Scientists in Britain have shown that stem cells extracted from human embryos can develop in the laboratory into the early forms of cells that become eggs or sperm, raising the possibility that one day eggs and sperm needed for infertility treatment could be grown in a dish.
Preliminary experiments also suggest that scientists may eventually be able to use the technique to create a supply of eggs for cloning.
But the more immediate benefit of the work could be a better understanding why some men and women do not create their own sperm or eggs and whether toxic chemicals in the environment may play a role, one of the researchers said before the start of the annual conference of the European Society of Human Reproduction and Embryology. The findings were scheduled to be presented yesterday.
"It may allow us to investigate the very earliest processes of how a human [ovary and testis] develops," said Harry Moore, a professor of reproductive and developmental medicine at Sheffield University in England.
Many scientists believe that chemical pollutants, such as pesticides, that mimic the action of hormones, might interfere with human development at the stage where eggs and sperm -- called germ cells -- are forming and that this disruption may cause birth abnormalities, infertility and possibly cancer.
"By developing suitable tests with embryonic stem cells as they differentiate into germ cells we can investigate the action of these chemicals in the laboratory," Moore said.
Stem cells are the master cells of the body, appearing when embryos are just a few days old and developing into every type of cell and tissue in the body, including sperm and eggs.
Scientists can study the stem cells by extracting them from the embryo. If the researchers create the embryo by cloning a cell from a patient, any resulting cells would be a genetic match to the patient.
The cloning technique, called cell nuclear replacement, involves emptying out the genetic material in an egg and replacing it with the genetic material of another cell, say a skin cell taken from an adult. Instead of being fertilized by sperm, the new reconstituted egg is then bathed in chemical nutrients and electrocuted to shock it into dividing. It then evolves into an embryo, from which stem cells can be extracted.
"We would need to prove that sperm or eggs produced in this way were safe before we could contemplate using them to treat patients," Moore said.
Other experts said the advance from the University of Sheffield could also raise some ethical issues.
"It opens new and challenging possibilities because the technique can be used to generate eggs from a man's [adult] cells, gay couples could have children genetically related to both,'' said Anna Smajdor, a medical ethicist at Imperial College in London.
Chinese President Xi Jinping (習近平) is to visit Russia next month for a summit of the BRICS bloc of developing economies, Chinese Minister of Foreign Affairs Wang Yi (王毅) said on Thursday, a move that comes as Moscow and Beijing seek to counter the West’s global influence. Xi’s visit to Russia would be his second since the Kremlin sent troops into Ukraine in February 2022. China claims to take a neutral position in the conflict, but it has backed the Kremlin’s contentions that Russia’s action was provoked by the West, and it continues to supply key components needed by Moscow for
Japan scrambled fighter jets after Russian aircraft flew around the archipelago for the first time in five years, Tokyo said yesterday. From Thursday morning to afternoon, the Russian Tu-142 aircraft flew from the sea between Japan and South Korea toward the southern Okinawa region, the Japanese Ministry of Defense said in a statement. They then traveled north over the Pacific Ocean and finished their journey off the northern island of Hokkaido, it added. The planes did not enter Japanese airspace, but flew over an area subject to a territorial dispute between Japan and Russia, a ministry official said. “In response, we mobilized Air Self-Defense
CRITICISM: ‘One has to choose the lesser of two evils,’ Pope Francis said, as he criticized Trump’s anti-immigrant policies and Harris’ pro-choice position Pope Francis on Friday accused both former US president Donald Trump and US Vice President Kamala Harris of being “against life” as he returned to Rome from a 12-day tour of the Asia-Pacific region. The 87-year-old pontiff’s comments on the US presidential hopefuls came as he defied health concerns to connect with believers from the jungle of Papua New Guinea to the skyscrapers of Singapore. It was Francis’ longest trip in duration and distance since becoming head of the world’s nearly 1.4 billion Roman Catholics more than 11 years ago. Despite the marathon visit, he held a long and spirited
The pitch is a classic: A young celebrity with no climbing experience spends a year in hard training and scales Mount Everest, succeeding against some — if not all — odds. French YouTuber Ines Benazzouz, known as Inoxtag, brought the story to life with a two-hour-plus documentary about his year preparing for the ultimate challenge. The film, titled Kaizen, proved a smash hit on its release last weekend. Young fans queued around the block to get into a preview screening in Paris, with Inoxtag’s management on Monday saying the film had smashed the box office record for a special cinema