Useful pests
Scientists have created genetically modified pests that destroy their own kind
The development will help to use less toxic insecticides
Natalia Pelezneva, Naked Science
Researchers from Cornell University in the USA have announced that this year they can go through the final stages of an experiment with a genetically modified cabbage moth (Plutella xylostella). It is a pest of garden cabbage, broccoli and other cruciferous plants, widespread all over the world. According to entomologist Anthony Shelton, four to five billion dollars are spent annually around the world to fight cabbage moth.
Insecticides of various types, such as pyrethrins and their synthetic analogues, are usually used to control the pest. These drugs are toxic, so scientists are looking for new ways to kill insects.
Anthony Shelton and his colleagues proposed one of these methods back in 2015. They have created genetically modified insects that will be able to limit the reproduction of their own species. In insects, lethal alleles are activated, which cause the death of females at an early stage — before mating.
Mating cabbage moth, photo Dan Olmstead
The expression of a particular gene is activated by the tTA protein, a tetracycline-controlled transactivator. To obtain this protein, it is necessary to combine the TetR repressor protein and the activator domain of the VP16 protein. The TTA protein binds to a specific sequence of DNA nucleotides and can control gene expression. The scientists used a variant of the technology called Tet-On: the protein binds to DNA only in the presence of tetracycline or its analogues. To "start" the process, the larvae are exposed to tetracycline. For the first time, the technology was tested on fruit flies, and later it was possible to use it with other insect species.
The females of the modified pests die before mating, and the males mate with the females of the wild cabbage moth, spreading the lethal gene. Thus, in the next generation, the number of females capable of producing offspring decreases.
If scientists receive permission from the US Department of Agriculture, they will be able to test the development this summer.
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31.05.2017