Factors Responsible for the Abnormal Development of Embryos Obtained by Nuclear Transplantation in Xenopus laevis

Development ◽  
1960 ◽  
Vol 8 (3) ◽  
pp. 327-340
Author(s):  
J. B. Gurdon
Keyword(s):  
Xenopus Laevis ◽  
Embryo Development ◽  
Normal Development ◽  
Nuclear Transplantation ◽  
Abnormal Development ◽  
Donor Nucleus ◽  
Innate Capacity

In Xenopus the embryos derived from nuclear transplantation often develop abnormally. These abnormalities must be due to the limited potentiality for development of either the donor nucleus or the egg cytoplasm; this limited potentiality will in turn be due to technical damage during transplantation or to the innate condition of the nucleus or cytoplasm before the experiment. The extent to which these technical and innate factors are responsible for abnormalities of transplant-embryo development has been analysed by considering the effect of each factor in turn. Nuclei from early donor stages have been used, since these nuclei are believed to be undifferentiated (see p. 338) and therefore to have the innate capacity for entirely normal development. The effects of other factors have been investigated by experiments in which each factor is varied in different ways. Any correlation between variations in one factor and the resulting proportion of abnormal transplant-embryos is then recorded.

TERATOGENIK EKSTRAK ETANOL UWI BANGGAI UNGU (Dioscorea alata L.) PADA MENCIT BETINA (Mus musculus)

2020 ◽  
Vol 5 (2) ◽  
pp. 309-318
Author(s):  
Ihwan Ihwan ◽  
◽  
Rahmatia Rahmatia ◽  
Khildah Khaerati ◽  
Keyword(s):  
Treatment Group ◽  
Embryo Development ◽  
Mus Musculus ◽  
Birth Defect ◽  
Abnormal Development ◽  
Dioscorea Alata ◽  
Treatment Groups ◽  
Study Results ◽  
Pregnant Mice ◽  
Ethanol Extracts

Teratogenic is an abnormal development on embryo and is the cause of congenital defect or birth defect. This study aims to determine the effect of the addition of Dioscorea alata L. ethanol extracts to the embryo development on pregnant mice whose given orally to 24 mice which divided to 4 treatment groups, they are the normal group (NG) with NaCMC 0.5%; 28 mg/KgBB treatment group; 35 mg/KgBB; 42 mg/Kg BB. The addition of Dioscorea alata L ethanol extracts was done on the sixth day until the 15th day of pregnancy. On the 18th day of pregnancy, Laparaktomi was done to the pregnant mice and the embryo was taken out of the uterus. The observation was done to the fetus numbers, weight weighing of the fetus's body, dan length measurement of the fetus's body. Another observation is the observation of the external organ defect of the embryo. The study results that the addition of Dioscorea alata L ethanol extracts with various doses have no significant effect (P>0.5) to the mice external fetus development. On the examination of the fetus, we can conclude that Dioscorea alata L ethanol extracts don’t give any effect that may cause the defect of the fetus’ external organ.

Fission yeast tmsl protein abrogates normal development in Xenopus laevis embryos

1995 ◽  
Vol 204 (3) ◽  
pp. 198-202 ◽  
Author(s):  
Peter Wagner ◽  
Michael Hoever ◽  
Katrin Appel ◽  
Walter Kn�chel ◽  
Mathias Montenarh
Keyword(s):  
Xenopus Laevis ◽  
Fission Yeast ◽  
Normal Development ◽  
Xenopus Laevis Embryos

Reversible arrest of Artemia development by cadmium

1986 ◽  
Vol 64 (8) ◽  
pp. 1633-1641 ◽  
Author(s):  
Parvaneh Rafiee ◽  
Christopher O. Matthews ◽  
Joseph C. Bagshaw ◽  
Thomas H. MacRae
Keyword(s):  
Normal Development ◽  
Developmental Process ◽  
Inhibitory Effect ◽  
Microtubule Assembly ◽  
Abnormal Development ◽  
Dependent Manner ◽  
Physiological Changes ◽  
Molecular Aspects ◽  
Reduced Rate ◽  
Dose Dependent

