Isozymes and morphology of five amphibian hybrid embryo combinations which develop beyond gastrulation

Hybrid embryos were produced by inseminating R. clamitans or R. septentrionalis eggs with R. catesbeiana, R. pipiens, or R. septentrionalis sperm. They were examined for morphological development and for paternal enzyme expression. One of the hybrid combinations was viable while the others arrested after neurulation but before feeding. Gastrulation and neurulation did not guarantee further tissue differentiation nor even a well-formed neural tube. The internal and external morphology of an arrested hybrid was characteristic for that particular egg–sperm combination. Regardless of the degree of morphological development, expression of a paternal gene for lactate dehydrogenase (LDH) was detected in three of the hybrid combinations when control embryos were at stages 19 or 20. Paternal forms of three other enzymes were detected in some of the hybrids after control stage 20.In addition, a polymorphism in LDH was found in R. clamitans. As determined genetically, there are at least three alleles of the B gene of LDH in the R. clamitans population.

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Proliferating ability, morphological development and acetylcholinesterase activity of the neural tube cells in early chick embryos

Histochemistry ◽

10.1007/bf00543953 ◽

1982 ◽

Vol 76 (3) ◽

pp. 303-314 ◽

Cited By ~ 28

Author(s):

A. Miki ◽

H. Mizoguti

Keyword(s):

Neural Tube ◽

Acetylcholinesterase Activity ◽

Morphological Development ◽

Chick Embryos

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The epithelium of the dorsal marginal zone of Xenopus has organizer properties

Development ◽

10.1242/dev.116.4.887 ◽

1992 ◽

Vol 116 (4) ◽

pp. 887-899 ◽

Cited By ~ 14

Author(s):

J. Shih ◽

R. Keller

Keyword(s):

Neural Tube ◽

Marginal Zone ◽

Tissue Differentiation ◽

Host Cells ◽

Mesoderm Induction ◽

Epithelial Layer ◽

Spemann Organizer ◽

Deep Region ◽

Early Gastrula ◽

Axial Development

We have investigated the properties of the epithelial layer of the dorsal marginal zone (DMZ) of the Xenopus laevis early gastrula and found that it has inductive properties similar to those of the entire Spemann organizer. When grafts of the epithelial layer of the DMZ of early gastrulae labelled with fluorescein dextran were transplanted to the ventral sides of unlabelled host embryos, they induced secondary axes composed of notochord, somites and posterior neural tube. The organizer epithelium rescued embryos ventralized by UV irradiation, inducing notochord, somites and posterior neural tube in these embryos, while over 90% of ventralized controls showed no such structures. Combinations of organizer epithelium and ventral marginal zone (VMZ) in explants of the early gastrula resulted in convergence, extension and differentiation of dorsal mesodermal tissues, whereas similar recombinants of nonorganizer epithelium and the VMZ did none of these things. In all cases, the axial structures forming in response to epithelial grafts were composed of labelled graft and unlabelled host cells, indicating an induction by the organizer epithelium of dorsal, axial morphogenesis and tissue differentiation among mesodermal cells that otherwise showed non-axial development. Serial sectioning and scanning electron microscopy of control grafts shows that the epithelial organizer effect occurs in the absence of contaminating deep cells adhering to the epithelial grafts. However, labelled organizer epithelium grafted to the superficial cell layer contributed cells to deep mesodermal tissues, and organizer epithelium developed into mesodermal tissues when deliberately grafted into the deep region. This shows that these prospective endodermal epithelial cells are able to contribute to mesodermal, mesenchymal tissues when they move or are moved into the deep environment. These results suggest that in normal development, the endodermal epithelium may influence some aspects of the cell motility underlying the mediolateral intercalation (see Shih, J. and Keller, R. (1992) Development 116, 901–914), as well as the tissue differentiation of mesodermal cells. These results have implications for the analysis of mesoderm induction and for analysis of variations in the differentiation and morphogenetic function of the marginal zone in different species of amphibians.

