# Introns increase gene expression in Caenorhabditis elegans by a mechanism that must be at least partly different than in plants

## TL;DR

Introns in nematodes boost gene expression more consistently than in plants, suggesting different mechanisms are at play.

## Contribution

The study reveals that introns in nematodes consistently increase gene expression, unlike in plants, indicating a different underlying mechanism.

## Key findings

- Introns near the gene start boost expression most in nematodes.
- Ten introns tested increased mRNA accumulation 10- to 17-fold in nematodes.
- Introns in plants show more variable effects on expression compared to nematodes.

## Abstract

The wide diversity of organisms in which introns stimulate gene expression suggests that this is an ancient phenomenon. However, the mechanisms through which introns boost expression remain poorly understood, and the degree the which the action of introns is evolutionarily conserved is unknown. Here we compared the effect on expression of introns at different positions and tested ten different introns at the same location in a reporter gene in single-copy transgenic nematodes. The introns boosted expression most when near the start of the gene, as previously observed in several organisms. All ten introns tested at the same position increased mRNA accumulation 10- to 17-fold, in contrast to plants where introns vary widely in their effect on expression and relatively few increase mRNA levels 10-fold or more. These results suggest that some aspects of the mechanisms through which introns boost expression are fundamentally different in nematodes and plants.

The online version contains supplementary material available at 10.1038/s41598-025-99739-6.