Meet The Microbiologist - The Scientists Behind The Microbiology

CRISPR is a genome-editing tool, but what is its role in microbial biology and evolution? Joe Bondy-Denomy discusses his discovery of the first anti-CRISPR protein and the many unanswered questions surrounding CRISPR biology. Julie’s Biggest Takeaways CRISPR is a bacterial immune system that identifies and destroys specific nucleotide sequences. These sequences are most commonly associated with foreign DNA from bacteriophage or plasmids. Bacterial acquisition of new CRISPR spacer sequences is fairly inefficient, and often a bacterium dies before acquiring and fending off a new phage infection. Only about 1 in a million cells emerge from a phage infection with a new spacer sequence, likely driven defective phages that act as a vaccine of sorts to provide spacer sequence material. 40% of bacteria and 85-90% of archaea have had some sort of CRISPR system detected in their genomic sequences. Most bacteria have Type I CRISPR system. This system includes different proteins that serve unique functions: one holds ont