A Description of the Technique for Nuclear Transplantation in Xenopus laevis

Development ◽  
1960 ◽  
Vol 8 (4) ◽  
pp. 437-444
Author(s):  
T. R. Elsdale ◽  
J. B. Gurdon ◽  
M. Fischberg

A Method by which nuclei can be successfully transplanted into Amphibian eggs was first worked out by Briggs & King (1952) for the eggs of Rana pipiens. Xenopus laevis is an atypical Anuran since its eggs can be obtained throughout the year, and the resulting embryos can be reared to maturity within 12 months under laboratory conditions. Because of these advantages we have used Xenopus for nuclear transplantation experiments. Though the principle of Briggs & King's technique has been followed, differences between the eggs of Rana and Xenopus have made it necessary to modify their technique before it can be satisfactorily applied to the eggs of Xenopus. The purpose of this publication is first to give technical details of these modifications, and secondly to discuss the extent to which they might affect a direct comparison of the results of transplantations in Rana and Xenopus.

Development ◽  
1960 ◽  
Vol 8 (4) ◽  
pp. 505-526
Author(s):  
J. B. Gurdon

An important question concerning embryonic differentiation is whether the nuclei of somatic cells in different parts of an embryo come to differ genetically from each other during development. It has become possible to investigate this matter since King & Briggs (1955) have shown that nuclear transplantation is a satisfactory technique for testing the developmental potentialities of embryonic nuclei. These authors (1957, 1960) have used Rana pipiens for transplantation experiments with endoderm nuclei, and have found that these nuclei become progressively limited in their developmental capacity after the late blastula stage. This paper describes some similar experiments carried out with endoderm nuclei of Xenopus laevis. The general conclusion that nuclei change as development proceeds is confirmed; there are, however, considerable differences between Rana and Xenopus in the rate and time of onset of nuclear changes. These differences make it easier to understand the significance of nuclear differentiation during embryonic development.


Development ◽  
1967 ◽  
Vol 17 (2) ◽  
pp. 319-330
Author(s):  
F. Sládeček ◽  
A. Romanovský

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).


1960 ◽  
Vol s3-101 (55) ◽  
pp. 299-311
Author(s):  
J. B. GURDON

The effects are described of ultraviolet (u.v.) irradiation upon the eggs of Xenopus laevis. The results obtained apply to fertilized eggs and also to unfertilized eggs into which blastula nuclei have been transplanted. Eggs were irradiated up to 20 min after laying, for periods varying from 15 to 50 sec. The egg nucleus is completely inactivated by small doses of u.v. If fertilized eggs are used this gives rise to haploids, which the use of a nuclear marker has shown to be androgenetic. After irradiation the egg nucleus descends towards the centre of the egg, and comes to lie adjacent to the transplanted or sperm nucleus. At the first mitosis, however, it does not fuse but remains as a pycnotic clump in the centre of the spindle. Soon after this it disappears, without disintegrating into visible fragments. The transplanted or sperm nucleus appears to be unaffected by the irradiation and death of the egg nucleus. The egg cytoplasm does not appear to be damaged, even after doses of u.v. which are considerably more than sufficient to kill the egg nucleus. The main reasons for this belief are that haploids obtained by other means develop no better than those obtained by u.v. An increase of u.v. treatment from 30 to 80 sec results in no increase in abnormalities sustained. The jelly is broken down and the vitelline membrane weakened. This enables the egg to be penetrated by a micropipette without causing damage or preventing healing. This investigation was undertaken to facilitate the analysis of nuclear transplantation experiments in Xenopus. The increased penetrability of eggs is of technical value for this purpose. The interpretation of these experiments is greatly facilitated by the knowledge that the egg cytoplasm need not be damaged by the u.v. and that the egg nucleus is completely inactivated so as not to interfere with the development of the egg.


Development ◽  
1963 ◽  
Vol 11 (1) ◽  
pp. 267-278
Author(s):  
Louie Hamilton

Haploid vertebrates may occur spontaneously but are very rare (Fankhauser, 1941; Humphrey & Fankhauser, 1957); however, haploids may be experimentally produced in fish (Swarup, 1959) and in mammals (Beatty, 1953), while amphibian eggs may be so treated that all developing embryos are haploid (Porter, 1939; Gurdon, 1960). The full descriptions of the development of haploid Rana pipiens (Porter, 1939) and R. nigromaculata (Miyada, 1960) apply so well to Xenopus laevis that only the most important points will be touched on here. Haploid amphibians may be identified at the beginning of gastrulation since their animal pole cells are smaller at a given stage than are those of diploids. In all haploid Anura the onset of gastrulation is delayed, and thereafter haploids become progressively more retarded in their development. Their neural plates are shorter, and when the neural folds have closed it can be seen that the embryos are microcephalic and suffer from lordosis and a bulging abdomen.


Development ◽  
1960 ◽  
Vol 8 (3) ◽  
pp. 327-340
Author(s):  
J. B. Gurdon

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.


Chromosoma ◽  
1967 ◽  
Vol 20 (4) ◽  
pp. 445-449 ◽  
Author(s):  
David R. Wolstenholme ◽  
Igor B. Dawid

1975 ◽  
Vol 45 (1) ◽  
pp. 44-55 ◽  
Author(s):  
Andrew C. Webb ◽  
Michael J. LaMarca ◽  
L.Dennis Smith

Nature ◽  
1958 ◽  
Vol 181 (4606) ◽  
pp. 424-424 ◽  
Author(s):  
M. FISCHBERG ◽  
J. B. GURDON ◽  
T. R. ELSDALE

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