Brian Lazzaro

Liberty Hyde Bailey Professor


I am interested in the evolutionary genetics of insect-pathogen interactions. I am especially interested in identifying genetic and environmental factors that contribute to infection outcomes, focusing on both host and microbe factors that shape the kinetics of infection. In broader context, I would like to understand how genetics and environment contribute to disease transmission and control, including through life history constraints that limit infectivity and immunity. I have been a professor at Cornell since 2003.

I teach a variety of courses at Cornell, including BioEE 4800 Ecological Genetics and BioEE 1780 Evolution and Diversity, and I am the Director of the Cornell Institute for Host-Microbe Interactions and Disease (CIHMID).

Research Focus

My research is focused on the evolutionary genomics of insect-pathogen interactions, emphasizing such questions as how natural selection operates on host immune systems and why individuals vary in susceptibility or resistance to infection. In my group, we like to think of the host as an assemblage of interacting physiological processes, where the immune system is embedded in the overall physiological context of the host. This motivates us to consider effects of abiotic environment on immune defense and means that genetic determination of variation in resistance may lie in genes outside of the canonical immune system. This thinking also extends directly to the evolution and mechanism of life history constraints. Importantly, the host is itself the “environment” in which an infecting pathogen lives, and differences in host physiological state or abiotic environment can alter microbial behavior and therefore ultimate outcomes of infection. Our overarching goal is to consider host and pathogen as interacting components of a single system, shaped by the environment, that ultimately determines the outcome of infection and disease. We primarily use bacterial infection in Drosophila melanogaster as an experimental model to deconstruct elements of the unified system, studying the components in tractable modular pieces. Understanding the dynamics of unified host-pathogen-environment systems is crucial, because these dynamics determine the ecology and evolution of disease in natural settings with consequence at higher biological scales.


Please see a list of publications here.