Sunday, November 24, 2013

Male Y chromosome is unnecessary? Are we seksmisja? - Gazeta Wyborcza

The scientist, however, argues that the role of these two genes can be used to replace (eg, move them to other chromosomes), and then the male Y chromosome becomes even unnecessary. Fortunately, just adds Dr. Ward, that a world without men would be “crazy” and the sci-fi style.

The scientist was born in Poznan, a doctorate in Poland, and now works in the School of Medicine, University of Hawaii. She is married to Professor. Steven Ward, Director of the Institute for Biogenesis (before the wedding she wore name Gaw?cka).

The results of the experiment conducted by her team describes the latest edition of the magazine “Science”. The aim of the researchers was to draw “the essence of masculinity” of the DNA chromosome Y. As it turned out, the mice are just two genes. Male mice robbed of genetic masculinity, in which only these two genes were present in the Y chromosome could still become fathers, but was needed for this technique of artificial insemination.

What exactly was this experiment?

DNA, including human, is packaged in cells acting as something similar to suitcases – are these chromosomes. In most animals, one pair of these suitcases is responsible for the sex of the individual – is called. sex chromosomes. In humans, a woman has two sex chromosomes X and Y. X and male Y chromosome determines the male gender so.

Until recently, many geneticists believed that Y is a residual entity, full of “broken” genes that have accumulated It is in the process of evolution. This was because, unlike other genes as he has only his second copy. It raisins deprived of support, which can mitigate the effects of errors or mutations. Despite this, however, the Y has different methods of repairing the damage, because in the light of recent research is the creation of very stable – has not changed much in the past 100 million years! But the fact remains – the majority of Y contained in the genetic information serves only one purpose, which is the male reproduction.

– Y chromosome is a symbol of masculinity – says Dr. Monika Ward.

In the mouse chromosome This normally contains 14 genes characteristic for each other, some are present in hundreds of copies.

Hawaiian team showed that genetically modified rodents with a Y chromosome, containing only two of the 14 genes develop normally and may beget offspring.

Dr. Ward commented: – These mice are infertile, which means that by themselves can not reproduce. We, however, have shown that they are able to wait for the offspring, if we can help them, using the specialist in vitro [ROSI method - injection into oocytes of immature sperm]. Conceived in this way, the offspring were healthy and lived as much as ordinary mice, which have not been modified.

The effectiveness of this method was much smaller than in vitro performed using sperm from a ‘healthy’ Y (9 per cent. compared to 26 per cent.).

These two genes are necessary: ??Sry, which directs the process of embryonic development of the mouse in the “masculine” side, and Eif2s3y gene, which is involved in the first stages of spermatogenesis (sperm production) .

Why such experiments?

– have shown that the loss of even huge portions of the Y chromosome in mice does not result in loss of their reproduction. It is hope for men who have so destroyed “igreki” – says scientist.

Genes whose researchers got rid of the mouse Y chromosome, but they are important – involved in the production of healthy, vibrant sperm capable of fertilization without support slides and pipettes scholars.

– This is a big step in understanding the basic biology, including human biology – said in a commentary on the work of Dr. Chris Tyler-Smith of the famous Wellcome Trust Sanger Institute.

And he added: – It is important, however, to keep in mind that other genes located on the Y chromosome are essential for the natural reproduction of the mouse, and as the authors themselves noted, these results can not be directly translated to humans, if only because it man does not have the gene Eif2s3y in his “igreku”.

– There is no doubt, however, is very surprising that so few genes is crucial for mouse masculinity – says Michael Griswold, reproductive biologist at Washington State University in Pullman. – This work is somehow frightening – he added.

But Could seksmisja

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