Genetically modified mice of unconventional orientation
Transgenic "lesbian mice" have been createdAlexey Tymoshenko, GZT.RU
Biologists have received a new line of transgenic mice.
These animals are notable not only for the absence of one protein, but also for the homosexual orientation of the females.
It is certainly impossible to say that the appearance of mice that prefer other females instead of males explains the phenomenon of homosexuality in women. But, as researchers from Korea write on the pages of the journal BMC Genetics, transgenic animals will at least prove to be a useful object for further study of the biological foundations of sexual orientation.
About how homosexuality manifests itself in people, most readers probably have a general idea. But how can a mouse that prefers females behave, that is, a "lesbian mouse" (in order to avoid incorrect comparisons, let's take the phrase in quotation marks - people's sexual orientation has a clearly more complex nature)? Males who have anal intercourse with other males are not uncommon in mice, but what about females who, by definition, are not capable of penetrating the vagina of other females?
The researchers noted two signs of non-traditional orientation in the experimental rodents. The first and most obvious was that the mutant females periodically tried to jump on their cage neighbors in the same way that males do to perform sexual intercourse. The second sign was not so obvious – the "lesbians" sniffed the urine traces of females for longer, and not males – while ordinary mice demonstrate the exact opposite behavior.
The marks left by urine play the role of a kind of marriage announcements for rodents. A female ready for mating (whose hormonal cycle allows fertilization) leaves traces that serve as a direct analogue of the text "looking for a partner for living together" for males. Similarly, the marks of males can also be compared with "an attractive man in the prime of life is looking for a gentle and responsive life partner."
It is interesting to note that the mutation did not affect the ability to conceive, bear and raise offspring. The only thing is that not every male could get close to a transgenic female – most of the suitors of experimental animals preferred to be driven away immediately.
What was changed?
What made the mice change their behavior so much? Genetic engineering specialists deprived them of a single gene encoding the enzyme fucose mutoratase, or FucM for short. What is hidden behind this name?
Like the vast majority of all enzymes (compounds that provide a particular biochemical reaction), the name FucM for specialists speaks for itself. Fucose is a type of monosaccharides (the most famous examples are glucose, fructose and lactose, "milk sugar"), and mutarotation is the process of rearranging a molecule from one configuration to another. The ending "-aza" indicates that we are talking about an enzyme: according to one of the jokes of biochemists, it would be more correct to call a hammer "gvozdestenkozabivase" (which, how and where, is aza).
The transformation of fucose from one form to another allows it to integrate into some proteins. And this process, as it was shown back in the late 1990s, plays an important role in the formation of a number of rare but very serious hereditary diseases in humans. Visual disturbances, coordination of movements, feelings of satiety – mice that lacked the FucM gene were not created at all to study the phenomenon of female homosexuality!
However, as the anatomical study that followed the behavioral tests showed, the absence of this gene affected the development of nerve cells in the so-called preoptic region of the anterior lobe of the hypothalamus. This relatively small area is responsible for both the thermoregulation of the body and affects the production of female sex hormones – and from here it is already close to sexual behavior.
Portal "Eternal youth" http://vechnayamolodost.ru09.07.2010