Ewen Callaway in Nature:
“Where’s my tail?”
Geneticist Bo Xia asked that question as a child and it was on his mind again a few years ago, while he was recovering from a tailbone injury during his PhD at New York University (NYU) in New York City. Xia and his colleagues now have an answer. The researchers identified a genetic change shared by humans and other apes that might have contributed to their ancestors’ tail loss, some 25 million years ago. Mice carrying similar alterations to their genomes had short or absent tails, the researchers found — but that insight was hard won. The work was published on 28 February1: nearly 900 days after being submitted to Nature and posted as a preprint, because of extra work needed to develop several strains of gene-edited mice and demonstrate that the genetic changes had the predicted effect.
“Respect to the authors,” says Malte Spielmann, a human geneticist at Kiel University in Germany, who reviewed the paper for Nature. “I’m incredibly excited about the fact that they’ve really pulled it off.”
The mice with no tails
Unlike most monkeys, apes — including humans — and their close extinct relatives don’t have tails. Their coccyx, or tailbone, is a vestige of the vertebrae that constitute a tail in other animals. Finding the genetic basis for this trait wasn’t what Xia, now at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts, planned to devote his PhD to. But his coccyx injury, sustained during a cab ride, reinvigorated his tail curiosity.
More here.