Scientists just created female clones of male mice

Scientists have successfully transformed male mouse embryos into females for the first time, using a CRISPR-based technique to remove the Y chromosome from male cells. This groundbreaking research, conducted by a team from Japan's University of Yamanashi and Riken BioResource Research Center, could revolutionize our understanding of reproduction.

According to Takashi Ishiuchi, one of the lead researchers, this discovery could change the way scientists approach reproduction and potentially help save endangered species. The researchers were inspired by the Okinawa rubble goby, a fish that can change its sex when necessary. Their work, published in a preprint paper on bioRxiv, has not yet undergone peer review.

The technique, called Y-CUT, involves targeting and cutting a section of the Y chromosome responsible for ensuring male sex determination. When applied to early-stage mouse embryos, it results in XO females, which are healthy and fertile. The researchers also successfully created female clones of male mice using standard cloning methods, followed by Y-CUT treatment.

This approach could have significant implications for conservation efforts and genetic engineering, as well as for studying sex chromosomes. However, the method currently requires hollowed-out egg cells, which must come from closely related females, limiting its applicability to species with only female survivors. Nonetheless, complementary technologies, such as the recent development of turning male mouse cells into egg cells, could enhance the Y-CUT technique's potential.