Adaptation of CRISPR repertoires to the virome

Recent theoretical work suggests that the structure and organization of the immune repertoires of prokaryotes are shaped by adaptation to the statistics of viral infections. We explain these findings and their implications for the principles underlying CRISPR-based adaptive immunity. We discuss how more comprehensive sampling of natural viral diversity both across ecosystems, and across time, will inform these theories and our understanding of immunity against phage. Underlying this perspective is an analogy to the theory of sensory systems in neuroscience where adaptation to the statistics of the natural world has provided a powerful explanatory paradigm.