Cornell researchers have discovered how transposons, or ‘jumping genes,’ insert themselves into bacterial chromosome ends, potentially transforming genetic engineering and advancing biotechnology. This breakthrough could reshape antibiotic research and unlock new drug discoveries.
Chromosome with Telomere and bubble floating on blue background - science and anti aging concept - 3D illustration
A team of researchers at Cornell University has made a groundbreaking discovery about transposons, or ‘jumping genes,’ revealing how these mobile DNA elements can target and insert themselves into the ends of bacterial chromosomes, known as telomeres. This finding has implications for biotechnology, drug development, and the broader understanding of bacterial evolution and antibiotic resistance.
Transposons are DNA segments capable of moving between different locations in the genome. They play a crucial role in bacterial adaptation, particularly in the spread of antibiotic resistance. In their latest study, published in Science, Cornell researchers found that transposons in bacteria with linear chromosomes, such as Streptomyces, can control telomeres, which are essential for chromosome stability and replication.
Bacteria are like these little tinkerers. They’re always collecting these mobile DNA pieces, and they’re making new functions all the time.
“This is a big part of their biology,” said Joseph Peters, senior author and professor of microbiology at Cornell. “Bacteria are like these little tinkerers. They’re always collecting these mobile DNA pieces, and they’re making new functions all the time – everything in antibiotic resistance is really about mobile genetic elements and almost always transposons that can move between bacteria.”
Using advanced genomic technologies, the researchers identified several families of transposons in Streptomyces and cyanobacteria that use unique mechanisms to insert themselves at the telomeres. The strategic placement of transposons at chromosome ends benefits both the transposon and the bacterial host, minimising the risk of disrupting essential genes and ensuring their own survival.
A survival strategy with major implications
One of the most striking findings was how transposons in Streptomyces were structured. Normally, transposons are flanked by sequences that direct their movement. However, those found at the telomeres had a distinct arrangement – one end was a traditional transposon sequence, while the other was the telomere itself. This adaptation effectively makes the transposon an integral part of the chromosome end.
“What it lets them do is become essential to the host, because they now control the telomere, and if the element got deleted along with this system, the host would die,” Peters explained.
Additionally, the study revealed a subfamily of telomere-targeting transposons that have co-opted a CRISPR system – a defence mechanism bacteria typically use to fight off viruses – to insert themselves into chromosome ends. This discovery reinforces earlier findings from Peters’ lab that transposons can repurpose CRISPR for mobility, presenting exciting new possibilities for genetic engineering. Unlike the widely used CRISPR-Cas9 system, these transposons may allow for the insertion of larger DNA segments, opening the door for new gene-editing applications.
Potential for drug discovery and beyond
Understanding how transposons function in Streptomyces is particularly important because this bacterial genus has historically been one of the most significant sources of antibiotics. Given that transposons drive bacterial evolution, they could provide vital clues for the discovery of new antibiotic compounds and other useful bioactive products.
We want to understand how these living organisms function, but then we want to see how we can use these systems for the betterment of humankind.
“Most of life on the planet is microbes, and specifically bacteria,” Peters said. “We want to understand how these living organisms function, but then we want to see how we can use these systems for the betterment of humankind.”
The research was supported by funding from the National Institutes of Health and the European Research Council.
With transposons continuing to shape bacterial genomes in unexpected ways, this study opens up new avenues for both fundamental microbiology and applied science, offering insights that could reshape genetic engineering and antibiotic research in the years to come.
This study was published in Science.