Embryology History - Viktor Hamburger - Revision history

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	{{#pmid:28353770}}		{{#pmid:28353770}}


			{{History People}}

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	~~{{History People}}~~

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Hamburger Hamilton Stages

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Hamburger Hamilton Stages

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	==The Heritage of Experimental Embryology: Hans Spemann and the Organizer==		==The Heritage of Experimental Embryology: Hans Spemann and the Organizer==

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	* University of Freiburg with [[Embryology_History_-_Hans_Spemann\|Hans Spemann]].		* University of Freiburg with [[Embryology_History_-_Hans_Spemann\|Hans Spemann]]. He was a graduate student in Spemann’s department at Freiburg during the years that the organizer graft experiments were being performed.

	* 1933 - United States, first in Chicago and then at Washington University.		* 1933 - United States, first in Chicago and then at Washington University.

	* 1988 - published "The Foundations of Experimental Embryology: Hans Spemann and the Organizer" (see review {{#pmid:17734868\|PMID17734868}})		* 1988 - published "[[#The Heritage of Experimental Embryology: Hans Spemann and the Organizer\|The Foundations of Experimental Embryology: Hans Spemann and the Organizer]]" (see also review {{#pmid:17734868\|PMID17734868}})
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			See also the review.{{#pmid:17734868\|PMID17734868}}

	===Reference===		===Reference===
	Search PubMed [https://www.ncbi.nlm.nih.gov/pubmed/?term=HAMBURGER%20V%5BAuthor%5D&cauthor=true&cauthor_uid=14824426 Hamburger V]		Search PubMed [https://www.ncbi.nlm.nih.gov/pubmed/?term=HAMBURGER%20V%5BAuthor%5D&cauthor=true&cauthor_uid=14824426 Hamburger V]
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	[[Category:Neural]]		[[Category:Neural]]
	[[Category:NGF]][[Category:Chicken]]		[[Category:NGF]][[Category:Chicken]]

Z8600021: /* The Heritage of Experimental Embryology: Hans Spemann and the Organizer */

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The Heritage of Experimental Embryology: Hans Spemann and the Organizer

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	:The organizer graft is a transplantation of tissue from the dorsal lip of the blastopore of an amphibian gastrula to the prospective ventral lip of another individual. When performed correctly, it yields a mirror syrnmetrical double dorsal embryo, rather like a pair of siamese twins joined belly to belly. The lower half of the duplication, often called the secondary axis, consists of a notochord derived from the graft and the remainder, mainly somites and neural tube, is induced from the ventral tissues of the host. The organizer graft was first reported in a famous paper by Spemann and Mangold in l924.		:The organizer graft is a transplantation of tissue from the dorsal lip of the blastopore of an amphibian gastrula to the prospective ventral lip of another individual. When performed correctly, it yields a mirror syrnmetrical double dorsal embryo, rather like a pair of siamese twins joined belly to belly. The lower half of the duplication, often called the secondary axis, consists of a notochord derived from the graft and the remainder, mainly somites and neural tube, is induced from the ventral tissues of the host. The organizer graft was first reported in a famous paper by Spemann and Mangold in l924.

	:Hamburger was a graduate student in ~~spemann’s~~ department at Freiburg during the years that the organizer grafts were first being performed. In his book he describes the scientific background, the character of experimental work at the time, and something of the personality of the individuals involved. It is certainly sobering to be reminded of the experimental difficulties of the time. In my laboratory today we generate two or three batches of Xenopus eggs each week, we manipulate their developmental rate with incubators at different temperatures, and we protect our grafts and explant cultures from infection with antibiotics. During the l920s, embryologists had to collect their eggs (usually newt eggs) from the wild during the brief breeding season in the spring. The whole year’s experiments would be performed in a mad rush, with horrific mortality rates due to poor culture conditions and to infection. It is because of these difficulties that the famous organizer paper describes only six cases, of which only two show good double-dorsal duplications.		:Hamburger was a graduate student in Spemann’s department at Freiburg during the years that the organizer grafts were first being performed. In his book he describes the scientific background, the character of experimental work at the time, and something of the personality of the individuals involved. It is certainly sobering to be reminded of the experimental difficulties of the time. In my laboratory today we generate two or three batches of Xenopus eggs each week, we manipulate their developmental rate with incubators at different temperatures, and we protect our grafts and explant cultures from infection with antibiotics. During the l920s, embryologists had to collect their eggs (usually newt eggs) from the wild during the brief breeding season in the spring. The whole year’s experiments would be performed in a mad rush, with horrific mortality rates due to poor culture conditions and to infection. It is because of these difficulties that the famous organizer paper describes only six cases, of which only two show good double-dorsal duplications.

