New! Sign up for our free email newsletter.
Science News
from research organizations

Stinky, bitter, and painful: A novel insect repellent attacks multiple sensory pathways

Date:
December 22, 2023
Source:
National Institutes of Natural Sciences
Summary:
Researchers found that a Transient Receptor Potential (TRP) A1 stimulant, 2-methylthiazoline (2MT), act as a potent insect repellent in Drosophila. 2MT induces aversive behaviors via olfactory, gustatory, and nociceptive sensory pathways. 2MT acts on TRPA1 through specific cysteine residues that are conserved across many insect pest species.
Share:
FULL STORY

Crop damage in agriculture and the transmission of vector-borne diseases by insect pests have become a worldwide threat. Chemical treatments such as insecticides and repellents have been a major strategy against insect pests for centuries. Due to limited understanding of mechanisms of insect avoidance behavior, however, development of insect repellents has been delayed. To discover compounds that effectively repel insect pests, it is important to focus on key molecules associated with sensory, particularly aversive, responses. In this study, researchers identified a compound that induces robust aversive responses through multiple sensory pathways in the fruit fly, Drosophila melanogaster.

Among sensory receptors, Transient Receptor Potential (TRP) cation channels play a key role in nocifensive behaviors to various stimuli in many insect species. Particularly, TRPA1 channel has been extensively studied as it is activated by various hazardous chemicals. Therefore, insect TRPA1 stimulants are promising leads for novel repellents with a broad spectrum. Takaaki Sokabe and his colleagues at the National Institute for Physiological Sciences/the Exploratory Research Center on Life and Living Systems (ExCELLS) found that 2-methylthiazoline (2MT), an analog of a volatile compound found in fox urine, repels flies effectively, and revealed the molecular and cellular mechanisms of 2MT-induced aversions in the fly. They recently published their findings in Frontiers in Molecular Neuroscience.

"2MT is reported to evoke innate fear responses in mice via TRPA1, therefore we expected that the chemical possibly have an aversive effect on insects," Sokabe says. "And it worked terrifically more than our expectation."

Fly's avoidance behaviors revealed that 2MT stimulates multiple sensory modalities: 2MT vapor acts on odorant receptors (ORs) in an olfactory pathway, and direct contact to 2MT activates TRPA1 in taste and nociceptive pathways. This resulted in apparent escaping from chemical source of male flies and avoidance of egg laying of female flies. Furthermore, The researchers demonstrated that TRPA1 is activated by 2MT through the direct interaction of 2MT to specific two amino acids in TRPA1.

"The action of 2MT on multiple sensory pathways seems to be a key for its high effectiveness," says Takaaki Sokabe. "Because the amino acids essential for TRPA1 activation are highly conserved across a wide range of insect species, including agricultural pests and disease vectors, it will be important to test 2MT on many other insect pests to evaluate the spectrum."

This new work could promote the development of novel insect repellents by focusing on TRP channels and other types of receptors as promising targets.


Story Source:

Materials provided by National Institutes of Natural Sciences. Note: Content may be edited for style and length.


Journal Reference:

  1. Shoma Sato, Aliyu Mudassir Magaji, Makoto Tominaga, Takaaki Sokabe. Avoidance of thiazoline compound depends on multiple sensory pathways mediated by TrpA1 and ORs in Drosophila. Frontiers in Molecular Neuroscience, 2023; 16 DOI: 10.3389/fnmol.2023.1249715

Cite This Page:

National Institutes of Natural Sciences. "Stinky, bitter, and painful: A novel insect repellent attacks multiple sensory pathways." ScienceDaily. ScienceDaily, 22 December 2023. <www.sciencedaily.com/releases/2023/12/231222145432.htm>.
National Institutes of Natural Sciences. (2023, December 22). Stinky, bitter, and painful: A novel insect repellent attacks multiple sensory pathways. ScienceDaily. Retrieved March 4, 2024 from www.sciencedaily.com/releases/2023/12/231222145432.htm
National Institutes of Natural Sciences. "Stinky, bitter, and painful: A novel insect repellent attacks multiple sensory pathways." ScienceDaily. www.sciencedaily.com/releases/2023/12/231222145432.htm (accessed March 4, 2024).

Explore More
from ScienceDaily

RELATED STORIES