Parthenogenic stem cells
Scientists have grown stem cells with a half set of chromosomes
Israeli and American biologists have created unusual human stem cells that contain not the usual "double" set of chromosomes, but only one set of all DNA strands, which makes them look like germ cells, according to an article published in the journal Nature (Sagi et al., Derivation and differentiation of haploid human embryonic stem cells).
"The main advantage of these haploid cells is that their genes are much easier to edit. In ordinary diploid cells, it is extremely difficult for us to track the biological significance of single mutations in genes, since the second copy of this DNA section does not change and works as a "backup copy," said Ido Sagi from the Hebrew University of Jerusalem (Israel).
Haploid (left) and diploid (right) cells
(picture from the press release of Columbia University Medical Center
Scientists Generate a New Type of Human Stem Cell That Has Half a Genome – VM).
Sagi and his colleagues created these unusual stem cells, which they call "parthenogenesis cells," by studying what happens to eggs if they are forced to divide artificially, mimicking the signals that arise when they are fertilized by a sperm.
The inclusion of division systems, as experiments by Israeli biologists have shown, leads to the formation of many cells containing not two, but only one set of chromosomes and genes. Some of them, according to Saga and his colleagues, have turned into full-fledged stem cells capable of turning into "blanks" of most adult body tissues.
Scientists have identified two types of such cells and learned how to control their reproduction, separating stem cells that spontaneously turned into "ordinary" diploid cells from their haploid "cousins".
Such cells have several advantages over "ordinary" embryonic stem cells. In particular, they can be used to quickly search for mutations and create individualized cell cultures necessary for the treatment of type I diabetes, blindness or other diseases, with the development of which certain tissues die or degenerate.
In addition, such cells, thanks to a single set of chromosomes, can be naturally used to solve reproductive problems – infertility treatment or, for example, for artificial insemination.
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17.03.2016