A genetically modified lab mouse with striking mammoth-like traits could be a small but significant step toward bringing back the extinct woolly mammoth. Scientists at Dallas-based Colossal Biosciences have successfully engineered a “woolly mouse” that exhibits physical characteristics similar to the long-extinct giant, including wavy, light-colored fur and elongated whiskers.
The breakthrough, announced in a press release by Colossal Biosciences, is part of the company’s larger effort to use genetic engineering to revive extinct species, including the woolly mammoth, the dodo, and the Tasmanian tiger. The woolly mouse provides researchers with a model to test the effectiveness of gene-editing techniques before applying them to larger mammals, such as elephants, which are the mammoth’s closest living relatives.
Genetic Engineering and the Woolly Mouse
To create the woolly mouse, scientists at Colossal Biosciences identified genetic differences between woolly mammoths and their closest living relatives, the Asian elephants. They then targeted 10 specific genetic variants related to hair length, texture, thickness, color, and body fat, corresponding to known DNA sequences in lab mice. Using cutting-edge gene-editing techniques, they successfully introduced these traits into laboratory mice, resulting in genetically engineered rodents with visibly woolly coats.
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Among the key genes modified was FGF5 (fibroblast growth factor 5), which influences hair growth cycles, leading to the longer, shaggier fur characteristic of mammoths. Scientists also edited genes associated with hair follicle development, melanin production (MC1R), and body weight regulation. In total, eight simultaneous gene edits were made across seven genes in the test mice.
Significance of the Research
Dr. Beth Shapiro, Colossal Biosciences’ chief science officer, described the project as an “important step toward validating our approach to resurrecting traits that have been lost to extinction.” She explained that proving genetic modifications work in smaller mammals like mice builds confidence that similar edits could one day be successfully implemented in elephants to create mammoth-like hybrids.
“This research enables us to test our hypotheses about how specific genes influenced mammoth adaptations to cold environments,” Shapiro stated. “It brings us one step closer to understanding how to reintroduce these traits in larger mammals.”
Skepticism and Ethical Concerns
Despite its technical success, the woolly mouse project has sparked debate among scientists and ethicists. Some experts argue that the genetic modifications, while impressive, do not yet prove that these traits would provide cold resistance or other adaptations crucial for mammoth survival.
Robin Lovell-Badge, head of the Stem Cell Biology and Developmental Genetics Laboratory at The Francis Crick Institute in London, expressed skepticism about the study’s real-world applications. “We now have some cute, hairy-looking mice, but there is no evidence yet that they exhibit mammoth-like physiological or behavioral traits necessary for Arctic survival. This does not necessarily bring us closer to engineering a mammoth-like elephant.”
Another concern is whether creating partial approximations of extinct species truly constitutes de-extinction. Dr. Tori Herridge, a paleontologist at the University of Sheffield, warns that unless all necessary genetic edits are made, scientists are only producing crude approximations of extinct creatures. “We are never going to ‘bring back’ a mammoth,” Herridge said. “At best, we will create an elephant engineered to resemble a mammoth. The reality is more complex than simply inserting mammoth genes into an elephant.”
Colossal’s Vision: From Mice to Mammoths
Founded in 2021 by entrepreneur Ben Lamm and Harvard geneticist George Church, Colossal Biosciences has raised $435 million to fund its ambitious de-extinction projects. The company plans to use similar genetic engineering techniques to recreate woolly mammoth-like elephants capable of thriving in the Arctic tundra.
One of the primary motivations behind reviving the mammoth is to combat climate change. Colossal argues that restoring mammoth-like creatures to the Arctic ecosystem could help slow permafrost thawing by compacting snow and grass, which insulates the ground. This, in turn, could reduce the release of carbon trapped in permafrost, mitigating greenhouse gas emissions.
Colossal has previously announced that it aims to introduce the first woolly mammoth calves by 2028. The woolly mouse experiment serves as a stepping stone toward that goal, providing valuable insights into gene-editing accuracy and efficiency before attempting to modify elephants.
Challenges and the Road Ahead
While gene-editing in mice is relatively straightforward, applying the same techniques to elephants presents significant challenges. Unlike mice, elephants have long reproductive cycles, making genetic experiments more difficult and time-consuming. Furthermore, assisted reproductive technologies for elephants are far less advanced than for other animals such as cattle or mice.
Dr. Rob Taft, a principal scientist at The Jackson Laboratory, praised the woolly mouse experiment as “an innovative approach to understanding extinct animal physiology.” However, he questioned how Colossal would translate its research to elephants. “Editing a few genes in a mouse is one thing; editing an elephant genome and successfully breeding a modified elephant is a much greater challenge,” he noted.
Public and Scientific Debate on De-Extinction
The concept of de-extinction has long fascinated scientists and the public alike. Movies like Jurassic Park have popularized the idea of reviving extinct species, but real-world applications remain controversial. Some experts argue that the enormous financial investment in de-extinction could be better spent on conserving endangered species currently facing extinction.
Moreover, raising and breeding genetically modified hybrid animals poses ethical and logistical concerns. Using living elephant surrogates to gestate mammoth-like embryos raises questions about the welfare of surrogate mothers and the potential impact on existing elephant populations.
Despite these concerns, Colossal remains committed to its vision. The company sees the woolly mouse not just as a proof of concept but as a tangible step toward its long-term goal of reintroducing mammoth-like creatures to the wild.
Conclusion
The creation of a woolly mouse with mammoth-like traits represents an exciting advance in genetic engineering and de-extinction research. It provides scientists with an opportunity to refine their techniques before attempting more complex modifications in larger animals. However, significant hurdles remain before Colossal Biosciences can achieve its ambitious goal of bringing back the woolly mammoth.
As research continues, the debate surrounding de-extinction—its feasibility, ethics, and ecological impact—will persist. While the woolly mouse may be small, its implications for the future of genetic engineering and conservation are enormous. Whether this research ultimately leads to a true resurrection of extinct species or remains an intriguing but impractical scientific endeavor remains to be seen.
