Beitr�ge zum Problem der Regulation und Induktion: Umkehrtransplantationen des mittleren Materialstreifens der beginnenden Gastrula von Triton alpestris

Töndury, Gian

doi:10.1007/bf00573465

Cited by 24 publications

(3 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several studies indicate that at earlier stages (during gastrulation), A-P properties of dorsal mesoderm are not yet fixed. Tondury [19] and Waddington and Yao [20] show that when one rotates large regions of the dorsal lip of young gastrula embryos, or when presumptive trunk and head organizer regions are interchanged, a proportion of embryos are completely normal. Deuchar [21] argues that even at late gastrula stages the inducing ability of regions of dorsal mesoderm is not yet fixed.…”

Section: Classical Embryological Experimentsmentioning

confidence: 99%

Neural induction and antero-posterior patterning in the amphibian embryo: past, present and future

Gould

Grainger

1997

CMLS, Cell. mol. life sci.

View full text Add to dashboard Cite

Neural induction and patterning in competent ectoderm occurs during gastrula and early neurula stages in response to signals from dorsal mesoderm. The earliest views of antero-posterior (A-P) patterning were modified beginning in the 1930s, as complexities concerning the timing of the pattern-forming process and potential sources of the patterning signals were revealed. In the 1950s and 1960s several different models for A-P patterning were proposed, all of which, however, bear a number of similarities, including a two-component system for generating A-P axial information in the embryo. Early attempts to identify neural-inducing molecules were largely unsuccessful due to technical limitations in biochemical analyses and concerns about assaying neural responses. The advent of modern molecular genetic technology has permitted more precise tests of a number of classic observations about the timing of A-P patterning and the sources of patterning signals. While some early observations have been confirmed, a number of new concepts have emerged in recent years, particularly concerning the source of patterning signals in the embryo. Striking progress has been made in identifying putative neural-inducing molecules, and recent experiments have begun to suggest how these might contribute to A-P patterning. While the successes in recent years have been revealing, many of the classic issues concerning neural induction and patterning remain essentially as they were when first defined many decades ago. The power of modern molecular genetics, however, should permit many of these issues to be significantly clarified in the decades to come.

show abstract

Section: Classical Embryological Experimentsmentioning

confidence: 99%

Neural induction and antero-posterior patterning in the amphibian embryo: past, present and future

Gould

Grainger

1997

CMLS, Cell. mol. life sci.

View full text Add to dashboard Cite

show abstract

“…Mangold (1923, 1925) first proved that, in amphibians, when the presumptive ectodermal cells were grafted into the mesodermal region, they can form mesodermal tissue and transform into endodermal tissue in the endodermal region. Lopashov (1935) and Tondury (1936) showed that mesodermal cells can transform into ectodermal cells. In induction experiments, Toivonen (1953, 1954), Yamada and Takata (1956), Yamada (1958), Chuang et al (1962) and Wang et al (1962) observed that presumptive ectodermal cells can produce mesodermal tissues, such as somites, notochord, primitive kidney tube and mesenchymal cells.…”

Section: Main Experimental Results and Comments On Tung’s Studies Of mentioning

confidence: 99%

“…Insufficient experimental results were obtained on the transformation of endodermal cells, except for those by Lopashov (1935) and Tondury (1936) on amphibians. However, in Amphioxus, Tung et al (1963) proved that not only presumptive ectodermal and mesodermal cells can transform into each other, but also both ectodermal and mesodermal cells can transform into endodermal cells.…”

Section: Main Experimental Results and Comments On Tung’s Studies Of mentioning

confidence: 99%

Contribution of late Professor T. C. Tung to the experimental embryology of Amphioxus

