Philip Johnson to Speak at UMD's Bioscience Day 2019

University of Maryland Biology Assistant Professor Philip Johnson was invited to speak at UMD's Bioscience Day 2019 on November 12, 2019.

His talk will be on "Here a CRISPR, There a CRISPR: Why Not Everywhere a CRISPR?"

Abstract: Just like humans, bacteria and archaea must constantly fend off viral infections. Microbes have developed many anti-viral defense mechanisms, the most fascinating of which is CRISPR-Cas, which serves as a remarkably effective adaptive immune system. While humans have recently hijacked this system for use in precision genome editing, it evolved naturally as a means for microbes to remember past viral pathogens and to defend themselves against future infections by precisely chopping up remembered viral genomes. Despite CRISPR-Cas being found scattered throughout the tree of life (in >40% of sequenced bacteria and archaea) as well as providing near-perfect protection from infection given a matching viral memory, viruses continue to exist and many species of microbes consistently lack a CRISPR-Cas system. I will explore these puzzles and propose hypotheses to explain coexistence and the ecological-evolutionary patterns of CRISPR-Cas incidence.

See the full agenda at