AsianScientist (May 1, 2019) – Scientists in Japan have found the gene responsible for the formation of nanopores in fruit flies, with implications on how the insects sense chemical cues in the air. The research is published in Current Biology.
Nature is a treasure trove of unique patterns and structures that form at the nanometer scale. For example, in insects, the cuticle covering sensilla—olfactory organs found on the antennas of insects—has small pores with diameters between 50 and 200 nanometers.
Such nanopores are believed to function as filters that allow odorant molecules to enter but prevent the entry of larger airborne particles and help the insects avoid liquid loss. The ability to smell airborne odorants contributes to insects’ ability to search for foods, mates and other environmental cues.
To find out more about how these pores develop, researchers led by Professor Shigeo Hayashi at the RIKEN Center for Biosystems Dynamics Research, Japan, observed the developing pupa of fruit flies in detail using transmission electron microscopy. They found that the cuticular nanopores in the fruit fly’s olfactory sensilla originate from a curved ultrathin film that is formed in the outermost envelope layer of the cuticle, and secreted from specialized protrusions in the plasma membrane of the hair-forming cell.
Using next-generation genome sequencing, they discovered a gene—named gore-tex—responsible for the formation of the pores. Deleting the gene did not lead to any deficits in morphology or affect the survival of flies, but it hampered the formation of pores on the sensilla and the flies’ ability to smell.
Further analyses revealed that the gore-tex gene is a member of the gene family called Osiris, and encodes a protein that is essential for envelope curvature, nanopore formation and odor receptivity. The gene is expressed specifically in developing olfactory hair-forming cells.
“Our study revealed the elements required for the development of nanopores to allow odor reception, and identified Osiris genes as a platform for investigating the evolution of surface nanofabrication in insects,” said Hayashi. “We hope that studies like this will help us understand how nature builds these fascinating nanostructures that allow living creatures to acquire many specialized functions.”
The article can be found at: Ando et al. (2019) Nanopore Formation in the Cuticle of an Insect Olfactory Sensillum.
Source: RIKEN; Photo: Shutterstock.
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