	:Hamburger goes on to describe the subsequent work on early amphibian development. Unfortunately the organizer, which we now regard as the source of a dorsalizing positional Signal, was then seen mainly as an agent of neural induction. In 1932 three groups, all in Germany, simultaneously reported that killed organizer tissue had neural-inducing activity. This sparked off the famous «gold rush" for the chemical nature of the organizer, using neuralization of gastrula ectoderm as the assay. The hopelessness of such a task, with the biochemical techniques available over 50 years ago, may be assessed from the fact that we have only just succeeded in detecting a few picrograms per embryo of the mesoderm—inducing factor bFGF, using affinity ~~HPk~~ and ultrasensitive immunochemical methods. In fact, neural induction, particularly in newts, is a rather unspecific process and many substances can trigger it, including some synthetic chemicals which do not occur in embryos at all. This realization caused much consternation, and the high morale and sense of excitement evident in the literature of the ’20s and ’30s faded rapidly. The field as a whole went into eclipse during the second World War, partly because of the failure of the gold rush, but also because of the dispersal of the German scientists whose efforts had led the way throughout this period.		:Hamburger goes on to describe the subsequent work on early amphibian development. Unfortunately the organizer, which we now regard as the source of a dorsalizing positional Signal, was then seen mainly as an agent of neural induction. In 1932 three groups, all in Germany, simultaneously reported that killed organizer tissue had neural-inducing activity. This sparked off the famous «gold rush" for the chemical nature of the organizer, using neuralization of gastrula ectoderm as the assay. The hopelessness of such a task, with the biochemical techniques available over 50 years ago, may be assessed from the fact that we have only just succeeded in detecting a few picrograms per embryo of the mesoderm—inducing factor bFGF, using affinity HPLC and ultrasensitive immunochemical methods. In fact, neural induction, particularly in newts, is a rather unspecific process and many substances can trigger it, including some synthetic chemicals which do not occur in embryos at all. This realization caused much consternation, and the high morale and sense of excitement evident in the literature of the ’20s and ’30s faded rapidly. The field as a whole went into eclipse during the second World War, partly because of the failure of the gold rush, but also because of the dispersal of the German scientists whose efforts had led the way throughout this period.

	:The real legacy of the period was not so much the work on the organizer, which, with the benefit of hindsight can be seen as largely misdirected, but rather the formulation of a set of self-consistent concepts for the description and analysis of early development For example, fate, potency, induction, competence, and regulation were widely used as categories of explanation in this period. Now, when we have the technical means to investigate the inner workings of cells, this heritage is available not as a set of explanations but as a set of problems requiring solution.		:The real legacy of the period was not so much the work on the organizer, which, with the benefit of hindsight can be seen as largely misdirected, but rather the formulation of a set of self-consistent concepts for the description and analysis of early development For example, fate, potency, induction, competence, and regulation were widely used as categories of explanation in this period. Now, when we have the technical means to investigate the inner workings of cells, this heritage is available not as a set of explanations but as a set of problems requiring solution.

Z8600021: /* The Heritage of Experimental Embryology: Hans Spemann and the Organizer */

2018-08-24T01:07:27Z

The Heritage of Experimental Embryology: Hans Spemann and the Organizer

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	:"I came into embryology as a postdoctoral fellow in l974, when the subject was rather unfashionable and neglected. 0ver my first few years I spent long hours in the library and read with fascination of an earlier "golden age" between the two World Wars. slowly I pieced together the story of the organized It took time because most of the papers had to be retrieved from dusty stacks and because most were in German, a language I read poorly. How I would have loved to read Professor Hamburgers book then!		:"I came into embryology as a postdoctoral fellow in l974, when the subject was rather unfashionable and neglected. 0ver my first few years I spent long hours in the library and read with fascination of an earlier "golden age" between the two World Wars. slowly I pieced together the story of the organized It took time because most of the papers had to be retrieved from dusty stacks and because most were in German, a language I read poorly. How I would have loved to read Professor Hamburgers book then!

