For scientist Simon Sretenovic, seeing was the first step to believing.
As a child in Slovenia, Sretenovic remembers his elementary school class putting the water of a pond under the microscope to reveal the world hidden inside. He was deeply impressed with microscopy and how it could reveal things hidden in plain sight.
Now, as a doctoral student, he is pursuing research that he believes can help realize the future of agricultural biotechnology while simultaneously satisfying his own insatiable curiosity for biology.
Sretenovic’s childhood inspiration took him to high school where he continued to tinker with the microscope. Only this time he was looking at GFP – Green Fluorescent Protein – a natural protein extracted from jellyfish that glows green in the right light. This protein, a tool commonly used in many cellular and molecular biology studies, accelerated Sretenovic on the path to microscopy.
Sretenovic, a Rockey FFAR Fellow, then graduated in electron microscope where he studied the development of biofilms in microbes for his master’s degree. This work reaffirms his desire for what he describes as “organoleptic perception”.
“When you get a really good representative shot, it’s a great find,” he said. “Seeing is believing.”
This research also scratched his itch to know how the world around him worked. Growing up, he and his father, an electrical engineer, played Legos and built circuits together. He loved the feeling of knowing how the building blocks of the world came together and the mechanisms that drove their function.
As a speaker in Slovenia, Sretenovic continued to explore the realm of possibilities before him. It found its calling when CRISPR came on the scene in a big way in 2012.
“I thought it was good technology with huge potential for impact,” he recalls.
Putting aside his earlier need for visual affirmation, Sretenovic took a huge leap of faith and immigrated to the United States to begin his doctorate. in Plant Molecular Genetics at the University of Maryland, College Park, Dr. Yiping Qi’s laboratory.
Here he explores his interests in CRISPR-mediated genome editing in plants. Classic CRISPR applications use Cas9 to induce double-strand breaks in DNA. However, Sretenovic wants to extend this set of tools to modify plant genomes in new ways.
He describes the opportunities for future tools as being able to “improve target range limiting, increase editing efficiency, so you have to filter out fewer plants and increase specificity.”
One of the tools his work is centered around is basic editors. Core editor applications use the classic CRISPR/Cas system to focus on a highly targeted region of the genome. However, instead of introducing mutations through double-strand breaks, base editing allows the conversion of one nucleotide to another. More often than not, basic editors make the transitions from C to T easier.
Sretenovic believes that good scientific tools are crucial for social progress.
“Plants that could be produced with these tools would be easier [than GMOs] to be developed commercially,” he noted, describing features such as elongated grain length in rice as potential targets achievable by basic editing.
Sretenovic believes the future of food will include genetically modified crops.
“At first it was traditional breeding, then mutagenesis breeding, then RNA interference and now it’s CRISPR technology,” he explained. “It’s a natural progression.”
Image: Simon Sretenovic examines rice plants in a research greenhouse. Photo: Dr Changtian Pan