Small male Drosophila melanogaster fly. Credit: André Karwath
Key points:
- Researchers analyzed the gene expression patterns of five key scent-detecting tissues across six different Drosophila species to delve deeper into the molecular basis of smell.
- Many of the genes were uniform across fly species, but the team still identified thousands of genes expression changes and several sex differences that contribute to unique olfactory landscapes of different species.
- The findings provide a new perspective into the general principles of sensory system evolution.
Fruit flies have more complex sensory evolution than previously thought. A new study, published in Nature Communications, uncovers surprising results about how these insects adapt their senses to different environments.
Researchers analyzed the gene expression patterns of five key scent-detecting tissues across six different Drosophila species. This experimental design allowed them to delve deeper than ever before into the molecular basis of smell.
The prevalence of “stabilizing selection”—a force that keeps genes expressed at the same levels across generations—was a key discovery. However, within this stability, researchers still identified thousands of genes that underwent significant changes in expression, which shapes the unique olfactory landscapes of different fly species.
“It is like finding hidden islands of diversity within a vast ocean of uniformity,” said principal author Roman Arguello of Queen Mary University of London. “These changes in gene expression tell us about the evolution of new smells, new sensitivities, and even new ways of using scent to navigate the world.”
The team also identified differences between the sexes indicating that males and females experience the world through different olfactory lenses. They found an excess of male-biased gene expression in the front legs of D. melanogaster that point toward the limbs’ role in male-specific scent detection.
Although the study focused on fruit flies, the findings provide valuable new perspective into the general principles of sensory system evolution and clues into how animals, including humans, perceive their chemical environments.