Ignazio Carbone was born in Toronto, Canada. He received his B.S. degree in toxicology and pharmacology in 1992 and his M.S. and Ph.D. degrees in evolutionary biology in 1994 and 2000, respectively, from the University of Toronto. In 2002, he joined the Department of Plant Pathology at North Carolina State University, where he is now an associate professor. Carbone is internationally recognized for his advances in our understanding of how evolutionary forces contribute to population structure, developing novel and user-friendly analytical methods and tools for contemporary population analysis and translating this knowledge to application. He is an authority and pioneer in applying coalescent-based analytical methodologies to gain insight into the complex underlying evolutionary processes that have shaped contemporary populations of bacteria, fungi, and viruses. These analytical tools and methods have broad application beyond the plant pathology and mycology communities. For example, they are currently used to test hypotheses related to the emergence of modern humans from different continents based on genealogical analysis of the human Y chromosome and to better understand the evolutionary processes that drive diversification in fungal endophytes.
Carbone’s major contributions have come from his seminal research on the evolution of aflatoxin biosynthesis by species of Aspergillus. His research focuses on the central question of whether secondary metabolites evolved prior to, along with, or subsequent to events involved in speciation. To address this question, he has combined inferences from macro- and micro-evolutionary analyses to understand the conservation of fungal bioreactive compounds among species of Aspergillus and how genetic diversity is generated and maintained within species on a spatial and temporal scale. These inferences are based on a combined analysis of global populations, genomic arrangement of the aflatoxin gene cluster, and heritability of aflatoxin biosynthesis.
Carbone’s extensive population analysis was key to the discovery of the Petromyces sexual stage of Aspergillus flavus. By choosing populations of A. flavus with 1:1 ratios of both mating types, Carbone and his colleague Bruce Horn were able to produce the sexual stage in the laboratory. The demonstration of sexual recombination within this species allowed Carbone to challenge and disprove the currently accepted dogma that recombination occurs only within populations of A. flavus via parasexual recombination and between strains within the same vegetative compatibility group (VCG).
The ability to perform sexual crosses in the laboratory demonstrated that the transfer of genes is not restricted by VCG group. Results from the mating experiments also identified hot spots for recombination within the aflatoxin biosynthetic cluster and provided evidence that nontoxigenic strains can acquire the ability to produce aflatoxin. These laboratory data are consistent with population analyses showing that populations with evidence of recent recombination contain a greater percentage of aflatoxin-producing isolates than clonal populations.
Carbone’s research findings have broad implications for developing more effective approaches for deploying biological control agents in Africa and other parts of the world. First, the population genetics data of A. flavus provides critical a priori knowledge for developing and selecting more effective biological control strains. Carbone showed that the introduction of closely related nontoxigenic genotypes into native soil populations of A. flavus is more effective than introduced unrelated genotypes. Second, information on recombination within A. flavus supports a management strategy based on the application of female sterile (male fertile) strains that will drive the recombining population to a clonal one that produces less aflatoxin. Without the integration of information on the population genetics, biogeography, and reproductive biology, reliable models to predict and manage populations of A. flavus would not have been possible.
Carbone also has made significant advancements in developing tools that enable biologists to take advantage of complex evolutionary methods. One of these toolkits, called SNAP, is widely used and represents a significant advance in software for the analysis of populations. The SNAP toolkit is a powerful tool for addressing questions related to species boundaries, phylogeography, and origin and spread of organisms. The wide adaptation of these tools is demonstrated by his publications across a spectrum of high-impact journals that target both general biologists and specialist in the field of pathogenic and nonpathogenic organisms.
Recently, Carbone has integrated population genetics, metagenomic, and genome assembly tools into a comprehensive package that is freely available to the public through a web-based portal at North Carolina State University. This suite of tools, designated as Mobyle SNAP Workbench, provides powerful analytical methods that are accessible to researchers with varying levels of expertise. Carbone has presented several workshops on his bioinformatics tools at APS annual meetings. The popularity of the workshops is further engendered by Carbone’s engaging and passionate style of teaching.
Carbone has multiple publications in high-impact disciplinary journals, including Nature and Proceedings of the National Academy of Sciences. Further, multiple citations of Carbone’s research reflect the use of his conceptual insight and tools by both fundamental scientists investigating evolutionary patterns of genes and gene clusters as well as applied scientists studying disease ecology and pathogen variation. In recognition of the impact of his research, Carbone has received awards from professional societies. In 2008, Carbone was awarded the C. J. Alexopoulos Prize, awarded annually by the Mycological Society of America to an outstanding early-career mycologist. In 2009, he received the Syngenta Award, given by Syngenta Crop Protection to an APS member for his research contributions.
In addition to his research program, Carbone is also the director of the Center for Integrated Fungal Research at North Carolina State University. This center, composed of 14 scientists across two academic colleges, focuses on modeling, predicting, and managing the consequences of environmental impacts on microbes and microbial processes from the subcellular to large-scale ecosystems.
Ignazio Carbone’s seminal contributions to the scientific community have secured his leadership role at the forefront of microbial evolutionary biology. He has provided a conceptual framework for understanding the evolution of populations, and he has made a major contribution toward the control of a disease that has a global impact on human health.
