Difference between revisions of "Embryology History - Thomas Morgan"

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==Experimental Embryology in the United States==
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[[Book - The Emergence of Experimental Embryology in the United States#T.H. Morgan|Excerpt]] - The following is an excerpt from [[Book - The Emergence of Experimental Embryology in the United States|The Emergence of Experimental Embryology in the United States]] (1990) by S. Robert Hilfer, Ph.D.
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:[[Embryology History - Thomas Morgan|T.H. Morgan]] was the most influential scientist in establishing genetics as a separate field of biology. In doing so, he changed from a strong supporter of totally regulative development to a proponent of nuclear control of development. He also gave up at least temporarily his interests in embryology to pursue the establishment of the genetic basis of inheritance. He was instrumental in causing a split between embryology and genetics that lasted for many years. In fact, O.E. Schotte pictured the way an embryologist and geneticist looked upon the cell during this time as either mostly cytoplasm or mostly nucleus (Fig. 12).
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:Morgan was concerned primarily with establishing the gene as the basis of genetics. He did this by examining mutants and established Drosophila as the organism of choice for these studies. He was responsible for describing many characteristics and showing that they could be related to sequential arrays on specific chromosomes. Nevertheless, Morgan retained a concern for with the problem of how genetic control might be exercised during development. In his Nobel Prize address, delivered in 1934, Morgan (1935, p. 15) remarked that "It is conceivable that different batteries of genes come into action one after the other, as the embryo passes through its stages of development. This sequence might be assumed to be an automatic property of the chain of genes." In discussing the genetic control of development, he stated (Morgan, 1935, p. 16): We have also come to realize that the problem of development is not as simple as I have so far assumed to be the case, for it depends, not only on independent cell differentiation of individual cells, but also on interactions between cells, both in the early stages of development and on the action of hormones on the adult organ systems. At the end of the last century, when experimental embryology greatly flourished, some of the most thoughtful students of embryology laid emphasis on the importance of the interaction of the parts on each other, in contrast to the theories of Roux and Weismann that attempted to explain development as a progressive series of events that are the outcome of selfdifferentiating processes or, as we would say today, by the sorting out of genes during the cleavage of the egg. At that time there was almost no experimental evidence as to the nature of the postulated interaction of the cells. The idea was a generalization rather than an experimentally determined conclusion, and, unfortunately, took a metaphysical turn.
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:Today this has changed, and owing mainly to the extensive experiments of the [[Embryology_History_-_Hans_Spemann|Spemann]]. school of Germany, and to the brilliant results of Horstadius of Stockholm, we have positive evidence of the farreaching importance of interactions between cells of different regions of the developing egg. This implies that original differences are already present, either in the undivided egg or in the early formed cells of different regions. From the point of view under consideration results of this kind are of interest because they bring up once more, in a slightly different form, the problem as to whether the organizer acts first on the protoplasm of the neighboring region with which it comes in contact, and through the protoplasm of the cells on the genes; or whether the influence is more directly on the genes. In either case the problem under discussion remains exactly where it was before. The conception of an organizer has not as yet helped to solve the more fundamental relation between genes and differentiation, although it certainly marks an important step forward in our understanding of embryonic development. Answers to the questions raised above are becoming available only today with the advent of molecular genetics and a renewed merging of interest in developmental biology and genetics.
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==References==
 
==References==
 
===Books===
 
===Books===
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===Articles===
 
===Articles===
 
<pubmed>21010858</pubmed>
 
<pubmed>21010858</pubmed>
 +
<pubmed>17840456</pubmed>
 
<pubmed>17754102</pubmed>
 
<pubmed>17754102</pubmed>
<pubmed>17840456</pubmed>
 
 
<pubmed>17788502</pubmed>
 
<pubmed>17788502</pubmed>
 
<pubmed>16576691</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1085317 PMC1085317]
 
<pubmed>16576691</pubmed>| [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1085317 PMC1085317]

Latest revision as of 01:03, 3 June 2017

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Introduction

Thomas Hunt Morgan (1866 – 1945)
Thomas Hunt Morgan (1866 – 1945)
Thomas Hunt Morgan (1866 – 1945)
Thomas Hunt Morgan (1920)
The male and female vinegar fly, Drosophila melanogaster
The male and female vinegar fly (Drosophila melanogaster)

Thomas Hunt Morgan (1866–1945) was an American geneticist and embryologist who studied the development and genetics of the vinegar fly (Drosophila melanogaster). He began reapplying Mendel's early plant studies to this animal model system and was warded the 1933 Nobel Prize in Medicine for his work.


  • 1908 - looking for an inexpensive animal that could be breed quickly and in limited space and Castle suggested the drosophila. Through Morgan’s studies of heredity he discovered the white-eyed mutation in the drosophila.
  • 1910 - at Columbia University T.H Morgan and his students work on the top floor of the Schermerhorn Hall and it became known as the fly room. Students of the Fly Room were A.H. Sturtevant, C.B Bridges and H.J. Muller.


