had matured within 21 days. It is suggested that the ability of ammonium ions to regulate Sclerotium maturation can be correlated with the ability of the sporophore to excrete ammonia into the medium so as to provide a mechanism for sequencing the two pathways. While sporophores are developing the ammonium concentration will be maintained at a level which prevents sclerotial maturation, thus avoiding competition for metabolities between the two morphogenetic sequences.

Clay Mineralogy, Physical, and Chemical Properties of Some Soils in Arid Regions of Iran

AbstractCoarse, medium, and fine‐textured soils were studied in three different arid regions of Iran, namely Gazvin, Karaj, and Kooshkak alluvial plains, respectively. Six representative pedons including 33 samples were tested.X‐ray analyses indicated the clay mineral components of soils consist of some discrete vermiculite, chlorite, clay mica (illite), kaolinite, and interstratified clay mica‐vermiculite or chlorite.Quantitatively, vermiculite and clay mica are the major clay mineral components in these soils. The average vermiculite contents of coarse, medium, and fine‐textured soils are calculated as 41.7, 41.4, 42.4%; clay mica contents are 26.3, 38.0, and 20.0%, respectively. The amount of clay mica decreases significantly with depth in most of the soils studied.Physico‐chemical determinations revealed the soils are calcareous throughout and the carbonates increase from coarse‐ to fine‐textured soils. The morphogenetic sequences of carbonate accumulation are divided into three morphogenetypes. Most organic matter contents are < 1%. They decrease with depth but increase from coarse‐ to fine‐textured soils.Soils with poor structural development contain > 20% CaCO3, and have considerable amounts of vermiculite but lower amounts of clay mica. The slight accumulation of silt, clay, and carbonates at the surface of some soils may indicate the influence of atmospheric addition in the genesis of the soils studied. Two of the soils are classified Typic Camborthids, two of them Xerollic Camborthids, and the other two, Xerollic Calciorthids.

Morphogenesis of the fetal membranes and placenta of the black bear, Ursus americanus (Pallas).

AbstractKnowledge of placentation in bears has been limited to analysis of a single shed placenta of the European brown bear. It was shown that the mature allantoic placenta is discoidal, endotheliochorial, provided with a circular marginal hematoma, and that the allantoic sac is large and permanent. The present study, based on a small series of conceptuses younger than any previously examined, provides new details concerning implantation and the morphogenesis of the fetal membranes, placenta and paraplacental organs. Implantation in the black bear is central and superficial; the orientation of the embryonic disc is antimesometrial. Amniogenesis and chorion formation are almost certainly accomplished by folding. The decidual reaction is minimal. As in other carnivores the yolk sac is prominent early, but progressively declines. A well‐developed choriovitelline placenta is formed early, but is eliminated before the limb bud stage. The bilaminar omphalopleure persists only slightly beyond the limb bud stage. The allantois, however, is extensive and permanent. Initially, the allantoic placenta is cup‐shaped but eventually flattens out to form the discoidal placenta. It is lobuliform and endotheliochorial, and probably a marked attenuation of the interhemal membrane occurs in later stages. The marginal hematoma, which is completed before the limb bud stage, is formed by enlargement and coalescence of separate extravasations, and apparently remains fully functional to term. Overall, morphogenetic sequences and relationships in bears more nearly resemble those of the dog than of other carnivores.

Intrapulmonary stromal mesothelioma

Summary There is an entity of solitary benign spindle cell mesothelioma which grows in relation to bronchi within the lung, but is unrelated to the pleura. Its similarity to growths reported as "fibrosarcoma of bronchus" is pointed out. There are morphogenetic sequences in embryonic pulmonary development which could account for a mesothelial tumor arising without pleural contact. A designation of paramesathelioma or stromal mesothelioma is suggested as more appropriate than "fibrous" mesothelioma for those mesothelial tumors which differentiate as spindle cell growths similar to ovarian fibrothecomas or are derived from submesothelial mesenchyme. Doctors Alfred Goldman, Edward Shapiro, Maurice Hyman, and Marvin Harris permitted use of the clinical material.