Researchers are breeding a functioning egg

In the future, human life can be bred from stem cells in the laboratory?

05/10/2012

Japanese scientists succeeded in breeding healthy mice from stem cells. With this, they have come a step closer to the human dream of creating human life in the laboratory. After all, the researchers were able to win egg cells from stem cells, from which then developed artificial insemination healthy, fertile mice in the womb. The Japanese study could reveal new ways for infertile couples.

Obtaining Eggs from Stem Cells Forward-Looking?
The researchers of the Kyoto University succeeded in a mouse attempt to obtain healthy, functional oocytes from stem cells. These were then artificially fertilized. In the womb, the "artificially" bred mouse babies developed like mouse embryos, which were produced in the normal way. The Japanese researchers could not only enjoy healthy mice, but also that the animals themselves were capable of reproduction. Already last year there had been similar attempts with sperm.

Amander Clark, a stem cell biologist at the University of California, considers the Japanese study results a great success and believes in a "continuing impact on reproductive cell biology and genetics," she told Science magazine.

Oocytes derived from embryonic and induced pluripotent stem cells
Study leader Mitinori Saitou and his team use embryonic stem cells for their experiments, which are obtained from embroons and are able to differentiate into any kind of cell type. On the other hand, the Japanese researchers used so-called induced pluripotent stem cells (iPS cells), which come from already developed body cells and are therefore ethically less questionable. iPS cells can differentiate into numerous cells. Both cell types were grown in cultures with a cocktail of proteins to create primordial cell-like cells. Urine germ cells can develop into eggs and sperm. To obtain egg cells or oocyte progenitors, the researchers mixed the primordial germ cells with fetal ovarian cells, which were to form ovaries and were planted on natural ovaries of living mice. After a period of four weeks and four days, the primordial germ cells in oocytes would have differentiated, reports "Science". The scientists took the eggs, fertilized them in vitro, and used the resulting embryos for surrogate mothers. After about three weeks, normal and apparently healthy mice were born, as the scientists report in the journal.

Both cell types developed healthy and fertile mice that continued to multiply. According to the Japanese researchers, although the success rate is still relatively low, the study results could be used as a basis for the development of human oocytes in the laboratory. "The study has provided critical evidence that oocytes can be obtained from induced pluripotent stem cells," Clark told Science. In humans, the results for the production of egg cells from iPS cells from infertile women could be used, the expert added.

Sperm cells derived from embryonic stem cells
Already last year, Japanese scientists succeeded in cultivating viable sperm cells in the laboratory. At that time, the researchers took testicular tissue from mice and stimulated the early stages of the sperm contained in the tissue for maturation. The mature sperm were then fertilized egg cells, from which healthy mice babies emerged. "The work provides evidence that primordial germ cells derived from embryonic stem cells can become viable germ cells," Clark told Science at the time, describing the results as "critical progress in our basic understanding of the principles of germ cell development." (Ag)

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Picture credits: Andreas Dengs, www.photofreaks.ws