Johannes Holtfreter

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Johannes Friedrich Karl Holtfreter (born January 9, 1901 in Richtenberg , † November 13, 1992 in Rochester (New York) ) was a German-American embryologist .

Holtfreter grew up in Richtenberg and Stralsund and from 1917 studied natural sciences at the University of Rostock and at the University of Leipzig and received his doctorate in 1924 at the Albert-Ludwigs-University of Freiburg under Hans Spemann with a thesis on the development of the liver and pancreas in the frog embryo . Afterwards he was supposed to do research at the Zoological Station in Naples, but used this time mainly to travel to Italy and Europe and deal with painting. In 1928 he became Otto Mangold's assistant at the Kaiser Wilhelm Institute in Berlin and did research in the field of embryology again.

In Berlin, Holtfreter developed a saline solution named after him in which frog embryos survived better. He also developed sterile techniques to avoid bacterial contamination. In doing so, he continued the experiments on the Spemann organizer that he had started with Spemann in Freiburg and was able to show that he retained the ability to induce even after he was killed. In doing so, he proved that the chemicals produced by the organizer were responsible for their role in determining the body plan. He discovered that there were several of these chemicals, one for inducing nerve tissue and the other for mesodermal tissue.

In 1934 Holtfreter went to the Ludwig Maximilians University in Munich , studied embryos in the gastrula stage and introduced the first fate maps. From Berlin he already had contacts with Joseph Needham and Conrad Hal Waddington . Needham made it possible for him to flee to England in 1939 after he came into conflict with the Gestapo . There he was interned as an enemy alien and transferred to Canada , where he was released in 1942. He then went to McGill University in Montreal, Canada on a Rockefeller Fellowship . There he dealt mainly with gastrulation by observing cell movements. In 1946 he became an assistant professor at the University of Rochester in the USA, where he received a full professorship in 1948. In 1949 he was offered a position at the Kaiser Wilhelm Institute for Biology , but did not return to Germany.

In a 1955 essay with Viktor Hamburger on amphibian developmental biology, Holtfreter rejected the concept of a gradient of signaling molecules that controls embryonic development, preferring instead direct cell-cell interaction.

Holtfreter was married, his marriage remained childless. He was a member of the Leopoldina , the Royal Swedish Academy of Sciences , the American Academy of Arts and Sciences (1957) and the National Academy of Sciences (1955). He received an honorary doctorate from the University of Freiburg (1975).

literature

  • Joseph T. Bagnara: In Memoriam Johannes FC Holtfreter (1901-1992). In: Developmental Biology. 158, pp. 1-8 (1993).
  • John Gerhart: Johannes Holtfreter's Contributions to Ongoing Studies of the Organizer. In: Developmental Dynamics . 205: 245-256 (1996).
  • John Gerhart: Johannes Holtfreter: January 9, 1901 – November 13, 1992. In: Biographical Memoirs National Academy of Sciences (US) . Volume 73 (1998), pp. 209-228. ( PDF )
  • Lothar fights : Holtfreter, Johannes (1901–1992) . In: Dirk Alvermann , Nils Jörn (Hrsg.): Biographisches Lexikon für Pommern . Volume 2 (= publications of the Historical Commission for Pomerania. Series V, Volume 48.2). Böhlau Verlag, Cologne Weimar Vienna 2015, ISBN 978-3-412-22541-4 , pp. 127–130.
  • Ray Keller: Holtfreter Revisited. Unsolved Problems in Amphibian Morphogenesis. In: Developmental Dynamics . 205: 257-264 (1996).
  • Reminiscences on the life and work of Johannes Holtfreter . In: SF Gilbert: A Conceptual History of Modern Embryology. Johns Hopkins University Press, Baltimore 1991, pp. 109-127.

Web links

Individual evidence

  1. ^ J. Holtfreter, V. Hamburger: Amphibians. In: BH Willier, PA Weiss, V. Hamburger (Ed.): Analysis of Development. WB Saunders, 1955, pp. 230-296.
personal data
SURNAME Holtfreter, Johannes
ALTERNATIVE NAMES Holtfreter, Johannes Friedrich Karl (full name)
BRIEF DESCRIPTION German-American embryologist
DATE OF BIRTH January 9, 1901
PLACE OF BIRTH Richtenberg
DATE OF DEATH November 13, 1992
Place of death Rochester (New York)