Moscerini and engineer fish transform the toxic methylmercurium for human consumers into an harmless form that evaporates quickly.
The weapon to get rid of the Metilmercurioa toxic pollutant taken by man through nutrition could come from the animals themselves. A group of Australian scientists has in fact engineered two organisms often involved in biology studies, fruit midges (Drosophile) and zebrafish (fresh water fish) to transform methylmercurium into an harmless gas easily dispersible in the environment . Their success is described in an article published on Nature Communications.
Worse for predators. Mercury emissions deriving from waste or coal combustion processes they deposit in watery ecosystemswhere the activity of some types of bacteria produces Metilmercurio (Mehg), the most common organic form of organic mercury in the food chain.
Metilmercurio has the characteristic of not being quickly eliminated by the organisms that contamine. For this reason It accumulates in gradually higher concentrations As you move on to the next level of the food chain, proceeding from below to the above (first in the plankton, then in macroinvertebrates, then in herbivorous fish, then in piscivori fish, finally in animals that feed on large fish, such as the ‘man).
Harmful effects. This accumulation process is said Biomagnification or bioamplification: large predators such as swordfish, sharks (grooves, verdesque, emery), red tuna, patch and nose, at the highest levels of the food chain, are more likely to contain high concentrations of methylmercurium in their fabrics. This substance that can cross the placenta and the hematencephalic barrier is particularly toxic for the nervous system during development. Therefore the consumption of fish that contain in quantity is therefore not recommended for pregnant women and children.
The danger, evaporated. A research team led by scientists from Macquarie University of Sydney has modified the DNA of fruit moscerini (Drosophila melanogaster) and zebrafish By inserting genes of bacteria capable of producing two enzymes which, together, convert the methylmercurio into elementary mercurywhich evaporates from animals in the form of gas. “When we tested the modified animals, we discovered that not only they had less than half of the mercury in their bodies, but that most of the mercury was in a much less bioavailable form of the Metilmercurio”, explains Kate Yepper, the first author of the study. By bioavailability we mean the degree of absorption of a substance by a living organism.
It can be done, but … The research is still preliminary: it will be necessary to deepen this type of studies, for example by ensuring that the modified organisms are unable to spread in an uncontrolled way in nature.
