Scientists have successfully cloned a mouse for two decades, but their latest experiment has revealed a genetic ‘dead end’ to mammal cloning. Researchers in Japan created over 1,200 mice from a single original donor by serially cloning and re-cloning the animals for 57 generations. However, the team discovered that the mice accumulated so many genetic mutations that they died just one day after birth.
The study began with a single female mouse cloned in 2005, followed by 57 more generations of cloning and re-cloning. Initially, the success rates improved with each generation, but eventually, the mice began to die due to accumulating genetic mutations. The researchers found that even those carrying mutations lived normal lifespans until the 58th generation.
To test their theory, the team mated female mice from different generations with normal male mice and observed a gradual increase in litter sizes when combining healthy offspring. This suggests that mammal species can tolerate genetic mutations and still reproduce, supporting the idea that sexual reproduction is essential for long-term survival. The study’s findings reaffirm the importance of sexual reproduction in maintaining mammalian fitness.
Note: I simplified the text by removing complex sentence structures, technical terms (except for necessary explanations), and focused on conveying the main ideas and key discoveries of the study.
Source: https://www.sciencealert.com/dead-end-radical-20-year-study-reveals-genetic-cloning-hits-a-limit