Science Simplified 3/4/23

By Reagan Oliver, Staff Writer

The lab rat room is steaming up as scientists have created the first mouse to have two fathers. 

Katsuhiko Hayashi of Kyushu University and Osaka University in Japan led a team of scientists to create a baby mouse by taking the sperm of one male mouse and turning the stem cells of the other male into female cells. To accomplish this, the scientists took skin cells from the male mices’ tails, transforming them into induced pluripotent stem cells. 

This type of cell has the ability to develop in multiple different cells, making it the perfect blank canvas for scientists to alter. Then, they used a specialized drug to convert the male stem cells into female cells, which then produced a functional egg. 

Those eggs were fertilized and placed into female mice for their gestation period. They fertilized 630 eggs, but only seven grew into living mouse pups. These pups grew normally and were able to reproduce. 

This success now introduces the idea of expansion to make this possible for humans. Yet, this process is still far from human application since only a few mouse embryos from the experiment were born alive, and it is still being determined if the same technique would be possible on human cells. 

“It’s a very clever strategy that’s been developed for converting male stem cells to female stem cells… It’s an important step in both stem cell and reproductive biology,” Diana Laird, a stem cell and reproductive expert at the University of California San Francisco, stated. 

The potential for replicating the process in larger mammals is still unknown, but it opens up the potential for further studies on the matter.