## Japanese Cloning Study Hits Biological Wall: Mammals Cannot Be Cloned Infinitely
A landmark Japanese study has delivered a sobering verdict on the limits of reproductive cloning: mammals cannot be cloned indefinitely. This fundamental biological barrier was revealed through a two-decade-long experiment that created over 1,200 cloned mice, all derived from a single original donor.

The research, conducted by a team in Japan, systematically tracked the viability of clones across multiple generations. Starting with one mouse, scientists used its cells to create clones, then used those clones to create the next generation, and so on. While initial generations were successful, the cloning efficiency plummeted after repeated cycles. The experiment provides the first large-scale, long-term evidence that the cumulative errors and epigenetic damage inherent in the somatic cell nuclear transfer (SCNT) process impose a hard limit on serial cloning.

The findings carry significant implications for biotechnology, agriculture, and conservation efforts that have considered cloning as a tool for species preservation or genetic replication. It signals a major constraint on using cloning as a method for creating infinite genetic copies, forcing a reevaluation of its long-term feasibility. The study shifts the scientific conversation from technical possibility to inherent biological limitation, underscoring that even advanced technology cannot circumvent certain natural reproductive boundaries.
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- **Source**: Japan Times
- **Sector**: The Lab
- **Tags**: cloning, genetics, biotechnology, reproductive science, mice study
- **Credibility**: unverified
- **Published**: 2026-04-15 06:52:22
- **ID**: 65005
- **URL**: https://whisperx.ai/en/intel/65005