Nearly 40 years ago, a young graduate student climbed the steps of Agronomy Hall at the University of Minnesota, eager to begin the next chapter of his academic journey. Today, that same scholar—Dr. Rick Jellen, now a professor in BYU’s Department of Plant and Wildlife Sciences—celebrates the publication of his research on oat genomics in the prestigious scientific journal Nature.
The path to this achievement began five years ago at an international genomics conference in San Diego, where a conversation between colleagues sparked an ambitious global effort to sequence not one oat genome, but thirty. “Oat is the sixth or seventh most important cereal food worldwide,” says Jellen, citing its cholesterol-lowering fibers and antioxidant compounds. Though a staple in Northern Europe, primarily as livestock feed, oats present agricultural challenges. “Three wild oat species are among the most economically damaging weeds,” he notes.
Adding to their complexity, oats have a highly dynamic genome—three to four times larger than the human genome—with far more chromosomal rearrangements than other cereal crops. These structural variants complicate selective breeding and can cause partial sterility when chromosomes fail to pair correctly. “Crossing two parents that differ for any one of these rearrangements will reduce the breeder’s ability to combine genes for traits encoded within the differing SV segments,” Jellen explains. He believes future breeding efforts will account for these genomic rearrangements when selecting parent plants.
To address these challenges, Jellen and BYU Plant and Wildlife Sciences Professor Jeff Maughan joined researchers from Australia, Canada, Germany, and the UK to build a pan-genome—a comprehensive map of all genes found across oat varieties. “Everyone brought something unique to the table,” Maughan shares. “That collective effort led to discoveries that just wouldn’t have been possible if we’d been working in isolation. It really showed the power of global collaboration in science.”
Their goal was to capture both core genes shared among oats and variable genes that distinguish them. To ensure accurate comparisons, all plants were grown under identical conditions, with samples collected from the same tissue at the same stage of growth. Using both DNA and RNA sequencing, the team identified genetic traits and pinpointed genes that may influence other key traits.
Among their findings was the confirmation of two distinct gene pools: Northern European and Mediterranean. Structural differences between them make crossbreeding difficult, yet breeders have been mixing these varieties for almost a century. “What oat breeders around the world have been doing is introducing novel barriers restricting gene exchange at the chromosome level,” Jellen shares.
The pan-genome provides a crucial genomic baseline to help breeders avoid inheriting unfavorable traits. “Having this kind of detailed genetic roadmap helps us figure out what the genes are doing and, ultimately, how to breed new oat varieties with enhanced health benefits,” Maughan remarks. It also links specific chromosomal changes to climate adaptation, offering insight into how oats thrive in diverse environments and how genetic isolation can lead to new species. “Plant breeders depend on genome-wide chromosome pairing and gene exchange when they cross two parents to produce a higher-yielding new cultivar,” says Jellen. “With the knowledge and tools in this manuscript, oat breeders can now more intentionally select parents to maximize the likelihood of gene exchange in the breeding process.”
The significance of these discoveries didn’t go unnoticed. According to Jellen, three key factors helped this research to catch the attention of Nature. “Oats are a highly nutritious source,” he explains. “I think their economic significance combined with the comprehensive nature of our study and the intriguing evolutionary insights into structural variance are what attracted Nature.”
Beyond its scientific contributions, this publication marks a deeply personal milestone for Jellen. He has been writing about structural rearrangements since his PhD days, often with little recognition. Yet he remained committed to highlighting their importance, believing them to be key to understanding environmental adaptation. Now, after decades of persistence, his work has earned a place in one of the world’s most prestigious scientific journals. “This paper is a vindication of almost 40 years of research,” Jellen shares. “It’s a big honor.”
Read Jellen and Maughan’s Nature article here.