Under normal conditions, an encysted Artemia embryo undergoes a developmental process that culminates in the gradual, uninterrupted emergence of the prenauplius from the cyst. The hatching membrane surrounding the emerged organism is then ruptured, usually beginning at the posterior end, and a motile nauplius is released. We have observed this process microscopically in the presence and absence of cadmium and report that cadmium disrupts Artemia development in a dose–dependent manner. At 0.1 μM, cadmium slows emergence but nauplii eventually resume rellatively normal development. Emergence and hatching are either delayed considerably or almost entirely prevented at 1 μM cadmium. Cadmium at 10 μM, completely arrests emergence but development continues at a reduced rate, eventually resulting in hatching of some organisms without need for complete emergence. If organisms exposed to 10 μM cadmium are washed, abnormally shaped emerged forms are released and many of these eventually hatch, although in an unusual manner. Cadmium at 10 μM causes complete, rapid precipitation of purified Artemia tubulin at 0 °C but cadmium at the lower concentrations tested has no apparent inhibitory effect on microtubule assembly. Although we do not know the actual cadmium–induced physiological changes that result in abnormal development of Artemia, our results indicate that we can now examine the interdependence of morphological and molecular aspects of Artemia development in a way not previously possible.

Mitotic activity of germ cells during normal development of Xenopus laevis tadpoles

Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 687-694
Author(s):  
Ken-Ichi Ijiri ◽  
Nobuo Egami
Keyword(s):  
Xenopus Laevis ◽  
Germ Cell ◽  
Mitotic Activity ◽  
Germ Cells ◽  
Regional Difference ◽  
Normal Development ◽  
Uniform Value ◽  
Interesting Conclusion ◽  
Spatio Temporal ◽  
Gland Development

Data on the spatio-temporal pattern of germ cell proliferation in Xenopus laevis tadpoles were obtained, tracing the germ cells from the cloacal position forward. This spatial pattern in germ cell distribution and its change during normal development clearly coincided with histological observations of germ gland development. By application of regression lines to the analysis of this complex pattern, an interesting conclusion about the mitotic activity of germ cells was suggested. While the mitotic activity of germ cells before sexual differentiation shows a regional difference along the germ-cell-containing ridge (GCCR), the doubling time of sexually differentiated gonia seems to show a uniform value over the whole GCCR

scholarly journals Peculiarities of in vitro parthenogenesis of unpollinated maize ovaries

2017 ◽  
Vol 6 (4) ◽  
pp. 10-13
Author(s):  
Tatyana Alekseevna Alatortseva
Keyword(s):  
Embryo Development ◽  
Nutrient Medium ◽  
Normal Development ◽  
Mother Plant ◽  
Maize Line ◽  
Mineral Components ◽  
Parthenogenetic Embryo ◽  
Direct Embryogenesis ◽  
Agricultural Plants

The maize line AT-1 is characterized by a hereditary predisposition to parthenogenesis. The aim of this investigation is to study parthenogenetic embryo development in the culture of unpollinated ovaries in vitro . The unpollinated ovaries were explanted in 1, 3, 5, 7, 10, 15 days after the appearance of stigmas from ears. The nutrient medium included mineral components of MS, vitamins, sucrose (9,0%), 2,4-D (2,0 mg/l), agar-agar. The structure of megagametophytes at the time of inoculation of the ovaries and on the 3rd, 7th, 14th, 21th, 28th day of cultivation was studied. The first divisions of unfertilized egg cells were observed on the 5th-7th day after appearance of stigmas from ears, independently from whether all this time the ovaries were on the mother plant or they were inoculated into the nutrient medium. The formation of the autonomous abnormal endosperm in some cultivated ovaries was detected. The abnormal endosperm disturbed normal development of the proembryo. As a rule, the ovaries with embryo and endosperm degenerated. In the absence of endosperm, the morphogenesis of parthenogenetic proembryos was carried out in one of two directions in vitro : 1) development of plants by direct embryogenesis; 2) regeneration of plants from numerous embryoids, raised on the surface of globular proembryos. The second direction was prevailed. The culture of unpollinated ovaries can be a promising method of mass haploid regenerants not only in maize, but also in other types of agricultural plants.