Yan

1999

Dev Growth Differ

View full text Add to dashboard Cite

Professor T. C. Tung ( Fig. 1) was a prominent experimental embryologist in China. He was born in Jin County, Zhejiang Province, China in 1902. After he obtained his Bachelor’s degree from the Department of Biology, Fudan University, Shanghai in 1927, he was appointed as a teaching assistant in that department until he moved to Belgium in 1930. He studied as a graduate student in Professors A. Brachet and A. M. Dalcq’s laboratory at the Universite Libre de Bruxelles, Belgium and obtained his Doctor of Science degree there in 1934. During that period, he made two short working visits to the Institute of Marine Biology in France and took one training course at Cambridge University (UK). In 1934, he was invited to return to China as a Full Professor to teach at several Chinese universities, (Shandong University in Qingdao, Shandong Province; the National University in Nanjing; and Fudan University in Shanghai). He spent 1 year at Yale University (USA) between 1948 and 1949 as an invited scientist in a joint research project and finally returned to China in 1949. He was Chairman of the Department of Zoology, Shandong University in Qingdao (1949~1952), Vice‐President of Shandong University (1952~1960), Director of the Marine Biological Institute, the Chinese Academy of Sciences (CAS) in Qingdao (1949~1958), Director of the Institute of Oceanology (CAS) in Qingdao (1959~1966), Director of the Institute of Zoology (CAS) in Beijing (1960–1962), member of CAS since 1955, Vice‐Chairman of the Biological and Geographical Division of CAS (1955~1958), Chairman of the Biological Division of CAS (1959~1979) and Vice‐President of CAS in Beijing (1978–1979). In spite of his administrative duties, he spent most of his life conducting bench work in his laboratories at the Institutes of Oceanology and Zoology, CAS, respectively, until he passed away in March 1979. Professor Tung’s main research interest was with classic experimental studies on the determination of the egg axis and symmetry planes of fertilized eggs, early differentiation and organizing substances of egg cytoplasm, induction between embryonic cells and cytoplasm in embryogenesis, immunological studies on nuclear transplanted eggs, and cell fusion etc., in several types of animals. He conducted his experiments on a number of invertebrates (ascidians and Amphioxus) and vertebrates (fish and amphibians) by means of very skilful microsurgical operations and the nuclear transplantation method. Among these topics, his studies on the organization and developmental potency of Amphioxus eggs were unique. His important contribution to this research field involved not only establishing a practical method for collecting and using this rare animal for experimental purposes, but also clarifying controversy about the nature and early development of its eggs. He also provided conclusive evidence to determine its evolutionary position between invertebrates and vertebrates.The present article briefly reviews the main results obtained by Professor Tung and his colleagues on Amphioxus. ...

show abstract

Bipartite axiation follows incomplete epiboly in zebrafish embryos treated with chemical teratogens

Baumann

Sander

1984

J. Exp. Zool.

View full text Add to dashboard Cite

Medial clefts in the axis of the trunk region are malformations known from many chordates and are mostly referred to as rachischisis anterior. In teleosts, rachischisis was previously ascribed either to secondary rifting of a single uniform axial rudiment, or to the establishment of two (half) axes and body halves physically separate from the very beginning. In order to decide between these conflicting interpretations, we treated zebrafish embryos during blastodisc stages and epiboly with several chemical teratogens causing rachischisis anterior. Treatment with ethanol, Colcemid, hydroxyurea, or cycloheximide was found to delay the proliferation and movements of the deep cells more strongly than the timing of cell differentiation, so that the deep cells embark on organogenesis before having reached their destinations in the uniform germ shield. Treatment with alpha-amanitin, on the other hand, seems primarily to affect the periblast and enveloping layer; the incomplete epiboly observed in these layers appears to restrain deep cell epiboly physically and thus to cause rachischisis. In both instances, the split condition of the embryo's trunk region is clearly due to the ectopic formation of physically separate body halves right from the beginning, a mode we call bipartite axiation. We also describe secondary anomalies specific for individual teratogens, and briefly discuss the possible origins of rachischisis anterior among other chordates including man.

show abstract

Beitr�ge zum Problem der Regulation und Induktion: Umkehrtransplantationen des mittleren Materialstreifens der beginnenden Gastrula von Triton alpestris

Cited by 24 publications

References 33 publications

Neural induction and antero-posterior patterning in the amphibian embryo: past, present and future

Neural induction and antero-posterior patterning in the amphibian embryo: past, present and future

Contribution of late Professor T. C. Tung to the experimental embryology of Amphioxus

Bipartite axiation follows incomplete epiboly in zebrafish embryos treated with chemical teratogens

Contact Info

Product

Resources

About