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Interrelationship among the proliferating ability, morphological development and acetylcholin-esterase activity of the neural tube cells in early chick embryos.

ACTA HISTOCHEMICA ET CYTOCHEMICA ◽

10.1267/ahc.18.85 ◽

1985 ◽

Vol 18 (1) ◽

pp. 85-96 ◽

Cited By ~ 18

Author(s):

HUMIO MIZOGUTI ◽

AKINORI MIKI

Keyword(s):

Neural Tube ◽

Esterase Activity ◽

Morphological Development ◽

Chick Embryos

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GANGGUAN PEMBENTUKAN ATAP BUMBUNG NEURAL EMBRIO MENCIT AKIBAT INDUKSI 2-ME YANG BERTEPATAN DENGAN MASA NEURULASI PRIMER

Journal of Biological Researches ◽

10.23869/bphjbr.13.2.200812 ◽

2008 ◽

Vol 13 (2) ◽

pp. 163-172

Author(s):

Eko Prihiyantoro ◽

Win Darmanto ◽

Samekto Wibowo ◽

Mammed Sagi ◽

Sri Kadarsih Soedjono

Keyword(s):

Neural Tube ◽

Pregnant Mouse ◽

The Other ◽

External Morphology ◽

Control Group ◽

Other Hand ◽

Histological Preparation ◽

Hand Control ◽

Neural Axis ◽

Pregnant Mice

The objective of this study was to determine time of neural fold fusion at dorsal mid line neural axis after treatment 2-methoxyethanol (2-ME) to pregnant mouse during neurulation period and to observe relation process of point of neural fold fusion. Mice at 08:05 gestational days treatment with 2-ME dose 7.5 mmol/kg bw on the other hand control group injected with aqua bidest. Pregnant mice at 08:12, 09:00, 09:12 was sacrificed by dislocation cervix. Embryo was collected after observe with dissecting microscope for external morphology and fixation in Bouin solution and buffer formalin for histological preparation and immunohistochemistry process. Result showed that there was failure of first point neural fold fusion at junction of perspective fore brain and mid brain. The failure of neural fold fusion was caused by increasing apoptosis neuroepithelium. There were no relation process between first point of neural fold fusion and second point or another point of fusion. Failure of first point fusion not cause failure another point of fusion. Observation at 09:12 gestational days showed that the only first point fusion was still open but formation of another part neural tube have finished.

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Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139834 ◽

1995 ◽

Vol 53 ◽

pp. 692-693

Author(s):

Yun Lu ◽

David C. Joy

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

High Resolution ◽

Morphological Development ◽

Early Hydration ◽

X Ray ◽

Blended Cements ◽

Powder Particles ◽

Chemical Wastes ◽

Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

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SEM study of the morphological effects of kinetin and zeatin on the growth and development of the apical meristem in wheat

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141263 ◽

1995 ◽

Vol 53 ◽

pp. 978-979

Author(s):

G. M. Hutchins ◽

J. S. Gardner

Keyword(s):

Growth And Development ◽

Furfuryl Alcohol ◽

Apical Meristem ◽

Plant Cells ◽

Triticum Aestivum L ◽

Morphological Development ◽

Naturally Occurring ◽

Chinese Spring Wheat ◽

Sem Study ◽

Moist Environment

Cytokinins are plant hormones that play a large and incompletely understood role in the life-cycle of plants. The goal of this study was to determine what roles cytokinins play in the morphological development of wheat. To achieve any real success in altering the development and growth of wheat, the cytokinins must be applied directly to the apical meristem, or spike of the plant. It is in this region that the plant cells are actively undergoing mitosis. Kinetin and Zeatin were the two cytokinins chosen for this experiment. Kinetin is an artificial hormone that was originally extracted from old or heated DNA. Kinetin is easily made from the reaction of adenine and furfuryl alcohol. Zeatin is a naturally occurring hormone found in corn, wheat, and many other plants.Chinese Spring Wheat (Triticum aestivum L.) was used for this experiment. Prior to planting, the seeds were germinated in a moist environment for 72 hours.

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