	:The organizer graft is a transplantation of tissue from the dorsal lip of the blastopore of an amphibian gastrula to the prospective ventral lip of another individual. When performed correctly, it yields a mirror syrnmetrical double dorsal embryo, rather like a pair of siamese twins joined belly to belly. The lower half of the duplication, often called the secondary axis, consists of a notochord derived from the graft and the remainder, mainly somites and neural tube, is induced from the ventral tissues of the host. The organizer graft was first reported in a famous paper by ~~spemann~~ and Mangold in l924.		:The organizer graft is a transplantation of tissue from the dorsal lip of the blastopore of an amphibian gastrula to the prospective ventral lip of another individual. When performed correctly, it yields a mirror syrnmetrical double dorsal embryo, rather like a pair of siamese twins joined belly to belly. The lower half of the duplication, often called the secondary axis, consists of a notochord derived from the graft and the remainder, mainly somites and neural tube, is induced from the ventral tissues of the host. The organizer graft was first reported in a famous paper by Spemann and Mangold in l924.

	:Hamburger was a graduate student in spemann’s department at Freiburg during the years that the organizer grafts were first being performed. In his book he describes the scientific background, the character of experimental work at the time, and something of the personality of the individuals involved. It is certainly sobering to be reminded of the experimental difficulties of the time. In my laboratory today we generate two or three batches of Xenopus eggs each week, we manipulate their developmental rate with incubators at different temperatures, and we protect our grafts and explant cultures from infection with antibiotics. During the l920s, embryologists had to collect their eggs (usually newt eggs) from the wild during the brief breeding season in the spring. The whole year’s experiments would be performed in a mad rush, with horrific mortality rates due to poor culture conditions and to infection. It is because of these difficulties that the famous organizer paper describes only six cases, of which only two show good double-dorsal duplications.		:Hamburger was a graduate student in spemann’s department at Freiburg during the years that the organizer grafts were first being performed. In his book he describes the scientific background, the character of experimental work at the time, and something of the personality of the individuals involved. It is certainly sobering to be reminded of the experimental difficulties of the time. In my laboratory today we generate two or three batches of Xenopus eggs each week, we manipulate their developmental rate with incubators at different temperatures, and we protect our grafts and explant cultures from infection with antibiotics. During the l920s, embryologists had to collect their eggs (usually newt eggs) from the wild during the brief breeding season in the spring. The whole year’s experiments would be performed in a mad rush, with horrific mortality rates due to poor culture conditions and to infection. It is because of these difficulties that the famous organizer paper describes only six cases, of which only two show good double-dorsal duplications.

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The Heritage of Experimental Embryology: Hans Spemann and the Organizer

