Mosquito researchers may have hatched a new plan to control the bloodsuckers: Break their eggshells.
A protein called eggshell organizing factor 1, or EOF1, is necessary for some mosquito species’ eggs and embryos to develop properly, a new study finds. Genetically disrupting production of that protein in Aedes aegypti mosquitoes caused about 60 percent of their normally dark eggshells to be pale. And shells lacking EOF1 often collapsed and were more porous than normal. In experiments, almost no mosquito embryos in the EOF1-disrupted eggs hatched into larvae, researchers report January 8 in PLOS Biology.
EOF1 is produced only by Aedes, Anopheles and Culex mosquito species, biochemist Jun Isoe of the University of Arizona in Tucson and colleagues discovered. Those varieties of mosquitoes can transmit life-threatening diseases such as malaria, Zika, dengue and West Nile virus (SN: 11/10/18, p. 22). The protein could be a good target for genetic engineering techniques or insecticides, which may help control populations of disease-carrying mosquitoes without killing harmless insects, the researchers speculate.
In these scanning electron micrograph images, the shells of Aedes aegypti eggs lacking a protein called EOF1 (right column) have round bumps that are six times as large as those on shells with normal amounts of the protein (left column). The abnormal eggshells are also leaky, fragile and often collapse.
“This is truly outside-the-box thinking, and I like that,” says entomologist Joe Conlon, a technical adviser for the American Mosquito Control Association, an organization based in Mount Laurel, N.J., that helps individuals, companies and public health agencies control mosquitoes and other disease-spreading insects.
But many hurdles stand between the research and creating an effective mosquito-control strategy based on EOF1, Conlon says. The genetic technique that the scientists used to disrupt production of the protein is too cumbersome for widespread use, for example, and a chemical to disable EOF1 specifically has yet to be found. Still, knowing more about mosquito reproduction may also prove helpful in other ways, he says.