Zebra finch gene system boosts targeted DNA insertion in plants
Caltech researchers report a bird-derived R2 tool inserted plant DNA about 30 times more efficiently than a CRISPR-based method.
By Lucas Ferreira · Science & Environment Writer
3 min read
Caltech researchers have adapted a genetic element from the zebra finch into a tool for placing new DNA at targeted sites in plant genomes. In a paper published June 19 in Nature Biotechnology, the team reported that the system inserted DNA about 30 times more efficiently than a widely used CRISPR-based approach.
The work addresses a long-running problem in plant engineering: adding useful genes without leaving their position in the genome to chance. Caltech said the method could help researchers place several genes at one chosen genomic location, a step that may be useful for designing crops with complex traits.
A tool borrowed from animals
The system is based on an R2 retrotransposon, a mobile genetic element found in many multicellular animals, including insects, crustaceans and birds. According to the study, R2 elements use an encoded protein to copy RNA cargo into DNA at a target site in the genome.
Researchers had previously adapted R2 machinery for gene insertion in mammalian cells, Caltech said, but it was not known whether it could function in plants. The team led by Gözde Demirer, Caltech’s Clare Boothe Luce Assistant Professor of Chemical Engineering, tested R2 editing components from silk moths, white-throated sparrows and zebra finches.
The researchers evaluated the systems in plant leaves, seedlings and protoplasts, which are plant cells stripped of their rigid walls. According to Caltech, the zebra finch-derived R2 system performed best for moving engineered genetic payloads into plant cells.
Why precision matters
For decades, plant scientists have used Agrobacterium tumefaciens, a soil bacterium, to carry new genes into plants. Caltech said that approach can insert DNA efficiently, but the destination is random, which can disrupt existing genes or lead to unpredictable activity.
CRISPR tools gave researchers more control over genome editing after emerging in the early 2010s. The Caltech team said CRISPR-based methods still have difficulty placing large DNA sequences in plant genomes with both accuracy and high efficiency.
The R2 approach is designed to combine precision with efficient insertion, especially for large payloads. According to the paper, that could allow researchers to install several genes at one permissive genome site instead of adding them through repeated rounds of delivery and insertion.
Proof in a tobacco relative
In a proof-of-concept experiment, the researchers used the R2 system to insert a three-enzyme pathway into a leaf of Nicotiana benthamiana, a green plant in the tobacco family. Caltech said the added pathway produced red betalain pigment, showing that the inserted genes were active.
Lead author Kimberley Muchenje, a graduate student in Demirer’s lab, said the delivered genes stayed active during the experiments and showed no sign of silencing. Caltech said that result suggests the targeted site accepted the new genes rather than suppressing their expression.
The researchers described the current results as transient experiments. Caltech said future work will focus on refining the R2 system for crop engineering, including traits that require several coordinated genes.
The study, “Optimized R2 retroelement complexes for DNA insertion into plant genomes,” was authored by Muchenje and colleagues and published in Nature Biotechnology. The DOI listed for the paper is 10.1038/s41587-026-03197-y.
This story draws on original reporting from Phys.org.