Walther Flemming

Infobox Scientist
name = Walther Flemming
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caption = Walther Flemming
birth_date = April 211843
birth_place = Sachsenberg
death_date = August 41905
death_place = Kiel
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nationality = Germany
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alma_mater = University of Rostock
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known_for = cytogenetics
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Walther Flemming (April 211843 - August 41905) was a German biologist and the founder of cytogenetics.

He was born in Sachsenberg near Schwerin as the fifth child and only son of the psychiatrist Carl Friedrich Flemming (1799-1880) and his second wife, Auguste Winter. He did his basic studies at the "Gymnasium der Residenzstadt", where one of his colleagues and lifelong friends was writer Heinrich Seidel. [http://www.zellbiologie.de/journal/artikel/26_2_2004.pdf] Flemming trained in medicine at the University of Rostock, graduating in 1868. Afterwards. he served in 1870-1871 as a military physician in the Franco-Prussian War. From 1873 to 1876 he worked as a teacher at the University of Prague. In 1876 he accepted a post as a professor of anatomy at the University of Kiel. He became the director of the Anatomical Institute and stayed there until his death.

Making use of aniline dyes he was able to find a structure which strongly absorbed basophilic dyes, which he named chromatin. He identified that chromatin was correlated to threadlike structures in the cell nucleus— the chromosomes (meaning "coloured body"), which were thus named later on by German anatomist Wilhelm von Waldeyer-Hartz (1836-1921). The Belgian scientist Edouard Van Beneden (1846-1910) had independently observed them, too.

Flemming investigated the process of cell division and the distribution of chromosomes to the daughter nuclei, a process he called mitosis from the Greek word for thread. However, he did not yet realize the splitting into identical halves, the daughter chromatids. He studied mitosis both "in vivo" and in stained preparations, using as the source of biological material the fins and gills of salamanders. These results were published in 1882 in the seminal book "Zellsubstanz, Kern und Zelltheilung" (1882; Cell Substance, Nucleus and Cell Division). On the basis of his discoveries, Flemming surmised for the first time that all cell nuclei came from another predecessor nucleus (he coined the phrase "omnis nucleus e nucleo", after Virchow's "omnis cellula e cellula").

Flemming was unaware of Gregor Mendel's (1822-1884) work on heredity, so he did not make the connection between his observations and genetic inheritance. Two decades would pass before the significance of Flemming's work was truly realized with the rediscovery of Mendel's rules. His discovery of mitosis and chromosomes is considered one of the 100 most important scientific discoveries of all times, [ [http://carnegieinstitution.org/cover/top_100/ 100 Greatest Discoveries - Carnegie Institution ] at carnegieinstitution.org] and one of the 10 most important discoveries in cell biology [ [http://science.discovery.com/convergence/100discoveries/big100/biology.html The Science Channel :: 100 Greatest Discoveries: Biology ] at science.discovery.com] (together with August Weismann's (1834-1914) discovery of meiosis, Theodor Schwann (1810-1882) and Matthias Schleiden's (1804-1881) cell theory and Thomas Hunt Morgan's (1866-1945) first genetic maps).

Flemming's name is honoured by a medal awarded by the German Society for Cell Biology (Deutschen Gesellschaft für Zellbiologie).

References

*Citation
id = PMID:7015236
url= http://www.ncbi.nlm.nih.gov/pubmed/7015236
last=Lukács
first=D
publication-date=1981 Feb 8
year=1981
title= [Walter Flemming, discoverer of chromatin and mitotic cell division]
volume=122
issue=6
periodical=Orvosi hetilap
pages=349-50
*Citation
id = PMID:10829597
url= http://www.ncbi.nlm.nih.gov/pubmed/10829597
last=Latronico
first=N
publication-date=
year=
title= [Heredity, constitution and diathesis]
volume=52
issue=1-2
periodical=Minerva Pediatr.
pages=81-115
*Citation
id = PMID:7050007
url= http://www.ncbi.nlm.nih.gov/pubmed/7050007
last=Breathnach
first=C S
publication-date=1982 Jun
year=1982
title=Biographical sketches No. 18--Flemming.
volume=75
issue=6
periodical=Irish medical journal
pages=177
*Citation
id = PMID:11413469
url= http://www.ncbi.nlm.nih.gov/pubmed/11413469
last=Paweletz
first=N
publication-date=2001 Jan
year=2001
title=Walther Flemming: pioneer of mitosis research.
volume=2
issue=1
periodical=Nat. Rev. Mol. Cell Biol.
pages=72-5
doi = 10.1038/35048077
* Flemming, W. Beitrage zur Kenntniss der Zelle und ihrer Lebenserscheinungen. "Arch. Mikroskop. Anat." 16:302-436 (1878) and 18:151-289 (1880). Reprinted in: "J. Cell Biol." 25:581-589 (1965).
* Carlson, E.A. The Analysis of Mitosis Shifts Attention to the Chromosomes. In: "Mendel's Legacy. The Origins of Classical Genetics". p. 24-5, CSHL Press, 2004. ISBN 0-87969-675-3.

External links

* [http://www.laskerfoundation.org/news/gnn/timeline/1882a.html Walther Flemming Biography] . Lasker Labs
* [http://www.dietzellab.de/goodies/history/ Zellsubstanz, Kern und Zelltheilung] . Original text of the book, as PDF (In German).
* [http://www.zellbiologie.de/journal/artikel/3_2_2003.pdf Walter Flemming Medaille] . In PDF, in German.