Ploidy, pigment patterns and species specific antigenicity in interspecific nuclear transplantations in newts

Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 319-330
Author(s):  
F. Sládeček ◽  
A. Romanovský
Keyword(s):  
Xenopus Laevis ◽  
Functional Activity ◽  
Nuclear Transplantation ◽  
Skin Grafts ◽  
Species Specific ◽  
Transplantation Antigens ◽  
Transplantation Experiments ◽  
Pigment Patterns

It was shown by Simnett (1964) that in Xenopus laevis skin grafts in adult frogs between members of the same nuclear clone were tolerated in the same way as autografts, but in skin grafts made between individuals belonging to different nuclear clones a homograft rejection occurred. The nucleus is therefore responsible for the synthesis of specific transplantation antigens. It seemed to us useful to investigate the species-specific antigenicity of animals derived from eggs transplanted with foreign nuclei in correlation with their ploidy and with the development of their species-specific pigment patterns, as a proof of functional activity of transplanted nuclei. For this purpose we used two species of Triturus, T. vulgaris and T. alpestris, because of earlier studies carried out in our laboratory on the pigmentation of their hybrids (Romanovský & Ŝtefanová, 960; Mazáková-Štefanová, 1965) and on their species-specific antigenicity (Romanovský, 1962 a, b), in spite of the known difficulties and limitations of nuclear transplantation experiments in these species (Lehman, 1955; Sládeček & Mazáková-Štefanová, 1964, 1965).

Nuclear transplantation of male primordial germ cells in the mouse

Development ◽  
1989 ◽  
Vol 107 (2) ◽  
pp. 407-411 ◽  
Author(s):  
Y. Tsunoda ◽  
T. Tokunaga ◽  
H. Imai ◽  
T. Uchida
Keyword(s):  
Germ Cells ◽  
Inner Cell Mass ◽  
Primordial Germ Cells ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Nuclear Transplantation ◽  
Embryonic Genome ◽  
Donor Nucleus ◽  
Implantation Sites ◽  
Genome Activation

We examined the developmental ability of enucleated eggs receiving embryonic nuclei and male primordial germ cells (PGCs) in the mouse. Reconstituted eggs developed into the blastocyst stage only when an earlier 2-cell nucleus was transplanted (36%) but very rarely if the donor nucleus was derived from a later 2-cell, 8-cell, or inner cell mass of a blastocyst (0–3%). 54–100%, 11–67%, 6–43% and 6–20% of enucleated eggs receiving male PGCs developed to 2-cell, 4-cell, 8-cell and blastocyst stage, respectively, in culture. The overall success rate when taking into account the total number of attempts at introducing germ cells was actually 0–6%. Live fetuses were not obtained after transfer of reconstituted eggs to recipients, although implantation sites were observed. The developmental ability of reconstituted eggs in relation to embryonic genome activation and genomic imprinting is discussed.

Cardiac output in Xenopus laevis tadpoles during development and in response to an adenosine agonist

1996 ◽  
Vol 270 (5) ◽  
pp. R997-R1004
Author(s):  
Y. Y. Tang ◽  
C. M. Rovainen
Keyword(s):  
Cardiac Output ◽  
Xenopus Laevis ◽  
Cardiac Cycle ◽  
Normal Development ◽  
Volume Overload ◽  
Adenosine Agonist ◽  
Video Frames ◽  
Blood Pressures ◽  
Aquarium Water ◽  
Accelerated Growth

We test the hypothesis that the heart and arteries enlarge with increased cardiac output (CO) during development and volume overload. Transparent albino tadpoles of Xenopus laevis at stages 43-50 were anesthetized in 0.3-0.5 mM benzocaine. Areas and radii [maximum and minimum radius (Rmax and Rmin, respectively)] of the ventricle were measured in digitized video frames during the cardiac cycle. Stroke volume (SV) and CO were calculated from Rmax and Rmin. Maximal velocities of 3.4-microns fluorescent beads were measured in the aortic arches. Arterial pressure was estimated by the Landis method. During normal development, the radii of the ventricle and aortic arch diameters increased with lengths of tadpoles, and SV (0.7 microliters/g) and CO (70 microliters.g-1.min-1) with wet weights. Volume overload was induced by a vasodilatory adenosine agonist 5'-N-ethylcarboxamidoadenosine (NECA) in the aquarium water. Acute (0.5-4 h) NECA significantly increased Rmax and heart rate. Chronic (> 1 wk) NECA significantly increased both Rmax and Rmin. SV and CO increased more than two times, blood pressures decreased, and specific vascular conductances increased more than five times. It is concluded that NECA increases CO in Xenopus tadpoles through a combination of increased filling and accelerated growth.

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