1 week ago
Scientists Create Fertile Female Clones From Male Mice
Scientists in Japan made female mice using cells from male mice.
Male mice usually have X and Y chromosomes.
The scientists used gene editing to remove the Y chromosome.
This left embryos with only an X chromosome, called XO.
Surrogate mice carried the embryos and gave birth to female pups.
The pups were fertile, meaning they could reproduce.
This could someday help endangered animals if no females are left.
However, only a small number of embryos became healthy mice.
Experts also said the method may not work in humans, horses, or many wild animals.
Japanese scientists created fertile female mice from male cells by removing Y chromosomes.
The team used the CRISPR-based Y-CUT technique, known as dual-sex cloning.
The cloned female mice had XO chromosomes and were born to surrogate mice.
The method could help preserve endangered species when only males remain.
The experiment’s efficiency was low, and experts questioned whether it will work in wildlife or humans.
- Who
- Scientists from the RIKEN BioResource Research Center and the University of Yamanashi, led in part by Dr Shogo Matoba.
- What
- They deliberately created fertile female mouse clones from male somatic cells by removing Y chromosomes.
- Where
- Japan, at research institutions including the RIKEN BioResource Research Center and the University of Yamanashi.
- When
- During a new experiment described in research posted on the bioRxiv preprint server.
- Why
- The technique may help preserve genetic diversity in endangered species when living females are unavailable.
Potential Conservation Benefits
Scientific Limitations and Risks
Use for endangered species
Potential Conservation Benefits
The method could create females from preserved male tissue, potentially helping species with severely limited populations or no living females.
Scientific Limitations and Risks
The experiment was conducted only in mice, and its effectiveness in other species remains uncertain.
Applicability across species
Potential Conservation Benefits
Teruhiko Wakayama said the approach would be incredibly valuable if it worked in species beyond mice.
Scientific Limitations and Risks
Linda Penfold said Y-deleted offspring are not fertile in humans and horses, suggesting the method may also fail in multiple wildlife species.
Readiness of the technique
Potential Conservation Benefits
The birth of a female clone from a male donor demonstrates that the biological concept can work deliberately.
Scientific Limitations and Risks
Efficiency remained low because only a small percentage of embryos became live, healthy mice.
Key facts
- Technique
- CRISPR-based Y-CUT, also called dual-sex cloning
- Donor cells
- Male mouse somatic cells
- Cloned mice
- Female mice with XO sex chromosomes
- Birth process
- Engineered embryos were transferred to surrogate mice
- Reproductive result
- The female clones were fertile
- Current limitation
- Only a small percentage of embryos developed into live, healthy mice
- Conservation potential
- The method could potentially create female breeding stock from preserved male tissue
Quotes
Shogo Matoba
Author of the Japanese study.
“The most exciting moment was actually when the first female clone was born from a male somatic cell.”
NDTV
Teruhiko Wakayama
University of Yamanashi scientist quoted by New Scientist.
“It would be incredibly valuable if this were successful in species other than mice.”
NDTV
Linda Penfold
Representative of SEZARC, a US-based group of zoos and conservation centres.
“Y-deleted offspring are not fertile in humans and horses, and therefore this is likely to be the case in multiple wildlife species”
NDTV










