Illustration of a silkworm's antennae with scent and gene symbols.

Decoding the Silkworm's Secrets: How Science Unravels the Mystery of Smell

Rhea Morgan in Science & Nature September 2025 • 4 min read.

"New research unveils how the humble silkworm's sense of smell is surprisingly similar to our own, and what it reveals about the effects of domestication."

The world of insects might seem far removed from our own, but a recent study published in BMC Genomics offers a surprising parallel: the silkworm's sense of smell. Scientists have been delving into the silkworm's olfactory system, comparing its genetic makeup to its wild counterparts. The goal is to understand how domestication, the process of taming wild animals for human use, has changed these tiny creatures. What they've found offers a glimpse into the fascinating world of smell, and how it's shaped by both nature and nurture.

The silkworm, a creature whose life is intertwined with the production of silk, has been domesticated for thousands of years. This long history has led to some intriguing changes, particularly in how these insects perceive their environment. The researchers focused on the silkworm's antennae, the primary organs for detecting scents. By comparing the genetic makeup of the domesticated silkworm with its wild cousins, they hoped to pinpoint the mechanisms behind any changes in olfactory abilities.

This investigation does more than simply observe; it unravels the mechanics behind the silkworm's sensory experiences. The findings reveal that the genes responsible for smell are not merely static blueprints. They are dynamic, evolving entities that respond to environmental pressures. This has far-reaching implications, not just for understanding the silkworm, but also for gaining a deeper appreciation of the intricate dance between genes, environment, and behavior in the animal kingdom.

The Nose Knows: Unpacking the Silkworm's Olfactory System

Illustration of a silkworm's antennae with scent and gene symbols.

At the heart of the study lies the silkworm's olfactory system, a complex network of genes and proteins. The researchers scrutinized the antennae, comparing the genetic information from domesticated silkworms to their wild relatives. They were particularly interested in genes related to smell, such as those encoding olfactory receptors (ORs) and odorant-degrading enzymes (ODEs).

The findings were quite telling. The team discovered a significant difference in gene expression between the two groups. Many of the genes linked to smell were less active in the domesticated silkworms. This observation suggests that the silkworm's ability to detect scents may have diminished during the domestication process, raising interesting questions about how selective pressures influence sensory perception.

Olfactory Receptors (ORs): These proteins are the front-line soldiers, the very things that help a silkworm smell a scent.
Odorant-Degrading Enzymes (ODEs): Think of these as the clean-up crew. They break down scents to keep the sensory system from being overloaded.
The Antennae: These are the primary sensory organs, like the nose of the insect world.

The study didn't stop at the basic differences. It also delved into the genetic makeup of the individual silkworms. The researchers found that the genes in the domesticated silkworms showed a higher rate of change. This suggests that the genes, no longer under the same pressures, were evolving more freely. This offers an insight into the changes that come with domestication. The silkworm's reduced reliance on its sense of smell, thanks to being in a controlled environment, may have led to a relaxation of the selection pressures.

A Bigger Picture: Implications for Science and Beyond

This study's implications stretch far beyond the silkworm. It provides a valuable case study of how domestication can reshape an animal's sensory world. By understanding the effects of environmental pressures on sensory systems, we gain a better understanding of the relationship between genes, behavior, and environment. The research highlights the evolutionary adaptability and the delicate balance within ecosystems.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1186/s12864-018-5172-1, Alternate LINK

Title: Evidence Of Peripheral Olfactory Impairment In The Domestic Silkworms: Insight From The Comparative Transcriptome And Population Genetics

Subject: Genetics

Journal: BMC Genomics

Publisher: Springer Science and Business Media LLC

Authors: Chuan-Zhen Qiu, Qiu-Zhong Zhou, Ting-Ting Liu, Shou-Min Fang, Ya-Wang Wang, Xin Fang, Chun-Li Huang, Quan-You Yu, Chun-Hong Chen, Ze Zhang

Published: 2018-11-01

Everything You Need To Know

How does the silkworm's sense of smell compare to that of other animals, like humans?

Research indicates that the silkworm's olfactory system shares surprising similarities with other animals, including humans. This is evident through the examination of genes responsible for smell such as Olfactory Receptors (ORs) and Odorant-Degrading Enzymes (ODEs). The similarity provides insights into how senses and evolution work across different species. However, the exact extent and nuances of these similarities require further investigation to fully understand the comparative complexities of olfactory perception.

What are Olfactory Receptors (ORs) and Odorant-Degrading Enzymes (ODEs), and what roles do they play in a silkworm's sense of smell?

Olfactory Receptors (ORs) are proteins that enable the silkworm to detect scents. They are the initial point of contact for odor molecules. Odorant-Degrading Enzymes (ODEs) break down scent molecules after they have been detected. This breakdown prevents sensory overload and allows the silkworm to process new scents effectively. Both ORs and ODEs are essential for the silkworm to navigate its environment and respond to stimuli.

How has domestication affected the silkworm's sense of smell, and what specific changes have been observed in their olfactory system?

Domestication has notably impacted the silkworm's sense of smell. Research indicates that genes linked to smell, such as those encoding Olfactory Receptors (ORs) and Odorant-Degrading Enzymes (ODEs), are less active in domesticated silkworms compared to their wild counterparts. This suggests a diminished ability to detect scents due to the controlled environment of domestication, where the need for a strong sense of smell is reduced.

Why did researchers focus on the antennae of silkworms when studying their sense of smell?

Researchers focused on the antennae because they are the primary sensory organs for detecting scents in silkworms. The antennae contain the Olfactory Receptors (ORs) necessary for the silkworm to perceive its environment through smell. By examining the genetic makeup and gene expression within the antennae, scientists can gain direct insights into how the olfactory system functions and how it has been affected by domestication.

What are the broader implications of studying the silkworm's olfactory system for understanding evolution and the relationship between genes, behavior, and the environment?

Studying the silkworm's olfactory system provides valuable insights into how domestication can reshape an animal's sensory world. It highlights the evolutionary adaptability and the delicate balance within ecosystems. By examining changes in genes like those for Olfactory Receptors (ORs) and Odorant-Degrading Enzymes (ODEs), we can better understand how environmental pressures influence sensory systems, genes, and behavior. This offers a deeper appreciation of the intricate relationship between genes, environment, and behavior in the animal kingdom, which can be applied to other species as well.