Freemartinism
As Freemartin or Freemartin syndrome (from the English unknown word derivation, in English as a free-Martin proved in the 17th century.) An innate will malformation called that occurs in females, which consists of a Mehrlingsträchtigkeit with at least one male fetus come . The reason for the appearance of the malformation is a form of chimerism . Freemartinism is most common in domestic cattle (93% of all same-sex multiple pregnancies), but can also occur in other species .
Mechanism of origin
During pregnancy , anastomoses of the fetal blood vessels form in the placenta , through which an exchange of blood between the fetuses takes place. Since the fetuses are in the immune tolerance stage before birth , the blood cells of the other fetuses are not recognized as foreign, so that there is a lifelong mutual immune tolerance of these individuals. Through this exchange of blood cells, all fetuses in a multiple pregnancy become chimeras .
The development of the male sexual organs in the embryo and fetus is controlled by hormones ( testosterone and anti-Müllerian hormone ); in the absence of these, the embryo develops the female phenotype . However, through the exchange of blood, these hormones also become effective in genetically female fetuses, so that the female reproductive organs are underdeveloped.
Clinical picture
Genetically female cattle affected by freemartinism are known as pinch . Cytogenetically , they are XX / XY chimeras . With them, the female genitalia is more or less masculinized : Depending on the severity, hypoplasia of the ovary occurs , or instead of the ovaries, ovotests or even testicular-like structures are formed. Fallopian tubes , uterus, and vagina are hypoplastic or even absent. The clitoris is enlarged and in severe cases transformed into a penis-like organ, which can go as far as hypoplastic testicles in a scrotum and a generally male habitus .
With rare exceptions, pinches are sterile. Since minor cases cannot easily be recognized as being affected by freemartinism, a breeder can incur financial damage from raising such animals with a view to possible use as a breeding and dairy cow.
reception
In the dystopian novel Brave New World by Aldous Huxley , there is a large percentage of the female population of so-called "Free Martins", d. H. sterile bred women. Huxley's choice of this name is interpreted by some commentators to mean that these parts of the population are socially regarded as cattle.
literature
- A. Herzog: Pareys Lexicon of Syndromes - Hereditary and breeding diseases of domestic and farm animals. Parey Buchverlag, Berlin 2001, ISBN 3-8263-3237-7 , pp. 155-159
Individual evidence
- ↑ Oxford English Dictionary online, DRAFT REVISION June 2008, www.oed.com .
- ↑ Jesús Isaías Gómez López: Reinterpreting "Un mundo feliz" . In: Aldous Huxley Annual, Vol. 12/13, 2012/2013, ISBN 978-3-643-90587-1 , pp. 286f.
