How to make a boy out of a girl and teach mice to sing?
Scientists have created a male without a Y chromosome
CNewsR&D based on ScienceDaily:
Sex Reversal Gene: Male Mice Can Be Created Without Y Chromosome Via Ancient Brain GeneAustralian scientists have moved one step closer to solving the mystery of mammalian sexual development – with the activation of an ancient gene, they managed to create male mice that do not have male sexual Y chromosomes.
Usually male individuals have one Y chromosome and one X chromosome, whereas female individuals have two X chromosomes. Activation of a single SRY gene, localized on the Y chromosome, at the early stages of embryo development triggers the formation of seminal glands, which entails the development of other signs of the male body.
Scientists have managed to achieve a similar effect by activating the SOX3 gene in the genitals of a developing embryo with two X chromosomes. This gene is known for its role in the development of the brain, but its participation in the sexual development of the male body has not yet been known.
In the illustration from an article in the Journal of Clinical Investigation
(Edwina Sutton Identification of SOX3 as an XX male sex reversal gene in mice and humans), from left to right:
view of external genitalia of female (XX), normal (XY) and XX-male;
their prepared internal genitalia (scale – 2 mm);
a section of the testicular tissue of a real and "almost real" male (scale – 100 microns).
Unfortunately, the synthesis of spermatozoa in XX males has not begun - this can be seen in the lower right picture – VM.
The authors also demonstrated for the first time that some patients with impaired sexual development have changes in the human version of the SOX3 gene.
For quite a long time, there has been a hypothesis that the SOX3 gene is an evolutionary precursor of the SRY gene. Judging by the data obtained by the authors, this hypothesis is not so far from the truth.
The researchers believe that the mechanism they identified in the future will help not only to understand the causes of the appearance of sexual development disorders that are quite common in human society, but will also form the basis of methods for the molecular diagnosis of such disorders (see, for example, the article on the opposite phenomenon: Chromosome Quirks: a girl with the XY –VM karyotype), as well as their treatment.
Scientists accidentally bred singing mice
ABC Magazine based on AFP materials: Japan bio-scientists produce 'singing mouse'
Japanese scientists from Osaka University accidentally bred singing mice. Initially, they crossed rodents with a modified genome among themselves, observing how certain deviations change in generations. And one of the mice, specially bred as part of the Evolved Mouse project, suddenly began to make sounds extremely reminiscent of birdsong.
The unusual mutation was fixed, and now researchers have at their disposal more than a hundred mice singing in different voices. Scientists have already noticed that mice sing differently in different environments, including when females are placed together with males. Thus, according to the Japanese, a mouse squeak or, in this case, singing, can be considered an expression of emotions. And they hope to use singing rodents to study the formation of colloquial speech in humans.
In particular, they are currently interested in the question of how the behavior of "singers" among their ordinary brethren will change and whether the former will be able to teach the latter to sing. In addition, experiments with the mouse genome will continue. "It is possible that one day we will be able to bring out Mickey Mouse," one of the project managers Arikuni Uchimura (Arikuni Uchimura) remarked half-jokingly.
Portal "Eternal youth" http://vechnayamolodost.ru
23.12.2010