Recommended by: Joseph Ecker, Salk Institute
Robert Schmitz developed his interest in epigenetics and plant science while an undergraduate at the University of Arizona. There, he was influenced by the work of two prominent plant scientists: Vicki Chandler, who was studying the epigenetic phenomenon known as paramutation in maize, and Richard Jorgensen, who helped define the occurrence of post-transcriptional gene silencing and small RNAs while working with petunias.
Schmitz, who is now a member of the Ecker lab at the Salk Institute for Biological Studies, recently won an NIH grant to study variation and heritability of epigenetic information in Arabidopsis thaliana.
Schmitz is using a combination of genome sequencing of different A. thaliana strains and whole-genome bisulfite sequencing to better understand variation in DNA methylation — work that has implications for both plant and human biology.
"One thing you can envision is that you not only have genetic variants that can give rise to diseases, but there is this really nice interplay that occurs in evolution between genotype and epigenotype," Schmitz says. "We know there are certain genetic variants that can influence methylation states in nearby genes. This is something we can pick apart using Arabidopsis."
Paper of note
This work has already led to Schmitz co-authoring a paper that was published last fall in Science and that Salk's Ecker calls "pioneering." In that study, Schmitz and colleagues examined the amount of spontaneous epigenetic variation that can occur over generations in the absence of significant genetic variation. "We showed that these single methylation polymorphisms, we call them SMPs, occur at greater rates than SNPs," he says.
The next step, Schmitz says, is to study population-wide epigenomics in Arabidopsis. He says that early work, currently under review for publication, has shown that there is "extensive natural epigenetic variation," about a third of which is associated with underlying genetic variants.
"What those genetic variants are that give rise to these methylation variants is unclear at this point — and that's future work — but where do the other 70 percent of these methylation variants come from? Right now it's just a big mystery," he says.
Schmitz says that he would like to see the field of epigenomic variation "take more of a biotechnology turn" such that researchers can begin controlling epigenetic alleles.
And the Nobel goes to…
Schmitz subscribes to the theory that great discoveries, like those leading to Nobel Prizes, are, for the most part, serendipitous. "I like to think that … by keeping our heads down and working hard … those great discoveries come from doing great science," he says. "And you just can't predict what they'll be."