@@ Line 45: / Line 45: @@
 Monographs on the History and Philosophy of Biology, New York and Oxford, Oxford University Press, l988, 8vo, pp. xii, 196, illus., L22.50.
-Below is an excerpt of a 1988 book review by Prof Jonathan Slack (ICRF Developmental Biology Unit, Oxford)
+A 1988 book review by Prof Jonathan Slack (ICRF Developmental Biology Unit, Oxford)
-I came into embryology as a postdoctoral fellow in l974, when the subject was rather
+:"I came into embryology as a postdoctoral fellow in l974, when the subject was rather unfashionable and neglected. 0ver my first few years I spent long hours in the library and read with fascination of an earlier "golden age" between the two World Wars. slowly I pieced together the story of the organized It took time because most of the papers had to be retrieved from dusty stacks and because most were in German, a language I read poorly. How I would have loved to read Professor Hamburgers book then!
-The organizer graft is a transplantation of tissue from the dorsal lip of the blastopore of an
+:The organizer graft is a transplantation of tissue from the dorsal lip of the blastopore of an amphibian gastrula to the prospective ventral lip of another individual. When performed correctly, it yields a mirror syrnmetrical double dorsal embryo, rather like a pair of siamese twins joined belly to belly. The lower half of the duplication, often called the secondary axis, consists of a notochord derived from the graft and the remainder, mainly somites and neural tube, is induced from the ventral tissues of the host. The organizer graft was first reported in a famous paper by spemann and Mangold in l924.
-Hamburger was a graduate student in spemann’s department at Freiburg during the years
+:Hamburger was a graduate student in spemann’s department at Freiburg during the years that the organizer grafts were first being performed. In his book he describes the scientific background, the character of experimental work at the time, and something of the personality of the individuals involved. It is certainly sobering to be reminded of the experimental difficulties of the time. In my laboratory today we generate two or three batches of Xenopus eggs each week, we manipulate their developmental rate with incubators at different temperatures, and we protect our grafts and explant cultures from infection with antibiotics. During the l920s, embryologists had to collect their eggs (usually newt eggs) from the wild during the brief breeding season in the spring. The whole year’s experiments would be performed in a mad rush, with horrific mortality rates due to poor culture conditions and to infection. It is because of these difficulties that the famous organizer paper describes only six cases, of which only two show good double-dorsal duplications.
-Hamburger goes on to describe the subsequent work on early amphibian development.
+:Hamburger goes on to describe the subsequent work on early amphibian development. Unfortunately the organizer, which we now regard as the source of a dorsalizing positional Signal, was then seen mainly as an agent of neural induction. In 1932 three groups, all in Germany, simultaneously reported that killed organizer tissue had neural-inducing activity. This sparked off the famous «gold rush" for the chemical nature of the organizer, using neuralization of gastrula ectoderm as the assay. The hopelessness of such a task, with the biochemical techniques available over 50 years ago, may be assessed from the fact that we have only just succeeded in detecting a few picrograms per embryo of the mesoderm—inducing factor bFGF, using affinity HPk and ultrasensitive immunochemical methods. In fact, neural induction, particularly in newts, is a rather unspecific process and many substances can trigger it, including some synthetic chemicals which do not occur in embryos at all. This realization caused much consternation, and the high morale and sense of excitement evident in the literature of the ’20s and ’30s faded rapidly. The field as a whole went into eclipse during the second World War, partly because of the failure of the gold rush, but also because of the dispersal of the German scientists whose efforts had led the way throughout this period.
-The real legacy of the period was not so much the work on the organizer, which, with the
+:The real legacy of the period was not so much the work on the organizer, which, with the benefit of hindsight can be seen as largely misdirected, but rather the formulation of a set of self-consistent concepts for the description and analysis of early development For example, fate, potency, induction, competence, and regulation were widely used as categories of explanation in this period. Now, when we have the technical means to investigate the inner workings of cells, this heritage is available not as a set of explanations but as a set of problems requiring solution.
+:Probably no one did more in this vital task than Johannes Holtfreter, who receives extensive coverage in the second half of the book. His in vitm isolation experiments and his work on the regional specificity of neural induction particularly helped to define the style and standard of experimental embryology for decades to come.
-potency, induction, competence, and regulation were widely used as categories of explanation in
+:Hamburger’s book really finishes at the second World War, although one or two later experiments are described. The modern era, starting with Nieuwkoop’s discovery of mesoderm induction, is not covered. so this is not really a book for those who want to understand amphibian development, but rather a lucid and interesting account of a critical period in scientific history. It has a special fascination because it is written by a participant who can not only tell us what happened, but also what it felt like at the time."

Z8600021: /* Hamburger Hamilton Stages */

2018-08-24T01:04:28Z

Hamburger Hamilton Stages

← Older revision	Revision as of 12:04, 24 August 2018
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		==The Heritage of Experimental Embryology: Hans Spemann and the Organizer==
		Monographs on the History and Philosophy of Biology, New York and Oxford, Oxford University Press, l988, 8vo, pp. xii, 196, illus., L22.50.

		Below is an excerpt of a 1988 book review by Prof Jonathan Slack (ICRF Developmental Biology Unit, Oxford)

		I came into embryology as a postdoctoral fellow in l974, when the subject was rather
		unfashionable and neglected. 0ver my first few years I spent long hours in the library and read
		with fascination of an earlier «golden age" between the two World Wars. slowly I pieced
		together the story of the organized It toolc time because most of the papers had to be retrieved
		from dusty stacks and because most were in German, a language I read poorly. How I would
		have loved to read Professor Hamburgers book then!

