Horizontal gene transfer through introners

Overcoming Intron Barriers in Bacteria

Recent research has shown that genes can move from one organism to another through a process called horizontal gene transfer (HGT). This has helped bacteria evolve and adapt quickly. However, when genes from eukaryotes (organisms like plants, animals, and fungi) are transferred to bacteria, they often come with introns, non-coding parts of the gene that bacteria can’t easily process. This can make the gene non-functional in the bacteria. However, new studies show that bacteria can quickly overcome this challenge and activate these genes. 

Mechanisms for Gene Activation in Bacteria

In one study by Yuan, they investigated how bacteria can make genes with eukaryotic introns work. They discovered that although bacteria can transcribe these genes, the introns often cause translation issues. However, they found two ways bacteria can fix this:

1. Deleting part of the intron: this removes the problematic stop codons, allowing the gene to function.

2. Using the intron to create split proteins: in this case, the intron helps produce two smaller proteins that work together to restore the gene’s function.

This shows that bacteria can quickly adapt to new genes, even if they have introns, if the gene gives the bacteria an advantage.

Transposons and the Spread of Introners

A second study by Gozashti explored how transposons (mobile genetic elements) help spread introns across species. They found that these “introners” can move between species through HGT, making them a major source of new introns in eukaryotic organisms. Some of these introners are transferred with the help of giant viruses, which might act as a vehicle for moving genetic material between species. 

The Role of Intron Activation in Evolution and Biotechnology

Together, these studies demonstrate how flexible and fast-moving genetic material can be. Even though introns were once thought to be a major barrier to gene transfer, these findings show that bacteria can quickly evolve to use new genes, and eukaryotic organisms can gain introns through horizontal transfers, making their evolution even more complex. These insights are important for biotechnology, as they suggest ways to engineer genes with introns for use in bacteria.

Reference

Yuan, Wen, et al. "Rapid Functional Activation of Horizontally Transferred Eukaryotic

Intron-Containing Genes in the Bacterial Recipient." Nucleic Acids Research,

vol. 52, no. 16, 2024, pp. 9210–9223. PMC,

https://pmc.ncbi.nlm.nih.gov/articles/PMC11317163/.

Gozashti, Landen, et al. "Horizontal Transmission of Functionally Diverse

Transposons Is a Major Source of New Introns." Proceedings of the National

Academy of Sciences, vol. 122, no. 21, 2025, e2414761122. PNAS, https://www.pnas.org/doi/10.1073/pnas.2414761122.