Colossal Biosciences, a US biotechnology company, recently announced a breakthrough research achievement. Its research team has successfully cultivated a new type of mouse experimental subject through gene editing technology and named it "Long haired Mouse". This scientific research achievement marks significant progress in the company's plan to "resurrect" the extinct woolly mammoth.

On the 5th, the Associated Press reported that scientists simultaneously edited seven genes in mouse embryos, focusing on genes related to hair texture and fat metabolism. These characteristics are believed to be closely related to cold resistance, which is the key survival ability for woolly mammoths to adapt to the ice age. Gene editing refers to a molecular technique that causes specific changes in the genome by deleting, inserting, or replacing a segment or specific base of the genome. By using this technology, it is possible to accurately locate a certain site on the genome, cut the target DNA fragment at this site, insert a new DNA fragment, and mutate the specific site gene sequence, achieving genetic modification of the DNA sequence.

Since the announcement of the "Resurrection of Extinct Species" plan in 2021, Colossal Biosciences has continued to receive attention from the scientific community. The company identifies key characteristics of extinct species by analyzing ancient genes, and then modifies existing closely related species through gene editing technology. The birth of the "long haired mouse" marks a milestone in its "species resurrection" plan, laying the technical foundation for achieving the goal of surrogate elephants giving birth to mammoth cubs before 2028. Public information shows that the woolly mammoth was widely found on ice sheets in Europe, Asia, and North America until it became extinct about 4000 years ago.

The company stated that the experiment of cultivating "long haired mice" aims to verify the feasibility of the technology, and the next step is to turn to gene editing of embryos from Asian elephants, close relatives of mammoths. However, considering that Asian elephants are endangered species, Colossal Biosciences admits that subsequent research will need to overcome numerous regulatory barriers. Although the latest experimental results have not yet undergone peer review, they have sparked heated discussions in the academic community. Biologist Lynch from the State University of New York at Buffalo described this technology as "very cool". Scientists have been genetically engineering mice since the 1970s, but new technologies like CRISPR "make it more efficient and easy". However, Princeton, an expert at the University of Montana, questioned, "Changing the hair of Asian elephants or making them cold resistant does not mean reviving mammoths, it is just a genetic modification of existing species

Ben Lamm, co-founder and CEO of Colossal, emphasized that this "long haired mouse" is not simply a direct implantation of mammoth genes into mice, "but rather a validation of the accuracy of the company's gene editing technology through deep computational analysis to identify genes related to mouse hair length, thickness, color, texture, and metabolic characteristics." Lamm pointed out, "By editing multiple cold resistant traits in the evolution path of mammoths into existing model species, we have demonstrated the ability to reproduce complex gene combinations that naturally take millions of years to form." "Woolly Mouse is not just an engineering feat, which confirms that our targeted and precise editing method based on very deep computational analysis is indeed effective

It is reported that the survival rate of 38 modified mice in Colossal is equivalent to that of ordinary mice. These mice will naturally age, and the company has no plans to sell or reproduce them. In addition, Ram said that the same method may one day help humans fight against diseases. So far, the company has spun off two healthcare companies.