Walther Flemming 1481776 219489864 2008-06-15T13:56:52Z Inwind 2901026 copyedit {{Infobox Scientist |name = Walther Flemming |box_width = |image =Walther_flemming.gif |image_width =150px |caption = Walther Flemming |birth_date = [[April 21]][[1843]] |birth_place = [[Sachsenberg]] |death_date = [[August 4]][[1905]] |death_place = [[Kiel]] |residence = |citizenship = |nationality = [[Germany]] |ethnicity = |field = |work_institutions = |alma_mater = [[University of Rostock]] |doctoral_advisor = |doctoral_students = |known_for = [[cytogenetics]] |author_abbrev_bot = |author_abbrev_zoo = |influences = |influenced = |prizes = |religion = |footnotes = |signature = }} '''Walther Flemming''' ([[April 21]][[1843]] - [[August 4]][[1905]]) was a [[Germany|German]] [[biologist]] and the founder of [[cytogenetics]]. [[image:Flemming1882Tafel1Fig14.jpg|thumb| Polytene chromosomes in a Chironimus salivary gland cell, one of over 100 drawings from Flemming's book ''Zellsubstanz, Kern und Zelltheilung'', 1882]] [[Image:Zell-substanz-book-illustrations.jpg|thumb|250px|right|Illustrations of cells with chromosomes and mitosis, from the book ''Zellsubstanz, Kern und Zelltheilung'', 1882]] 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]] [[dye]]s 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 [[fin]]s and [[gill]]s of [[salamander]]s. 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 [[Rudolf Virchow|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/], and one of the 10 most important discoveries in [[cell biology]] [http://science.discovery.com/convergence/100discoveries/big100/biology.html] (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 map]]s). 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. [[Category:1843 births|Flemming, Walther]] [[Category:1905 deaths|Flemming, Walther]] [[Category:German biologists|Flemming, Walther]] [[Category:Geneticists]] [[cs:Walther Flemming]] [[de:Walther Flemming]] [[es:Walther Flemming]] [[fr:Walther Flemming]] [[ja:ヴァルター・フレミング]] [[pt:Walther Flemming]] [[zh:華爾瑟·弗萊明]]