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First human eggs grew in laboratory

    Abdulaziz Sobh
    By Abdulaziz Sobh

    Categories: Science

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    First human eggs grew in laboratory
    Human ovules have been cultured in the laboratory for the first time, according to researchers at the University of Edinburgh.

    The team says the technique could lead to new ways of preserving the fertility of children receiving cancer treatment.

    It is also an opportunity to explore how human eggs develop, much of which remains a mystery to science.

    The experts said it was an exciting development, but that more work was needed before it could be used clinically.

    Women are born with immature ova in their ovaries that can develop completely only after puberty.

    They have taken decades of work, but scientists can now grow eggs to maturity outside the ovary.

    It requires careful control of laboratory conditions, including oxygen levels, hormones, proteins that stimulate growth, and the environment in which eggs are grown.

    'Very exciting'
    But while scientists have shown that it is possible, the approach published in the journal Molecular Human Reproduction still needs refinement.

    It is very inefficient with only 10% of the eggs completing their trip to maturity.

    And the eggs have not been fertilized, so it is not known how viable they are.

    Professor Evelyn Telfer, one of the researchers, told the BBC: "It is very exciting to get proof of the principle that it is possible to reach this stage in human tissue.

    "But that has to be mitigated by all the work necessary to improve the culture conditions and test the quality of the eggs [eggs].

    "But apart from any clinical application, this is a breakthrough to improve understanding of the development of the human egg."
    The process is very controlled and synchronized in the human body: some ovules mature during adolescence, others more than two decades later.

    An egg needs to lose half of its genetic material during development, otherwise, there would be too much DNA when fertilized by a sperm.

    This excess is poured into a miniature cell called a polar body, but in the study, the polar bodies were abnormally large.

    "This is a concern," said Professor Telfer. But it is one that believes that it can be addressed by improving technology.

    The work with mouse eggs, which was nailed 20 years ago, showed that the technology could be used to produce live animals.

    Matching this achievement in human tissue could eventually be used to help children who have cancer treatment.

    Cancer option
    Chemotherapy and radiation therapy can make you sterile.

    Women can freeze mature ovules, or even embryos if they are fertilized with sperm from the couple, before starting treatment, but this is not possible for girls with childhood cancers.

    For the time being, the tissues of the ovary can be frozen before treatment, which then ripens again years later if the patient wants to have his own children.

    But if there are abnormalities in the frozen sample, doctors will think it is too risky.

    Being able to produce eggs in the laboratory would be a safer option for those patients.

    Mr. Stuart Lavery, a consultant gynecologist at Hammersmith Hospital, said: "This work represents a real breakthrough in our understanding.

    "Although still in small quantities and requiring optimization, this preliminary work offers hope for patients."

    It would be legal to fertilize one of the eggs made in the laboratory to create an embryo for research purposes in the United Kingdom.

    But the team in Edinburgh does not have a license to carry out the experiment. They are discussing whether to apply to the embryo authority for one or collaborate with a center that already has one.

    Professor Azim Surani, director of germline research at the Gurdon Institute at the University of Cambridge, said: "Molecular characterization and chromosome analysis are necessary to show how these eggs compare to normal eggs.

    "It could be of interest to test the development potential of these ovules in culture in the blastocyst stage, trying IVF."