# CRISPR Used to Change Gender and Clone Mice Scientists have transformed male mouse embryos into females. - **Source:** [MIT Technology Review](https://www.technologyreview.com) - **Published:** 2026-08-14 - **Topic:** [Data & AI](https://brifing.si/c/data-ai) - **Original article:** - **On Brifing:** https://brifing.si/s/6b9aac89-345c-4f20-832f-28479098f757 ## Gender Change with CRISPR Scientists have used CRISPR technology to transform male mouse embryos into females. This method involves cutting out the Y chromosome, allowing the creation of genetically identical female clones of male mice. Takashi Ishiuchi from Yamanashi University and Shogo Matoba from the Riken BioResource Research Center believe this approach could be beneficial for conservation efforts. ## Dolly and the History of Cloning Dolly, born in 1996, was the first mammal cloned from an adult cell. Scientists took the DNA from a sheep's mammary cell and transferred it into an egg cell with its nucleus removed. This embryo was implanted into a surrogate sheep, resulting in Dolly's birth. This breakthrough marked a turning point in cloning technology, making it possible to create genetic copies of animals. ## Pet Cloning Cloning technology is also used to replicate deceased pets. Celebrities like Barbra Streisand and Tom Brady have cloned their pets. This process costs tens of thousands of dollars but raises ethical concerns. Bioethicist Jessica Pierce has described dog cloning as 'the exploitation of the canine underclass.' ## Cloning for Conservation Cloning is employed to preserve endangered species. The 'frozen zoo' at the San Diego Zoo stores cells from over 1,300 species. These cells have enabled the cloning of animals like the black-footed ferret and Przewalski's horse. This method holds potential for bringing back extinct species in the future. ## Cloning Extinct Animals In 2009, Spanish researchers cloned an extinct Pyrenean ibex using skin cells cryopreserved a decade earlier. They created 439 embryos, but only one goat was born, which died minutes later due to a lung defect. This marked the Pyrenean ibex as the only animal known to have gone extinct twice. ## Colossal Biosciences and Ancient Species Colossal Biosciences aims to use ancient genetic material to bring back long-extinct species like the thylacine and woolly mammoth. So far, the company has focused on modifying the genomes of modern animals. These efforts offer hope for reviving species that have been lost to extinction. ## Human Cloning and Ethical Issues Technically, human cloning is possible, but no one has done it yet. Some have proposed the idea of 'brainless clones' for organ transplantation in the future. However, such applications raise serious ethical questions and spark debates within the scientific community. ## The Future of Cloning Cloning technology has advanced significantly over the past few decades. Scientists predict further developments and new applications in the future. However, the ethical and environmental impacts of this technology must be carefully considered. Cloning promises both an exciting and concerning future. ## Sources covering this story - https://www.technologyreview.com/2026/08/14/1141919/cloning-save-species-or-make-human-organ-sacks/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._