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Brian Lazzaro

Liberty Hyde Bailey Professor

photo of Brian Lazzaro

Comstock Hall-Academic II, Room 3134

Educational Background

Ph.D., Pennsylvania State University (2002)

B.S., University of California, Davis (1995)



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).


Antibacterial defense, bacteria, disease, Drosophila, evolution, health, insect immunity, malaria, microbiota, mosquito, population genetics, quantitative genetics 


  • Ecology and Evolutionary Biology

Graduate Fields

  • Comparative Biomedical Sciences
  • Ecology and Evolutionary Biology
  • Entomology
  • Genetics, Genomics and Development


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. More detail can be found on our lab’s research website at



  • Unckless, R.L. and B.P. Lazzaro. The potential for adaptive maintenance of diversity in insect antimicrobial peptides. Philosophical Transactions of the Royal Society, Biology, 371:20150291.
  • Crawford, J.E., M.M. Riehle, K. Markianos, E. Bischoff, W.M. Guelbeogo, A. Gneme, N. Sagnon, K.D. Vernick, R. Nielsen, and B.P. Lazzaro. (2016) Evolution of GOUNDRY, a cryptic subgroup of Anopheles gambiae s.l., and its impact on susceptibility to Plasmodium infection. Molecular Ecology 25:1494-1510.
  • Unckless, R.L.*, V.M. Howick*, and B.P. Lazzaro. (2016) Convergent balancing selection on an antimicrobial peptide in Drosophila. Current Biology 26:257-262 *denotes co-first authorship
  • Schwenke, R.A., B.P. Lazzaro, and M.F. Wolfner. (2016) The basis for immunity-reproduction tradeoffs in insects. Annual Review of Entomology 61:239-256.
  • Crawford, J.E., M.M. Riehle, W.M. Guelbeogo, A. Gneme, N. Sagnon, K.D. Vernick, R. Nielsen, and B.P. Lazzaro. (2015) Reticulate speciation and barriers to introgression in the Anopheles gambiae species complex. Genome Biology and Evolution 7:3116-3131.
  • Webster, C.L., F.M. Waldron, S. Robertson, D. Crowson, G. Ferrari, J.F. Quintana, J.M. Brouqui, E.H. Bayne, B. Longdon, A.H. Buck, B.P. Lazzaro, J. Akorli, P.R. Haddrill and D.J. Obbard. (2015) The discovery, distribution, and evolution of viruses associated with Drosophila melanogaster. PLoS Biology 13(7):e1002210.
  • Lazzaro, B.P. (2015) Adenosine signaling and the energetic costs of induced immunity. PLoS Biology 13(4): e1002136.
  • Commentary on Bajgar et al. 2015
  • Unckless, R.L., S.M. Rottschaefer and B.P. Lazzaro. (2015) The complex contributions of genetics and nutrition to immunity in Drosophila melanogaster. PLoS Genetics 11(3): e1005030.
  • Unckless, R.L., S.M. Rottschaefer and B.P. Lazzaro. (2015) A genome-wide association study for nutritional indices in Drosophila. G3: Genes, Genomes, Genetics 5(3):417-425.
  • Dobson, A.J., J.M Chaston, P.D. Newell, S.L. Ali, L. Donahue, D.R. Sannino, S. Westmiller, A. C.-N. Wong, A.G. Clark, B.P. Lazzaro and A.E. Douglas. (2015) Host genetic determinants of microbiota-dependent nutrition revealed by genome-wide analysis in Drosophila melanogaster. Nature Communications 6:6312.
  • Rottschaefer, S.M, J.E. Crawford, M.M. Riehle, W.M. Guelbeogo, A. Gneme, N. Sagnon, K.D. Vernick and B.P. Lazzaro. (2015) Population genetics of Anopheles coluzzii immune pathways and genes. G3: Genes, Genomes, Genetics 5(3):329-339.
  • Khalil, S., E. Jacobson, M.C. Chambers and B.P. Lazzaro. (2015) Systemic bacterial infection and immune defense phenotypes in Drosophila melanogaster. Journal of Visualized Experiments 99:e52613.
  • Chambers, M.C., E. Jacobson, S. Khalil and B.P. Lazzaro (2014) Thorax injury lowers resistance to infection in Drosophila melanogaster. Infection and Immunity 82:4380-4389.
  • Lazzaro, B.P. and D.S. Schneider (2014) The Genetics of Immunity Genetics 197:467-470; G3: Genes, Genomes, Genetics 4:943-945.
  • Howick, V.M. and B.P. Lazzaro (2014) Genotype and diet shape resistance and tolerance across distinct phases of bacterial infection BMC Evolutioary Biology 14:56.
  • Short, S.M. and B.P. Lazzaro (2013) Reproductive status alters transcriptomic response to infection in female Drosophila melanogaster G3: Genes, Genomes, Genetics 3:827-840.
  • del Campo, M.L, R. Halitschke, S.M. Short, B.P. Lazzaro and A. Kessler. (2013) Dietary plant phenolic mediates tolerance to bacterial infection in Manduca sexta caterpillars. Entomologia Experimentalis et Applicata 146:321-331.
  • Crawford, J.E., S.M. Rottschaefer, B. Coulibaly, M. Sacko, O. Niaré, M.M. Riehle, S.F. Traore, K.D. Vernick and B.P. Lazzaro (2013) No evidence for positive selection at two potential targets for malaria transmission-blocking vaccines in Anopheles gambiae s.s. Infection, Genetics, and Evolution 16:97-92.