How Colossal Biosciences Used Gene-Edited Mice to Validate Its Woolly Mammoth Revival Strategy

Nine targeted gene edits produced a gold, woolly coat and accelerated fat metabolism in all 38 pups, as Colossal expands its mammoth gene target from 65 to 85 genes and aims for a mammoth birth as early as 2028.

All 38 pups expressed the traits. Colossal Biosciences produced 38 woolly mouse pups from nearly 250 embryos across five rounds of experiments, every one of them showing the gold, woolly coat and accelerated fat metabolism of the woolly mammoth through nine targeted gene edits.

Seven of those genes govern the mammoth’s shaggy coat, controlling its coarseness, curl, and length; one gene guides melanin for the gold color, and another governs fat metabolism. Colossal describes the project as validating its end-to-end de-extinction pipeline, with the mammoth gene target expanded from an initial 65 to 85. A mammoth is expected as early as 2028.

This story is based on original reporting by Jeffrey Kluger for TIME. Read the full feature on TIME → https://time.com/7264043/colossal-biosciences-woolly-mouse-bring-back-mammoth/