		The organizer graft is a transplantation of tissue from the dorsal lip of the blastopore of an
		amphibian gastrula to the prospective ventral lip of another individual. When performed
		correctly, it yields a mirror syrnmetrical double dorsal embryo, rather like a pair of siamese twins
		joined belly to belly. The lower half of the duplication, often called the secondary axis, consists of
		a notochord derived from the graft and the remainder, mainly somites and neural tube, is
		induced from the ventral tissues of the host. The organizer graft was first reported in a famous
		paper by spemann and Mangold in l924.

		Hamburger was a graduate student in spemann’s department at Freiburg during the years
		that the organizer grafts were first being performed. In his book he describes the scientific
		background, the character of experimental work at the time, and something of the personality of
		the individuals involved. It is certainly sobering to be reminded of the experimental difficulties of
		the time. In my laboratory today we generate two or three batches of Xenopus eggs each week, we
		manipulate their developmental rate with incubators at different temperatures, and we protect
		our grafts and explant cultures from infection with antibiotics. During the l920s, embryologists
		had to collect their eggs (usually newt eggs) from the wild during the brief breeding season in the
		spring. The whole year’s experiments would be performed in a mad rush, with horrific mortality
		rates due to poor culture conditions and to infection. It is because of these difficulties that the
		famous organizer paper describes only six cases, of which only two show good double-dorsal
		duplications.

		Hamburger goes on to describe the subsequent work on early amphibian development.
		Unfortunately the organizer, which we now regard as the source of a dorsalizing positional
		Signal, was then seen mainly as an agent of neural induction. In 1932 three groups, all in
		Germany, simultaneously reported that killed organizer tissue had neural-inducing activity. This
		sparked off the famous «gold rush" for the chemical nature of the organizer, using neuralization
		of gastrula ectoderm as the assay. The hopelessness of such a task, with the biochemical
		techniques available over 50 years ago, may be assessed from the fact that we have only just
		succeeded in detecting a few picrograms per embryo of the mesoderm—inducing factor bFGF,
		using affinity HPk and ultrasensitive immunochemical methods. In fact, neural induction,
		particularly in newts, is a rather unspecific process and many substances can trigger it, including
		some synthetic chemicals which do not occur in embryos at all. This realization caused much
		consternation, and the high morale and sense of excitement evident in the literature of the ’20s
		and ’30s faded rapidly. The field as a whole went into eclipse during the second World War,
		partly because of the failure of the gold rush, but also because of the dispersal of the German
		scientists whose efforts had led the way throughout this period.

		The real legacy of the period was not so much the work on the organizer, which, with the
		benefit of hindsight can be seen as largely misdirected, but rather the formulation of a set of
		self-consistent concepts for the description and analysis of early development For example, fate,

		392
		Zool( Reviews

		potency, induction, competence, and regulation were widely used as categories of explanation in
		this period. Now, when we have the technical means to investigate the inner workings of cells,
		this heritage is available not as a set of explanations but as a set of problems requiring solution.

		Probably no one did more in this vital taslsc than Johannes Holtfreter, who receives extensive
		coverage in the second half of the book. His in vitm isolation experiments and his work on the
		regional specificity of neural induction particularly helped to define the style and standard of
		experimental embryology for decades to come.

		Hamburger’s book really finishes at the second World War, although one or two later
		experiments are described. The modern era, starting with Nieuwkoop’s discovery of mesoderm
		induction, is not covered. so this is not really a book for those who want to understand
		amphibian development, but rather a lucid and interesting account of a critical period in
		scientific history. It has a special fascination because it is written by a participant who can not
		only tell us what happened, but also what it felt like at the time.

Z8600021 at 00:58, 24 August 2018

2018-08-24T00:58:46Z

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	:'''Links:''' {{Neural}} \| [[Hamburger Hamilton Stages]] \| {{NGF}} ~~\| [http://books.google.com.au/books/about/The_heritage_of_experimental_embryology.html? The heritage of experimental embryology]~~		:'''Links:''' {{Neural}} \| [[Hamburger Hamilton Stages]] \| {{NGF}}

	<br>		<br>

Z8600021: /* Introduction */

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Introduction

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	Hans Spemann (1869 - 1941)		Hans Spemann (1869 - 1941)
	\| valign=top\|		\| valign=top\|



	* University of Freiburg with [[Embryology_History_-_Hans_Spemann\|Hans Spemann]].		* University of Freiburg with [[Embryology_History_-_Hans_Spemann\|Hans Spemann]].