Hermann Henking
Hermann Paul August Otto Henking (born June 16, 1858 in Jerxheim near Braunschweig , † April 28, 1942 in Berlin ) was a German zoologist and developmental biologist.
life and work
The son of a pharmacist obtained his Abitur in Wolfenbüttel in 1878 . He then studied until 1882 in Göttingen , Leipzig and Freiburg / Br. Natural sciences with a major in zoology. He received his doctorate from the University of Göttingen in 1882.
During studies of the development of the sperm and egg cells of the fire bugs in 1891, Henking discovered what was later called the X chromosome . He found that 50 percent of the sperm contained a microscopically clearly visible structure more than the remaining 50 percent. Since he was not sure whether this was chromatin , he initially named the structure as the "X-factor". If an egg cell was fertilized with a sperm that contained this X-factor, a female developed from it; if the egg cell was fertilized with a sperm that did not have this “X-factor”, a male would develop. These were the first scientific indications of genotypic sex determination.
Almost at the same time as Henking, the American zoologist Clarence Erwin McClung discovered his so-called “accessory chromosome”, which could later also be identified with the X chromosome.
Building on the work of Henking and McClung, Nettie Stevens discovered in 1905 that the sex of insects is determined by different chromosomes and thus provided a decisive indication of the chromosome theory of inheritance. Despite these clear indications from Henking, McClung and Nettie Stevens, it would be almost 20 years before the chromosomal sex determination in mammals and thus also in humans could be clarified.
literature
- Horst-Rüdiger Jarck, Günter Scheel (Ed.): Braunschweigisches Biographisches Lexikon . 19th and 20th centuries , Hannover 1996, p. 261.
- Hans Querner: Henking, Hermann Paul August Otto. In: New German Biography (NDB). Volume 8, Duncker & Humblot, Berlin 1969, ISBN 3-428-00189-3 , p. 529 f. ( Digitized version ).
Individual evidence
- ↑ Hermann Henking: About spermatogenesis and its relationship to egg development in Pyrrhocoris apterus L. In: Journal for scientific zoology , Vol. 51 (1891).
Web links
- Literature by and about Hermann Henking in the catalog of the German National Library
| personal data | |
|---|---|
| SURNAME | Henking, Hermann |
| ALTERNATIVE NAMES | Henking, Hermann Paul August Otto (full name) |
| BRIEF DESCRIPTION | German zoologist and developmental biologist |
| DATE OF BIRTH | June 16, 1858 |
| PLACE OF BIRTH | Jerxheim |
| DATE OF DEATH | April 28, 1942 |
| Place of death | Berlin |