The Great Escape: Phage Lysis and Its Control
Ryland Young, Ph.D.
University Distinguished Professor
Texas A&M, Department of Biochemistry & Biophysics
Ryland Young, Ph.D., is the director of the Texas A&M Center for Phage Technology, a University Distinguished Professor, Regents Professor and the Sadie Hatfield Professor of Agriculture in the Texas A&M Department of Biochemistry and Biophysics.
Over his 44-year career at the Texas A&M College of Medicine and College of Agriculture and Life Sciences, Young has made broad advances in the understanding of bacteria-infecting viruses called bacteriophages, or phages. This work was performed in collaboration with many students and colleagues. Overall, Young’s work illuminated the ancient “arms race” between phages and bacteria and shed light on ways to combat antibiotic-resistant bacterial infections.
Young earned his doctorate in molecular biology in 1975 as a National Science Foundation Graduate Fellow at the University of Texas at Dallas. He was a National Institutes of Health, NIH, Postdoctoral Fellow at Harvard Medical School, where he discovered a bacteriophage lambda gene involved in lysis.
In 2003, he was elected as a Fellow of the American Society for Microbiology and a Fellow of the American Academy for the Advancement of Science. He was named the Sadie Hatfield Professor of Agriculture in 2006, a Texas A&M Regents Professor in 2016 and a Texas A&M University Distinguished Professor in 2018.
Lysis is the breakdown of a cell caused by damage to its envelope, which in a bacterial cell, consists of its cytoplasmic membrane and a rigid cell wall. Bacterial lysis was long thought to be a passive process that occurred when the cell couldn’t maintain its envelope structure; indeed, many important antibiotics block extension and maintenance of the cell wall. Viruses that infect bacteria, called bacteriophages (or phages), were also thought to achieve host lysis in the same way. However, Dr. Ry Young, distinguished professor emeritus at Texas A&M University in College Station, discovered that instead, phage lysis is an elaborately regulated and scheduled event that involves a biological clock.
Phages have evolved at least two systems for lysis of the host bacterial cell. One involves multiple genes and proteins, conducted in a precisely timed manner. The second method involves a single protein capable of independently triggering bacterial lysis, and these proteins may provide alternative strategies for developing antibiotic therapies.
Dr. Young has dedicated his career spanning over 4 decades to the study of phages, which continue to surprise and fascinate him with their elegant and highly evolved methods and the hypothesis-driven experimentation they provide. Much of the modern field of phage lysis comes directly from Dr. Young’s research. Even when others turned away from the field, he saw the potential to use phages, with their facile genetics, molecular biology, and biochemistry, to ask specific biological questions. Recently, the scientific community has started looking to phages as a tool for developing antibiotic therapeutics and manipulating human microbiota.
1. To understand the molecular mechanisms of Multigene Lysis, by which dsDNA phages cause the lysis of the host cell in a precisely timed manner.
2. To understand the contrasting single-gene strategies (SGL) used by the much smaller ssDNA and ssRNA phage for host lysis.
3. To pose the question why are Sgl mechanisms restricted to small phages.
This page was last updated on Thursday, November 2, 2023