Summarize this content to 2000 words in 6 paragraphs Scientists looking to bring the extinct woolly mammoth back to life have made adorable progress—using gene editing to create a “woolly mouse.”The team at genetics and biotech firm Colossal Biosciences have imbued rodents with thicker, woolly coats, golden fur and other cold-climate adaptations, all of which are key characteristics of the iconic woolly mammoth.”The Colossal Woolly Mouse marks a watershed moment in our de-extinction mission,” said Colossal Biosciences co-founder and CEO Ben Lamm.”This success brings us a step closer to our goal of bringing back the woolly mammoth.”
The Colossal Biosciences woolly mouse
The Colossal Biosciences woolly mouse
Colossal Biosciences
In their latest work, Colossal researchers analyzed the genomes of 62 elephants and 59 mammoths—dating back between 1,200,000 and 3,500 years ago—picking out those genes that have a significant impact on hair and other traits that help adapt to cold environments.In particular, the team focused their attention on a suite of genes in which woolly mammoths exhibit fixed differences when compared with Asian elephants, their close cousins.They then narrowed down their list to 10 genes that play a role in hair properties (including color, length, texture and thickness) and lipid metabolism—and are compatible with mice.Finally, the researchers used a mixture of gene editing techniques to modify seven of these genes in the genome of a lab specimen—creating a “woolly mouse.”The gene edits made in the woolly mouse give it an altered hair growth cycle—meaning its coat can grow three times longer than wild type mice.Changes to other genes related to the development and structure of hair follicles also gave it a woolly hair texture, wavy coat and curled whiskers.The woolly mouse also has a light-colored coat, as seen in mummified woolly mammoth specimens, thanks to an alteration to a gene that regulates the production of the pigment melanin.Alongside helping to pave the way toward the potential return of the woolly mammoth, the researchers say that the woolly mouse will provide both a living model for studying cold-climate adaptations in mammals and an example of how multiple genes work together to produce given physical traits.
An artist’s impression of a woolly mammoth.
An artist’s impression of a woolly mammoth.
Orla/iStock / Getty Images Plus
“I’m incredibly proud of what our team has accomplished here in the lab in such a short period of time,” said molecular microbiologist Michael Abrams, who co-leads Colossal’s Mammoth Team.”We’ve pushed the boundaries of genetic engineering by coordinating multiple complex trait modifications in living animals with exceptionally high efficiency.”This achievement showcases both the technical expertise of our scientists and the power of our genetic engineering platform to deliver predictable phenotypes.”Lamm added: “By engineering multiple cold-tolerant traits from mammoth evolutionary pathways into a living model species, we’ve proven our ability to recreate complex genetic combinations that took nature millions of years to create.”
Other experts, however, have poured cold water on the development.”Colossal’s team made a number of genetic changes known as ‘knock outs’ in lab mice that are already known to produce longer, thicker, wavier—or woollier—coats in mice. They also made a change known to cause blonde hair coloring in mice,” said Tori Herridge, an evolutionary biologist at the University of Sheffield in England who was not involved in the present study.”The result, therefore, of various ‘woolly mice’ from these genetic changes is unsurprising; woolly mice have been produced in labs and by mice breeders many times before.”She added: “A mammoth is much more than just an elephant in a fur coat. While we know a lot about mouse genetics, we know much less about mammoths and elephants. It isn’t yet known which sections of the genome are vital for achieving the characters needed to make an elephant fit for life in the Arctic Circle. Genes that are linked to fur and fat in well-studied animals like mice are obvious targets, but the devil is in the detail.”Evolutionary biologist Saad Arif of Oxford Brookes University, England—who was also not involved in the present research—agreed, adding: “I think we are still very far from their ‘de-extinction’ goal. The elephant and mammoth genomes are considered to be 96.4 percent identical, however, that still leaves potentially another ~13 million changes in DNA sequence to consider.”It is also still unclear how mammoth cold-adaptation phenotypes without a clear outward manifestation could be identified or screened in mice.”However, Arif noted, the techniques employed to create the woolly mouse are useful. “One novel element of the work seems to be the use of genome-editing technologies to alter multiple genes at once with high efficiency and speed in mice,” he said. “Although we have had the ability to alter multiple genes at once for sometime, the efficiency and speed with which these changes can be made could still be improved.”Based on the results presented by the authors, their methods for generating transgenic mice with the desired changes appears to be both rapid and highly efficient, which would be extremely desirable when testing for the function of genetic changes in any context, whether it has implications for conservation or disease biology.”Do you have a tip on a science story that Newsweek should be covering? Do you have a question about de-extinction? Let us know via science@newsweek.com.
