Telling the Story of Science: Holly Elmore

During January 2014, the GSAS workshop ComSciCon Local helped young researchers learn how to communicate complex and technical ideas in a way that makes them vivid and comprehensible to a broad audience. Organized by Communicating Science, an organization founded and run by PhD students from Harvard and MIT, the workshop culminated with students preparing brief articles that answered the question, “What surprising role will your field take in explaining, shaping, or solving a problem faced by society this century?” Below is one student’s response. This is part one of a four part series.

The Story Behind the Story of Life

Image

In my comparative genomics research, studying the genomes of fungi makes me feel like a detective getting to know a neighborhood. Sometimes the equivalent of graffiti on the walls or garbage in the streets can tell amazing stories—tales of trauma, death, desperate measures, and change that is occurring much faster than any of us once suspected. Take the fungal agricultural pathogen Fusarium oxysporum. I identified a possible defensive adaptation to a common pesticide without ever having studied the organism itself, just by following the leads in its genome.

The characters in this story, the genes, can belong to a “family” of similar genes, a group of “colleagues” in the same metabolic pathway, and a “neighborhood” in the same physical location on the chromosome. Every strain of this fungus has the two genes that together combat this pesticide, but in some strains, the two are next-door chromosomal neighbors as well as colleagues. This physical proximity allows the genes to better work together, particularly when they are both needed on short notice to counteract a toxin. On top of that, this pair is ready to relocate together to new strains of the fungus on a mobile chromosome. Most chromosomes, like most neighborhoods, stay put. Mobile chromosomes, however, do not confine themselves to one lineage of parents and offspring, but can cross the borders between genetically distant individuals like a caravan, spreading the potential pesticide resistance to new strains. Their gain is our agricultural loss.

So, how did I piece all this together? Good, old-fashioned detective work aided by some fancy computational tools. Genomes are often described as a set of instructions to build and maintain an organism, but that is not the whole story. The working genes (the neighbors) represent only a sliver of the genome; the rest is a mixture of crucial genomic context (roads and buildings) and genetic garbage (trash and graffiti), that together form a historical record. I compare different genomes, all of which are variations on a common ancestor’s theme, to better understand how evolution takes its many paths.

Curiosity drove me to investigate this case, but the results led me to some very practical conclusions. Before the genomic era, we did not appreciate how many avenues are available for resistance to evolve. The genes themselves are no different between strains, but their context—next-door neighbors on a mobile chromosome—can lead them to work together in very different ways, leading to differences in each strain’s pesticide sensitivity.

Beyond even the practical lessons, there is something profound about exploring an organism’s genetic environs. F. oxysporum’s genome bears the traces of the chaotic history behind an evolutionary arms race—a gripping and almost relatable account, for those who know how to interpret it. This kind of work was inconceivable just half a century ago, before we could read the genetic code. Through comparative genomics, I have the privilege of exploring a world that is both completely foreign and strangely familiar, following clues to solve mysteries that could lead to a better future and deeper understanding of the story behind the story of life.

Holly Elmore is a first-year PhD candidate in organismic and evolutionary biology. She did this work with colleagues from Vanderbilt University.
 

Photo by Ben Gebo