A breakthrough in the field of genetics has been achieved as a Japanese researcher announced on March 8, that he has created eggs from male mice. Although, for now, the research is far from being used on humans.
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Image Source: Royal Society
On March 8 at the Crick Institute in London, at the third international summit on human genome editing, a Japanese researcher Professor Katsuhiko Hayashi, from Osaka University, revealed that his team of researchers has made eggs from the cells of adult male mice.
The research has not been published yet, but the developments have been submitted to the scientific journal Nature for publication.
Prof. Hayashi, who is a globally recognized pioneer in the field, told the delegates at the summit that the research was at a very early stage. He also believed that the eggs produced were of low quality, and at this stage, the technique could not be considered suitable for use on humans.
Image Source: BBC
Technique
Hayashi and his colleagues created induced pluripotent stem cells (IPS) from the skin cells of adult male mice. Male cells in mice typically have XY chromosomes, which is similar to human males.
The team grew these stem cells in culture until some of them were observed to have lost their Y chromosomes. To promote errors in chromosomal distribution during cell division in these cells, they were treated with a compound called reversine.
The chromosomally female cells, that is, the ones having XX chromosomes, were looked for. Hayashi believed that the biggest trick to the technique was the X chromosome duplication, as they tried to establish a system for the replication of the X chromosome.
Genetic signals were provided to these induced pluripotent stem cells, which are required for the formation of immature eggs. These eggs were then fertilized with mouse sperm, and the resulting embryos were then transferred into the uterus of a female mouse.
The embryos had a low survival rate. Only seven embryos out of 630 developed into pups. However, the pups grew normally and were fertile adults.
Image Source: The Telegraph
A Vision for the future
Hayashi stated that there are many big differences between humans and mice. The technique is far from being used for humans, as it is complicated to translate such discoveries in stem cells and reproductive biology from mice to the clinic.
He also believed that the pups needed to be carefully analyzed to look for different ways in which they differed from those produced conventionally.
He added that it might take around ten years of research before the technique can be used on humans.
Keith Latham, a developmental biologist at Michigan State University, East Lansing, said the approach has significant potential applications. He also added that even if the approach is possible in humans, to make it practical and more efficient, the proportion of embryos that lead to offspring will need to be increased.
This research has the potential to provide a line of treatment for some types of infertility caused by abnormal sex-chromosomal conditions. For instance, in Turner’s Syndrome, the woman lacks a part or all of one of her X chromosomes.
Tetsuya Ishii, a bioethicist at Hokkaido University in Sapporo, Japan, believes that the research has the potential to take human reproduction to new territories, even though its human use can be seen only in the far future.
The research is promising for same-sex couples, especially males, with the aid of surrogate mothers, to have biological children together.
There can also be a possibility for a single man to become a parent and have a biological child using this research technique. This could also be used for couples where the women are not able to produce eggs.
Although, as stated by Hayashi, such techniques require more than just technical refinement, and there is a broader societal discussion regarding the implications and ethics of implementing them. He also added that if people and society accept the technology, he would be down for it.
