Graduate student Chuan Li received the 2015 Society for Molecular Biology and Evolution Graduate Student Poster Award for her groundbreaking research related to multidrug resistance of pathogens and how certain mutations cause disease. Li’s poster was titled "The fitness landscape of a yeast tRNA gene" and the award included $250. Only five awards were given out of some 500 posters at the SMBE annual conference in Vienna held in July 2015. Li’s advisor is Professor Jianzhi Zhang.

“Mutation provides the raw material for all genetic variation and evolution,” explained Li. “The distribution of the fitness effects of all mutations, known as the fitness landscape, is of fundamental importance for understanding almost all evolutionary processes. This project will generate the first large-scale fitness landscape of a gene in any cellular organism. The data will offer unprecedented details of the fitness effects of mutations, including properties of genetic interaction among mutations (i.e., epistasis) and provide an invaluable opportunity to test many theoretical models that depend on assumptions about the fitness landscape and epistasis.

“These theoretical models apply to many important phenomena such as the origins of multidrug resistance in pathogens and the domestication of animals and plants. The gene to be studied is a budding yeast tRNA gene. The rich information about the tRNA structure will allow a molecular-level mechanistic interpretation of the fitness landscape, helping understand why certain tRNA mutations cause disease. The methodology developed here can be used to study other genes or in other organisms.”