Colossal, a passive startup Biosciences has gene-editing mice with mammoth-like characteristics that create what the company calls giant wool mice. Modified to have shaggy fur and a golden coat, Lab Mouse is a demonstration of the kind of gene editing that the company wants to perform on a much larger scale, changing Asian elephants to bring closer to their wool mammoth ancestors.
Giant mouse genomes were longer, frizzy and golden than the usual laboratory mouse genomes, as they were edited at multiple points and replaced fur. Some mice also had compilation of genes involved in fatty acid metabolism. This should change the way animals store fat. This is an important difference between a mammoth and an Asian elephant. Of multiple cohorts of gene-edited mice, one set had edits with seven different genes, most involved in hair types, one that controlled fat metabolism.
Scientists already have a good understanding of how changes in mouse genetics affect fur, so most of the edits chosen by giant scientists have replicated these changes rather than using mammoth DNA as a model. “It wasn’t just about pushing the mammoth gene into the mouse. Beth Shapiro, Chief Science Officer at Colossal, said:
Similar to genes already well understood from mouse studies, giant scientists mined the ancient mammoth genome to identify three genes that appear to be important for mammoth adaptation to cold. Two of these genes affected hair type, while the third gene affected fat metabolism. The researchers then attempted different combinations of editing in different groups of mice, giving birth to curly furry mice, mice with curly whiskers, and fluffy golden coats. This experiment is explained in a preprinted paper that has not yet been peer-reviewed or published in a scientific journal.
“These mice are super adorable,” says Ben Lamm, co-founder and CEO of Colossal. “They’re much cuter than we expected, which means that perhaps our first generation mammoths are just as cute.” Lamb shared photos of wool mice in their habitat in their huge offices and lived in a snowy background accompanied by giant toys of wool. The CEO says the company has no intention of breeding or selling wool mice.
The giant experiment raises questions about which gene editing qualifies to make mice, or what is like an Asian elephant, and Vincent Lynch, a developmental biologist at Buffalo University in New York, was not involved in the giant research. Giant mice are fluffy and frizzier than most lab mice, but while that is true, their properties still appear naturally in other mice. Or, in other words, a chow butterfly like a mammoth than a Chihuahua, is it simply a much fluffy dog?
Where you land on that spectrum is partly a matter of semantics, partly a part of genetics. Colossal calls its derailed mammoth, which has the core biological properties of mammoths, “cold resistant elephants,” but is almost identical to Asian elephants. Lamm said the company has created cold-resistant elephants targeting around 85 genes, and has already experimented with editing 25 genes. He says gene-edited mice can help test invisible properties like fat metabolism, he says.
