Spiegazione semplice
Francisco Mojica noticed that the unique sequences sitting between CRISPR's repeating blocks matched viral DNA. That meant microbes were keeping a genetic record of infections they had survived. Everything else follows from that observation.
Approfondisci
Mojica, Díez-Villaseñor, García-Martínez and Soria reported that spacer sequences within CRISPR arrays match bacteriophage and plasmid sequences, proposing an adaptive immune function. The paper was rejected by several journals before publication — a frequently cited example of how difficult genuinely novel results can be to publish.
Sources
- Journal of Molecular Evolution · 2005
Intervening sequences of regularly spaced prokaryotic repeats derive from foreign genetic elements ↗