Colossal Achieves Milestone with Woolly Mouse, Advancing Mammoth De-Extinction Efforts

Biotech company Colossal, known for its ambitious project to resurrect the woolly mammoth, has announced a significant achievement in its de-extinction endeavors: the creation of the "Colossal Woolly Mouse." This genetically engineered mouse, born in October 2024, embodies characteristics that could pave the way for the creation of a next-generation woolly mammoth embryo, ultimately intended to be carried by a female elephant.

Colossal’s primary objective is to resurrect a mammoth capable of thriving in the Arctic and contributing to the restoration of the region’s ecosystem. However, directly testing the effects of genetic modifications on elephants presents significant logistical and ethical challenges. Elephants possess a lengthy 22-month gestation period, making experimentation time-consuming. Moreover, it raises ethical concerns to experiment with the elephant population to this degree.

To circumvent these limitations, Colossal turned to the humble laboratory mouse, a scientific mainstay for over a century. Mice share approximately 80% of their genes with humans, rendering them a valuable model for studying genetic processes. Furthermore, their short lifespan (around 2 years) and rapid gestation period (19-21 days) make them ideal subjects for accelerated research.

Colossal scientists meticulously analyzed existing research on mice and cross-referenced specific genes with those found in mammoth DNA. This comprehensive analysis identified seven genes that, when modified in laboratory mice, resulted in significant alterations in coat color, texture, and thickness, mirroring the core characteristics of the woolly mammoth.

"What we found is in 23 days, versus 22 months, it worked," stated Ben Lamm, co-founder and CEO of Colossal. "This is a very, very big step for us because it proves that all of the work we’ve been doing for the last three years on the woolly mammoth is exactly what we predicted."

The genetically engineered mice exhibited notable physical traits, including curled whiskers, wavy, lighter-colored hair that grew up to three times longer than normal, and a rough, woolly texture. Additionally, the mice appeared more full-bodied due to alterations in a gene associated with body weight in mammoths.

An unexpected outcome of the experiment was the perceived cuteness of the modified mice. "They are much cuter than we thought they would be," remarked Lamm. Despite the public’s enthusiasm for the novel creatures, Colossal has no plans to sell or breed them, and the mice are reported to be in excellent health.

The next critical step involves assessing the cold tolerance of the modified mice. If they demonstrate enhanced resilience to cold temperatures compared to standard mice, it would provide strong evidence that the identified genes are indeed crucial for the woolly mammoth’s adaptation to Arctic environments.

Colossal is committed to adhering to the highest ethical standards in its research. The company is consulting with its ethics board and will adhere to the Institutional Animal Care and Use Committee protocols in all future experiments.

Scientists are particularly interested in exploring the potential behavioral differences between the modified mice and their standard counterparts under cold temperatures. They aim to investigate whether the modified mice exhibit increased speed, decreased activity levels, or changes in weight and fat accumulation.

Ben Lamm, a technology and software entrepreneur, and George Church, a renowned biologist at Harvard Medical School, co-founded Colossal Laboratories & Biosciences in 2021 with the express purpose of "rapidly advancing the field of species de-extinction."

The resurrection of mammoths could have profound ecological benefits, potentially revitalizing Arctic grasslands and contributing to climate change mitigation. According to the company, the return of mammoths could promote carbon sequestration, suppress methane emissions, and enhance light reflection.

Colossal scientists have conducted a thorough computational analysis of the ancient genetic makeup of 59 woolly, Columbian, and steppe mammoths, spanning a period from 3,500 to over 1,200,000 years ago. This extensive research has been instrumental in identifying critical genetic targets for creating a next-generation woolly mammoth, which will essentially be a cold-resistant elephant possessing the core biological traits of its extinct ancestor.

"It will walk like a woolly mammoth, look like one, sound like one, but most importantly it will be able to inhabit the same ecosystem previously abandoned by the Mammoth’s extinction," Colossal asserts. The company anticipates the birth of its first woolly mammoth calves by 2028.

In addition to its woolly mammoth project, Colossal is also pursuing the de-extinction of other species. In October 2024, the company announced that it had assembled the most complete Tasmanian tiger genome, marking a significant milestone in its efforts to resurrect the Australian thylacine (Tasmanian tiger). The team hopes to eventually reestablish the Tasmanian tiger on the island of Tasmania off the southeast tip of Australia.

Colossal is also making progress on its project to bring back the dodo, announced in 2023. The company’s Avian Genomics Group is approaching the creation of primordial germ cells in pigeons, which would enable genetic testing of dodo characteristics in pigeons. The dodo-pigeon experiment mirrors the mouse-mammoth approach.

The ability to provide "genetic rescue" to birds could have far-reaching implications, potentially enabling the genetic engineering of bird flu-resistant chickens and other avian species, according to Beth Shapiro.

While Colossal is primarily focused on the "de-extinction" of species, its research breakthroughs could significantly contribute to biodiversity conservation. "We as a society should really be thinking about increasing the tools we have at our disposal to help species survive whatever is going to happen in their habitats," Shapiro emphasized.

Colossal’s progress in de-extinction research, exemplified by the creation of the woolly mouse, represents a monumental step towards revitalizing lost ecosystems and enhancing biodiversity.