Five Big Mysteries about CRISPR’s Origins
Where did it come from? How do organisms use it without self-destructing? And what else can it do?
Francisco Mojica was not the first to see CRISPR, but he was probably the first to be smitten by it. He remembers the day in 1992 when he got his first glimpse of the microbial immune system that would launch a biotechnology revolution. He was reviewing genome-sequence data from the salt-loving microbe Haloferax mediterranei and noticed 14 unusual DNA sequences, each 30 bases long. They read roughly the same backwards and forwards, and they repeated every 35 bases or so. Soon, he saw more of them. Mojica was entranced, and made the repeats a focus of his research at the University of Alicante in Spain.
It wasn't a popular decision. His lab went years without funding. At meetings, Mojica would grab the biggest bigwigs he could find and ask what they thought of the strange little repeats. “Don't care about repeats so much,” he says that they would warn him. “There are many repeats in many organisms — we've known about them for years and still don't know how many of them work.”