Testicular tissues taken from young monkeys, which are then frozen and grafted into their bodies later in life, can give birth to sperm and allow them to live young, scientists said.
Although this approach has already been successful in other animals, including mice, this is the first time a primate has produced offspring. The team reported that the born Rhesus macaque baby is a healthy woman named Grady, after the words "derived from the transplant" and "baby".
This development has been hailed as a major breakthrough that could have profound implications for young boys with cancer.
Medical treatments such as chemotherapy and radiation can damage testicular stem cells and affect sperm production. Although men can keep their sperm stored before undergoing such treatments, boys who have not yet gone through puberty do not yet produce sperm.
"This breakthrough is an important step towards providing young cancer patients around the world with a chance to start a family," said Professor Kyle Orwig, co-author of the Faculty of Medicine's Study of Medicine. 39, University of Pittsburgh.
By writing in the journal Science, Orwig and his colleagues reveal how they took the testicles of five Rhesus macaques in two stages. One of them was removed before the animals entered puberty, with the tissue cut into small pieces and frozen. The other was removed five to seven months later, at the approach of puberty, with the tissue also carved.
A few hours later, this fresh tissue and the tissue taken months earlier were reimplanted into the monkeys, three of each type of tissue being placed under the skin on the backs of the animals and one of each type grafted under the skin of their scrotum. .
Months later, it was found that both types of tissue had developed and produced sperm.
The team took the sperm produced on a monkey after the implantation of tissues previously frozen under the skin of his scrotum. This spermatozoon was then used to fertilize the eggs of female Rhesus monkeys. Of the 138 eggs used, 16 embryos were produced. Of the 11 embryos implanted in female macaques, a baby was born by cesarean section: Grady.
Experts quickly welcomed the news, stressing that it was urgent to find ways to preserve the fertility of young boys being treated for cancer.
"Currently, we can only preserve male fertility by freezing sperm. Therefore, this option is not feasible for boys under the age of 13 because they have not yet gone through puberty and have begun to make puberty, "said Allan Pacey andrology at the University of Sheffield.
Pacey and others said it will take some time before such an approach is available for young patients. Further research is needed to show that it works in humans and is safe.
The team at the origin of the latest research points out that in humans, the testicles would not be removed, so it is necessary to continue the work to be sure that the approach would work. They add that this may not be appropriate for patients where there is a risk that the tissue removed may contain cancer cells.
Daniel Brison, a professor of clinical embryology at the University of Manchester, said the study was an important proof of concept, but questions remained.
"The study is limited by the fact that only one animal is born and that more in-depth preclinical studies are now needed to address the long-term health of individuals conceived by this method," he said. he declares.