‘Spidey’ gene might unlock mystery of waxy insects

An international team of scientists, led by University of Hawaii at Mānoa researcher Dr. Joanne Yew, has identified a gene in fruit flies (Drosophila melanogaster, also known as vinegar flies) responsible for the insect’s waterproof coating, which provides protection from microbes and environmental stress. The team nicknamed the gene “spidey,” and announced the findings in a recently published study in PLoS Genetics.

“When we knocked out spidey in adult flies, the flies exhibited several striking features,” explains Dr. Yew, an assistant researcher based in the Pacific Biosciences Research Center of UH Mānoa’s School of Ocean and Earth Science and Technology. “Their lifespan was shortened by about 50 percent. They lost almost all of their waxy coating, and the flies frequently got stuck to the sides of the plastic vials and were unable to free themselves. This last feature was reminiscent of the comic book character Spider-Man, which is why we named the gene spidey.”

Spidey is important for regulating levels of a steroid hormone, which maintains wax-producing cells. This hormone was already known to play a crucial role in the development and metamorphosis of fly larvae. The researchers did not expect steroid hormones would play such a central role in maintaining adult tissues, such as the wax-producing cells.

“We did this work in vinegar flies, which is a major model organism,” Dr. Yew says. “From here, perhaps we can bridge to [other] pest species.”

Yew and her colleagues now plan to knock out spidey in oriental fruit flies (Bactrocera dorsalis), Mediterranean fruit flies (Ceratitis capitata) and melon flies (B. cucurbitae), which are a major threat to agriculture, and possibly mosquitoes, to see whether they lose their waterproofing ability like the vinegar flies. She says it would be at least four more years of more research, testing and government approvals before the discovery could be used as a pest control.

The work was funded by the Singapore National Research Foundation, the UH Mānoa Office of the Vice Chancellor for Research and the UH Mānoa Pacific Biosciences Research Center.