A report released by the National Academies of Sciences, Engineering and Medicine has revealed that the gene drive technique is promising but needs more research.
The danger lies in releasing organisms that have undergone the process of gene drive, but the Academies promote experiments to continue in laboratories.
The report named “Gene Drives on the Horizon” asks if there is a way of manipulating an insect’s genes, so it doesn’t spread disease. It was found out by researchers that certain elements of the DNA are almost guaranteed to pass from a parent organism to its offspring. The question is if it was possible to eliminate those genetic traits that are harmful to humans, for instance, the genetic elements that lead mosquitoes to spread diseases such as Zika and Dengue.
The gene drive is a DNA sequence that can cause mutations that are subsequently inherited by an organism with a certainty of 100 percent. All of the following children will display the driven gene mutation.
Although the results seem promising, researchers are still not sure about the implications of gene drive in the environment. They are confident that it would have some important impact on the ecosystem, which will affect other species, perhaps even allowing for the appearance of other diseases.
The process has been known for several years, but it is just now that researchers have realized that the driven gene modifications can spread throughout a whole species. The most effective techniques have also been just recently developed. Nowadays, scientists use a method known as CRISPR-Cas9.
It was suggested by Stuart Newman from the New York Medical College, that this technique would be the same that would allow armed forces to develop biological weapons.
Why is this not being implemented?
The report explains that there is not enough evidence to allow the release of gene drive modified specimens into the environment. There are many risk factors inherent to this type of technique, mainly the potential for escape and mutation, as genetic engineers have not been able to assess correctly whether the driven genes will be able to affect other organisms. Also, it is possible for a specimen to escape the target population, thus allowing for unprecedented events to occur.
For gene-drive modified organisms to be released there has to be a careful measuring of its ecosystem. The technique stands as very beneficial when in containment, specifically in environments of research and experimentation.
“There is insufficient evidence available at this time to support the release of gene drive modified organisms into the environment. However, the potential benefits of gene drives for basic and applied research are significant and justify proceeding with laboratory research and highly-controlled field trials,” the report reads.
But this wouldn’t be the first time that genetically-engineered species have been released to fight disease. California and Arizona scientists managed to block the gene of malaria in a strain of mosquitoes.
Oxitec, a British company, managed to modify the genes of Aedes Aedypti mosquitoes, so they die unless they receive a sufficient dose of antibiotics. These mosquitoes have been released to the environment, and they will pass the gene to most of their children. Field tests have been successful, as Brazil implemented the measure in May 2015. Brazil’s government saw a decrease in the number of dengue cases over the following months.
Still, researchers argue that it may not be the absolute solution to widespread infectious diseases such as dengue, Zika, malaria, and yellow fever. Some argue that, if 8 out of every 10 Aedes aegypti mosquitoes died, the remaining two would be able to develop and keep spreading the disease. It could also occur that another species starts to transmit the disease instead.
Real proof has to be found. To find evidence, large-scale tests must be carried out by specialized institutions. On the top of that, gene drive procedures are expensive, and they are not available for every country.
What’s to come for GM species
Gene drive has already been widely implemented in laboratories on fruit flies, yeast, corn, and mosquitoes. One of the experiments showed how a few yellow genetically-engineered fruit flies managed to turn all the contained population to that same color.
The first step is to prove that the “males only” gene can propagate throughout an entire mosquito population to make a significant impact in the fight against infectious diseases. Another measure that need they to prepare is some way to reverse the effect if anything went wrong, besides knowing the approximate amount of mosquitoes that they would have to release in the wild.
Field tests are mandatory for this type of research to take flight. There’s also the scenario of a dramatic decrease in the population of mosquitoes. Researchers need to ponder the overall impact of a species completely disappearing from the ecosystem.
Even if the Aedes aegypti has caused only trouble for the human species, it might play a key factor in the maintenance of flora and fauna. Sooner or later these tests will be made, as mosquitoes have proven to be a significant player in the transmission of infectious and potentially deadly diseases, especially in the last several months.
Source: National Academies of Sciences, Engineering, and Medicine