Oily Coating Serves Dual Purpose

a fluffy white moth with antennae resembling bristles of a comb sits on a green leaf facing the camera

Biological Strategy

Silk moth

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Sense Chemicals (Odor, Taste, etc.) From the Environment

Chemicals are important for signaling and communication among living systems, either intentionally (such as when two living systems try to find one another) or unintentionally (such as when a plant emits a chemical signal that an herbivore can use to find a tasty bite). They are also important for other uses, such as navigating or finding sources for minerals. But chemical signals are often relatively weak and disperse when moving through water or gases. Therefore, detecting them requires specialized abilities, including a way to determine where they are coming from. A well known example of sensing chemicals can be seen in ants following a pheromone trail laid down by others in their colony to locate a quality and abundant food source.

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Capture, Absorb, or Filter Chemical Entities

Living systems often require chemical elements and chemical compounds, including complex sugars, proteins, and odor-making compounds, to perform critical activities. These compounds exist in various states–solid, liquid, and gas–and are ubiquitous in soil, water, and air. This requires that living systems not only have ways to capture, absorb, or filter them, but also ways to differentiate among them, selecting those that are valuable or harmful. For example, mangrove trees live with their roots in salty water and sediments. Various mangrove species have different strategies for removing salt from the water they take in so that their tissues can use the fresh water.

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Insects

Class Insecta (“an insect”): Flies, ants, beetles, cockroaches, fleas, dragonflies

Insects are the most abundant arthropods—they make up 90% of the animals in the phylum. They’re found everywhere on earth except the deep ocean, and scientists estimate there are millions of insects not yet described. Most live on land, but many live in freshwater or saltwater marshes for part of their life cycles. Insects have three distinct body sections: a head, which has specialized mouthparts, a thorax, which has jointed legs, and an abdomen. They have well-developed nervous and sensory systems, and are the only invertebrate that can fly, thanks to their lightweight exoskeletons and small size.

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The antennae of male silk moths distribute chemicals by having an oily coating that serves a dual purpose by binding to lipid-loving female pheromones and transporting them to nerve cells.

Image: Chris Burke /

A special coating on the nanotunnels of a silk moths antenna is the inspiration for a similar oily layer on synthetic nanopores, tiny measurement devices. University of Michigan researchers led the development of this improved technology, and theyre using it to gain new insights into Alzheimers and other similar neurodegenerative diseases.

Image: Chris Burke /

This is a closeup of a nanotunnel in a silk moths antenna. Pheromones travel through these tunnels, telling the male moth that a female is nearby.

“[A] coating on the male silk moth’s antenna…helps
it smell nearby female moths. The coating catches pheromone molecules
in the air and carries them through nanotunnels in the exoskeleton to
nerve cells that send a message to the bug’s brain. ‘These
pheromones are lipophilic. They like to bind to lipids, or fat-like
materials. So they get trapped and concentrated on the surface of this
lipid layer in the silk moth. The layer greases the movement of the
pheromones to the place where they need to be,’ [according to Michael
Mayer, an associate professor in the University of Michigan’s
departments of Biomedical Engineering and Chemical Engineering]” (Moore
2011:1)

Last Updated August 18, 2016

References

Journal article

Controlling protein translocation through nanopores with bio-inspired fluid walls

Yusko EC; Johnson JM; Majd S; Prangkio P; Rollings RC; Jiali L; Yang J; Mayer M

Silk moth's antenna inspires new nanotech tool with applications in Alzheimer's research

Moore NC

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