Mouse study shows repeated cloning causes grave genetic mutations

https://www.reuters.com/business/healthcare-pharmaceuticals/mouse-study-shows-repeated-cloning-causes-grave-genetic-mutations-2026-03-24/

A total of 1,206 cloned laboratory mice were generated by the scientists from a single female donor mouse from 2005 ‌to 2025 in research conducted in Japan. There were no outward signs of trouble through the first 25 generations, but mutations subsequently began piling up until becoming fatal.