Japan Team Creates Offspring Using Eggs From Male Mice Cells

A team of Japanese researchers has succeeded in creating mouse offspring from eggs made using induced pluripotent stem (IPS) cells created from male mice, the first time in the world that eggs were produced from cells taken from male mammals, Osaka University Prof. Katsuhiko Hayashi led the team and published the results in the British journal Nature, Jiji Press reported.

Photo Insert: The technology enables the increasing of X chromosomes. It “may be useful in developing treatment for Turner syndrome,” in which one of the two X chromosomes in women’s cells is missing.

The sexes of mice and humans are determined by the combination of X and Y chromosomes, with “XY” being male and “XX” female. Hayashi’s team focused on the fact that the Y chromosome in male cells disappears with age, leaving the cells with a single X chromosome.

The team cultured iPS cells created from male mice cells over several generations to produce cells without the Y chromosome, and then made them into cells with two X chromosomes using a special compound.

The XX cells were grown into egg cells and fertilized in vitro with sperm from other male mice.

A total of 630 such fertilized cells were then implanted in the uterus of female mice, resulting in the births of seven mice, all of which were later confirmed to have grown up. Palestinian scientists have also tried to develop a human foetus from skin cells of males.

Hayashi said that the technology enables the increasing of X chromosomes. It “may be useful in developing treatment for Turner syndrome,” in which one of the two X chromosomes in women’s cells is missing, he said.

But many challenges remain in applying the technology to humans. It is expected to take about 10 years before technology to create human egg cells from iPS cells is developed.

Making human eggs from iPS cells also raises ethical questions. “It is researchers’ responsibility to examine the safety of technology, but it is up to society to decide how to use it,” Hayashi said.

WEEKLY FEATURE : MVP Group Keeps Lights On During Pandemic