Role of woman in procreation could be thing of the past

Motherless babies might be a thing of the future as scientists discover a method of creating live offspring without the need for a female egg. A group of researchers from the University of Bath, in the United Kingdom, made this discovery that rewrites over 200 years of biology and can lead to babies being born from two men.

This landmark stride can also eradicate infertility among women, help those who have reached menopause conceive and also ensure endangered species continue to reproduce.

The scientific technique upon which this discovery was based has seen fit and healthy mice  created, which have further birthed up to three generations of healthy young ones. At this rate, scientists believe humans will be able to produce offspring without need for ova in the next five years.

This research was based on the fact that it has always been perceived that during conception, the ovum, sparks a trigger in the sperm, the changes required to make a baby.

The ovum does this because it has the type of cell division that only carries forward half the chromosomes that fuse with another half of chromosomes from the sperm to create a full genetic cell (which has half the DNA from the father and half the DNA from the mother). The team from the University of Bath, led by Dr Tony Perry, has shown that embryos, life created after sperm and ovum fusion, can be created by any cell that carries all the chromosomes, which means any cell in the human body can be fertilised by a sperm.

The discovery hints that ovum may not be unique in their ability to form embryos with sperms and that skin and other cells in the body could take their place. At the start of this experiment, scientists described how they took  eggsfrom mice and used chemicals to trick them into developing as if they had been fertilised. These unusual embryos, known as parthenogenotes, behave much like skin cells and other cells in the body.

The scientists next injected sperm into the embryos and found that, rather than dying, they developed normally and, when transferred into female mice pups. This showed that normal egg fertilisation is not the only way to mature a sperm into the form needed to make all the tissues in the body.

CHILDREN OF MEN

The research showed a success rate of 24 per cent, which is better than the success rate of cloning like in the Dolly The Sheep Project. The mouse gave birth to young ones which further delivered healthy young ones and went on to show that the procedure did no harm to the animals. The scientists hope to replace eggs with skin cells in the near future.

Another team at Kyushu University in Fukuoka, Japan, led by Katsuhiko Hayashi, had a different approach to this theory and achieved the same results of live offspring without female eggs. The team took cells from the tail of a female mouse and, using a well-established technique, turned them into induced pluripotent stem cells-cells that continue to divide and form various cell types.

These cells were further placed in a brew of specially selected compounds including tissue taken from ovaries of mice foetuses to encourage them to mature into egg cells. These egg cells were fertilised by sperm from a male mouse, implanted into the uterus of a female mouse and produced viable offspring.

These experiments and their results are a tremendous advancement in science and will help us understand how eggs develop and learn more about the effects of genetic mutations on fertility. They raise the possibility that these techniques could allow women whose fertility has been wiped out by cancer drugs or radiotherapy to have their own children.

Making eggs can be a powerful tool for curbing infertility. One can make unlimited eggs from other cells like skin cells and use them for conception. It can assist women who have low egg count, those who become less fertile with age, menopausal women and those whose ovaries have been damaged, for example, by cancer treatment.

The technology would also pave the way for male couples to have embryos made by fusing a skin cell from one man with the sperm of another. An embryo could even be made by merging a skin cell with sperm from the same man.  Although this would prove to be a technical challenge due to presence of Y-chromosome in both male parties, this chromosome can still be removed without disrupting the process.

With this possibility, a man could even fertilise his own cells to produce offspring containing a mixture of genes inherited from him and his parents.

Perhaps more immediately, the research might help conservationists to maintain populations of endangered animals by giving them an alternative way to make embryos from rare creatures that can be carried to term in surrogate mothers.

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Ethical questions

Make no mistake, before all this can be put to clinical trials, a lot needs to be overcome first as far as hurdles go; as the experiments were being conducted, it was not clear why not all the fertilised eggs developed into embryos. The Bath University Project had a 24 per cent success rate, while Hayashi’s group fertilised 1,348 embryos but only eight pups were born. This is still a very low success rate to implement in human trials. It was also noted among Hayashi’s team that the mother mouse ate two pups born out of this experiment possibly after detecting an abnormality in them. Foetal tissue was also needed in the cocktail used to push the eggs to maturity; this is a very sensitive part with regard to scientific ethics. 

Breakthrough

Regardless of all these bottlenecks, this has been described as a scientific and technical tour de force that will help us to understand the fertilisation mechanism and cure infertility.