Scientists from the University of California at Berkeley, for the first time in history, have edited the genome of a complex multicellular organism and added a fundamentally new function to it. Everything is like in fantastic works - ordinary fruit flies suddenly became invulnerable to toxins and at the same time deadly to predators. But most of all scientists admire not the result, but how it was obtained.
For almost all insects, the spurge plant is deadly poisonous, except for the monarch butterfly, which in the course of evolution has learned to accumulate its poison in its body without harm to itself. And if a predatory insect attacks a butterfly, it will be poisoned - this is such an effective defense mechanism. Scientists have found that the whole thing is in the mode of the sodium pump in the cells, which changes under the influence of milkweed poison, which leads ordinary insects to death.
Having studied the operation of this pump, they came to the conclusion that it is not difficult to "reprogram" it. To do this, it turned out to be enough to edit just one gene, more precisely, only three nucleotides in it. But the sequence is important - the first two mutations consistently increased resistance to the toxin, but the nervous system suffered. But the editing of the third nucleotide eliminated this effect. Using the CRISPR tool, the researchers edited the genome of the fruit flies, and they became resistant to the poison.
Observations showed that the milkweed resistance in flies increased 1000 times, and the effect persisted even during the transition from the larval stage to the adult. This did not greatly increase their chances of survival, since predators do not yet know that flies are now dangerous. But de facto, insects have acquired a new effective ability, and at the will of man. This opens up broad prospects for further genetic design of living things.