Embryo cells from skin cells

An article at ScienceDaily summarizes the findings of a research conducted at the Hebrew University of Jerusalem (HU). With this study, researchers have found a way of transforming skin cells into the three major stem cell types that comprise early-stage embryos, (embryo, placenta and extra-embryonic tissue), using mouse cells. This was achieved by using retroviruses to insert a series of genes into the skin cells.

In a different article, the author notes that human skin cells have already been tested, and were successfully transformed using the same techniques used in mouse cells. Although successful, the technique with retroviruses could cause tumors in the tissue. The next step is finding a way of altering or switching genes existing in the cells, instead of inserting new copies.

Scientists say that in the future, it could be possible to create whole human embryos out of skin cells. The findings are significant since embryonic cells can be used to model and study embryonic diseases and placental dysfunctions as well as other complications without using "real embryos" or oocytes; therefore escaping some of the ethical debates that surround the field. With this I think that humans are getting closer to find a way of creating life without even the need of sex cells.  

4-cell stage mouse embryos

'Cow Gene' Explains Failure of Cloned Genes

A recent study conducted at the University of California showed a cow gene that demonstrated why most clones fail. Cloning mammals has proven to be a challenge; however, it was just twenty years ago that Dolly the sheep was successfully cloned. Using the technique of somatic cell nuclear transfer was originally how Dolly was cloned, or rather when a nucleus from an adult cell is transferred into unfertilized egg that has had its nucleus removed, and then begins cell growth by an electric shock. Recipient mothers then carry the transferred embryos until the clones are born.

The process of cloning cattle can be used to study development in mammals, and is important technology for agriculture; however, the success rate remains very low - less than ten percent of cloned animals survive until birth. Losses of the cloned animals may be due to a variety of reasons: failure during implantation of the embryo, embryonic death in general, or the possible development of a defective placenta. However, with recent developments into why there is so much reoccurring failure, it may be possible to get to the root of the issue. Scientists used RNA sequencing in order to look at gene expression in cows that had been cloned during implantation and attempt to understand the molecular mechanisms that lead to such a high rate of failure during pregnancy.



In this study, the researchers studied tissue from cloned cow embryos--all derived from the same cell line--at 18 and 34 days of development, as well as the corresponding endometrial lining of the pregnant cows. They also used cows that were not cloned, conceived using the process of artificial insemination. By use of RNA sequencing, multiple genes were found to be expressed abnormally, that could potentially lead to the high mortality rate of cloned embryos, as well as their failure to be implanted in the uterus and to develop a normal placenta. Researchers were able to find anomalies in expression of more than five thousand genes looking at the extra embryonic tissue of those of the cloned cows by day 18. Hopefully researchers will be able to use this find to uncover more developmental issues of the cloned embryo, and eventually lead to a higher survival rate.

As much as I find cloning of genes interesting, I do wonder about the possible risk factors involved, besides those listed above. It makes me very curious to see the future of these processes, and what could potentially come out of then. I also do think that cloning of genes as a whole could be a very useful practice, especially with genes that may be correlated to positive human growth and health. I'm sure that there is a lot left to learn about the future of cloning, and I am excited to see where it goes.