Joyce Bergelson, PhD and Olaf Schneewind, MD, PhD – Elected to National Academy of Sciences
The National Academy of Sciences is charged with providing independent, objective advice to the nation on matters related to science and technology, and membership is one of the highest professional honors a scientist can achieve. Selected by their peers, these two are now part of an exclusive group recognized for their distinguished and continuing contributions to research.
Research in Bergelson’s lab is best known for dispelling the long-held belief that arms-race dynamics typify the evolution of plant resistance to microbial pathogens in nature. An early researcher on the plant Arabidopsis thaliana, particularly from an evolutionary and ecological perspective, Bergelson and her group completed the first experiments using genetically manipulated plants to disentangle the mechanisms driving observed evolutionary dynamics. They also have pioneered research at the interface of ecology and evolution, namely eco-evolutionary dynamics. Through her international collaborations, Bergelson has been instrumental in developing genome-wide association mapping in Arabidopsis, providing resources to the community and ultimately leading to the 1001 Genomes project.
Schneewind is best known for his work discovering sortases — enzymes that assemble proteins in the envelope of Gram-positive bacteria. Sortases cleave sorting signals at motif sequences for subsequent attachment (covalent linkage) to cell wall peptidoglycan or for polymerization into pilus structures, which enable them to adhere to other bacterial or to animal cells. Without sortases and their surface protein substrates, bacteria (such as Staphylococcus aureus or its drug-resistant forms, known as MRSA) cannot cause disease or interact with their environment. Investigation of sortase motif sequences has enabled Schneewind and his team to identify the surface proteins of any bacterial pathogen based on genome sequences and to study these molecules for their contributions to disease establishment and for vaccine development. These insights have allowed his team to find and study how S. aureus evades detection by the immune system and to create vaccines for safety and efficacy testing in humans.