Links: Fly Development | 1925 - Evolution and genetics |Molecular Development
Embryologists: William Hunter | Wilhelm Roux | Caspar Wolff | Wilhelm His | Oscar Hertwig | Julius Kollmann | Hans Spemann | Francis Balfour | Charles Minot | Ambrosius Hubrecht | Charles Bardeen | Franz Keibel | Franklin Mall | Florence Sabin | George Streeter | George Corner | James Hill | Jan Florian | Thomas Bryce | Thomas Morgan | Ernest Frazer | Francisco Orts-Llorca | José Doménech Mateu | Frederic Lewis | Arthur Meyer | Robert Meyer | Erich Blechschmidt | Klaus Hinrichsen | Hideo Nishimura | Arthur Hertig | John Rock | Viktor Hamburger | Mary Lyon | Nicole Le Douarin | Robert Winston | Fabiola Müller | Ronan O'Rahilly | Robert Edwards | John Gurdon | Shinya Yamanaka | Embryology History | Category:People
Related Histology Researchers  
Santiago Ramón y Cajal | Camillo Golgi


Experimental Embryology in the United States

Excerpt - The following is an excerpt from The Emergence of Experimental Embryology in the United States (1990) by S. Robert Hilfer, Ph.D.

T.H. Morgan was the most influential scientist in establishing genetics as a separate field of biology. In doing so, he changed from a strong supporter of totally regulative development to a proponent of nuclear control of development. He also gave up at least temporarily his interests in embryology to pursue the establishment of the genetic basis of inheritance. He was instrumental in causing a split between embryology and genetics that lasted for many years. In fact, O.E. Schotte pictured the way an embryologist and geneticist looked upon the cell during this time as either mostly cytoplasm or mostly nucleus (Fig. 12).


Morgan was concerned primarily with establishing the gene as the basis of genetics. He did this by examining mutants and established Drosophila as the organism of choice for these studies. He was responsible for describing many characteristics and showing that they could be related to sequential arrays on specific chromosomes. Nevertheless, Morgan retained a concern for with the problem of how genetic control might be exercised during development. In his Nobel Prize address, delivered in 1934, Morgan (1935, p. 15) remarked that "It is conceivable that different batteries of genes come into action one after the other, as the embryo passes through its stages of development. This sequence might be assumed to be an automatic property of the chain of genes." In discussing the genetic control of development, he stated (Morgan, 1935, p. 16): We have also come to realize that the problem of development is not as simple as I have so far assumed to be the case, for it depends, not only on independent cell differentiation of individual cells, but also on interactions between cells, both in the early stages of development and on the action of hormones on the adult organ systems. At the end of the last century, when experimental embryology greatly flourished, some of the most thoughtful students of embryology laid emphasis on the importance of the interaction of the parts on each other, in contrast to the theories of Roux and Weismann that attempted to explain development as a progressive series of events that are the outcome of selfdifferentiating processes or, as we would say today, by the sorting out of genes during the cleavage of the egg. At that time there was almost no experimental evidence as to the nature of the postulated interaction of the cells. The idea was a generalization rather than an experimentally determined conclusion, and, unfortunately, took a metaphysical turn.


Today this has changed, and owing mainly to the extensive experiments of the Spemann. school of Germany, and to the brilliant results of Horstadius of Stockholm, we have positive evidence of the farreaching importance of interactions between cells of different regions of the developing egg. This implies that original differences are already present, either in the undivided egg or in the early formed cells of different regions. From the point of view under consideration results of this kind are of interest because they bring up once more, in a slightly different form, the problem as to whether the organizer acts first on the protoplasm of the neighboring region with which it comes in contact, and through the protoplasm of the cells on the genes; or whether the influence is more directly on the genes. In either case the problem under discussion remains exactly where it was before. The conception of an organizer has not as yet helped to solve the more fundamental relation between genes and differentiation, although it certainly marks an important step forward in our understanding of embryonic development. Answers to the questions raised above are becoming available only today with the advent of molecular genetics and a renewed merging of interest in developmental biology and genetics.



References

Books

Morgan1925.jpg Morgan, T. H. (1925). Evolution and genetics. Princeton: Princeton University Press.

Articles

<pubmed>21010858</pubmed> <pubmed>17840456</pubmed> <pubmed>17754102</pubmed> <pubmed>17788502</pubmed> <pubmed>16576691</pubmed>| PMC1085317 <pubmed>16576482</pubmed>| PMC1084455 <pubmed>19871778</pubmed>| PMC2140342 <pubmed>16576369</pubmed>| PMC1091562 <pubmed>19871722</pubmed> <pubmed>16576035</pubmed>| PMC1090846 <pubmed>17817201</pubmed> <pubmed>17741940</pubmed> <pubmed>17817675</pubmed>

Search PubMed: Morgan TH

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Cite this page: Hill, M.A. (2019, September 20) Embryology Embryology History - Thomas Morgan. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Embryology_History_-_Thomas_Morgan

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