The growth of immature egg cells from old mice in the ovarian structures of young mice can turn signs of aging in the egg cells 1 .

"You can imagine this like a five-star anti-aging spa for the old egg cells," says Rong Li, cell biologist at the National University of Singapore (NUS), who has participated in a study that describes the results.

When the rejuvenated egg cells were fertilized, the probability that the resulting embryos produced healthy offspring was almost four times higher than in egg cells that were matured in an old environment. The results were published in Nature Aging today.

Animated Sequence of the Procedure for the Creation of Reconstructed chimera follicle.

In the ovaries of mammals, structures that are known as follicles, a ripening egg cell that Oocyte . After development, these are released as egg cells that are ready for fertilization. With age, however, Number and quality of the oocytes from . Researchers have examined the role of aging the oocytes in the event of infertility 2 Haiyang, also a cell biologist on the NUS, focused on aging the follicles.

The latest study offers "the first solid, strong evidence" that Follicles can improve the quality of ripening egg cells, says Suzannah Williams, ovarian biologist at the University of Oxford, UK. You have "done a fantastic job".

old to young

The researchers exchanged oocytes of 14 -month -old mice that were about to become sterile, against which in the follicles of 2 months old mice that were in their reproductive highlight - and vice

they found that the quality of old oocytes improved when they were bred in young follicles, compared to those who were matured in old follicles. In particular, after treatment with young tissue, the oocytes had less chromosomal anomalies, improved mitochondrial function and their gene expression and metabolite production better profiled according to the patterns of young oocytes.

In the meantime, young oocytes that were bred in old follicles showed

increased signs of aging.

The researchers fertilized the egg cells and transferred them to surrogate mothers. Embryos that came from rejuvenated oocytes had significantly higher chances of producing a descendant than old oocytes that were bred in old follicles. Nevertheless, the success rate did not reach the descendants that came from young oocytes that were grown in young follicles.

The results indicate that aging the oocytes is partially reversible and that the surrounding cell environment plays an important role in the process, says Li.

more connections

The researchers took a closer look at what could drive the rejuvenation of the oocytes. Tunnel -like structures that combine oocytes with follicles and are known as transzonal projects (TZPS) convey important molecules for the nutrient supply of the oocytes. The researchers found a higher density of TZPS in old oocytes that were encapsulated in young follicles, compared to those who were encapsulated in old follicles.

If the results can be transferred to humans, Li suggests that this could lead to cell therapies that improve the quality of egg in older people.

However,

Williams explains that this translation will be difficult because it is challenging to obtain sufficient donor tissue and to breed it in the laboratory long enough. Nevertheless, she says: "It is a concept of concept".