Order of authorship in the original publication: Al-Shayeb, Sachdeva, Chen.... Doudna.  Open access, available from nature.com at this link.

This paper was a collaboration of about 50 scientists of diverse regions and specialities, assembled to advance knowledge of the bacteriophage evolutionary response and the tools huge phages possess against the onslaught of the bacterial immune system. The authors reconstructed 351 phage sequences and derived metagenomics datasets acquired from human feces, buccal areas, animal fecal samples, freshwater lakes and rivers, marine ecosystems sediments, hot springs soils, deep subsurface habitats, etc., mirroring most aspects of the earth's ecosystems. The main findings of this research were:

1. Many of the genomes of large phages have a length that rivals those of small celled bacteria.

2. These expanded genomes of large phages include diverse and previously undescribed CRISPR-Cas systems, TRNA's, tRNA synthases, tRNA modification enzymes, ribosomal proteins and others.

3. CRISPR-Cas systems of phages have the capacity to silence host transcriptional factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage encoded functions.

4. Some phages may repurpose bacterial CRISPR-Cas systems to eliminate competing phages.

5. The number of huge genome phages was far higher than expected.

6. Some phages that lack genes for interference and spacer integration have similar CRISPR repeats as their hosts and may therefore use the Cas proteins of the host.

(Thanks to Juan Weiss for this reference and its interpretation.)