Biotechnology has just taken a surprising step forward with the creation of genetically modified mice, featuring thick, golden fur reminiscent of woolly mammoths. These rodents, designed by Colossal Biosciences, could pave the way for the "de-extinction" of these extinct giants.
The woolly mouse was designed to incorporate genetic modifications related to key mammoth traits.
Credit: Colossal Biosciences
This breakthrough is part of an ambitious project aiming to recreate woolly mammoths by 2028. By manipulating genes related to fur and fat metabolism, scientists hope to adapt these animals to extreme cold. Mice, with their rapid gestation, serve as a model for testing these genetic modifications before applying them to Asian elephants, the closest living relatives of mammoths.
Genetics at the service of de-extinction
To create these "woolly mice," researchers modified seven genes, including six related to fur texture, length, and color. These genes were selected by comparing the genomes of mammoths and Asian elephants. The modified mice exhibit fur three times longer than that of standard lab mice, as well as wavy hair, characteristic of mammoths. This approach relies on cutting-edge gene-editing techniques, such as CRISPR, allowing for the precise targeting of multiple genes simultaneously.
Scientists have also targeted a gene regulating fat metabolism, essential for survival in icy climates. Although the effects of this modification are not yet clearly visible, it could play a role in cold adaptation.
These experiments demonstrate that it is possible to integrate multiple genetic mutations simultaneously, a significant technical achievement. Researchers have used methods allowing the modification of multiple DNA sites in a single operation, thereby speeding up the process of validating genetic hypotheses. This step marks an important validation for the woolly mammoth de-extinction project envisioned by Colossal Biosciences.
Technical and ethical challenges
While woolly mice represent a major scientific advancement, numerous technical and ethical hurdles remain before mammoths can be resurrected. Elephants, unlike mice, have a gestation period of 22 months. Additionally, their sexual maturity is delayed, making experiments lengthy. Moreover, assisted reproductive technologies for elephants are still underdeveloped, limiting the possibilities for large-scale genetic manipulation.
On the ethical front, the manipulation of elephants, a threatened species with high intelligence and sociability, raises significant questions. Experiments on these animals could be seen as contrary to their well-being, especially given their complex social structures. Furthermore, the financial and scientific resources devoted to this project could be redirected toward protecting currently endangered species, sparking debates among conservation experts.
Finally, the reintroduction of hybrid mammoths into modern ecosystems poses major ecological questions. Although Colossal Biosciences claims that these animals could help restore Arctic grasslands by compacting snow and promoting vegetation growth, the long-term impacts remain uncertain. Critics argue that ecosystems have evolved since the extinction of mammoths, and their reintroduction could disrupt the current balance.
These reflections show that de-extinction is far from being a simple genetic question but also involves environmental and moral considerations.
Article author: Cédric DEPOND