Edited mosquito genes to eradicate zika – PanamaOn

The mosquitoes, like other insects are vectors of human diseases, parasites or viruses to transmit through their bites. Dengue, chikungunya and zika, among others, are some of the diseases that affect millions of people worldwide and for which there is no vaccine yet.

In their absence, a way to combat spread of these diseases is to control or eradicate the vector, in this case, the female mosquito Aedes aegypti that suck blood.

In the case of dengue have already been released sterile modified mosquitoes that have shown some success. But many of these techniques are expensive

The bug has generated an international public health emergency by the transmission of Zika virus especially in South America, according to data from the World Health Organization (WHO). Of particular concern is its possible relationship with the thousands of cases detected in newborns and neonatal neurological abnormalities such as microcephaly.

Although already launched the first control methods, especially spraying, experts wHO recommended in a filing to increase efforts to control the vector and reduce mosquito densities to a level in which the virus transmissions interrupted.

scientists working for years in the design of genetic strategies to limit the spread of these diseases caused by female mosquitoes, which are hematophagous (they feed on the blood of other animals) and therefore responsible for the bites. Males are harmless sucking nectar.

In the case of dengue have already been released sterile modified mosquitoes that have shown some success. But many of these techniques are expensive and sometimes unrealistic, because you need released long-term, difficult to implement on a large scale.

According to an article published in the journal Trends in Parasitology , a more effective and inexpensive strategy would handle the genes of manhood with the CRISPR-Cas9 system, a molecular scissors enable even mosquitoes, introduce mutations easily and accurately at any genomic landmark.

“by using the CRISPR-Cas9 system all mosquitoes could be male in each generation,” says Zach Adelman

“by using the CRISPR-Cas9 system all mosquitoes could be male in each generation,” says SINC Zach Adelman, an entomologist at Virginia Tech (USA) and lead author of the paper. To achieve this, the scientist aims to combine art with the genetic determinant of sex and allows change of females to males.

In a study published in Science in May 2015 Adelman and Zhijian Tu, the same US institute manipulated the expression of the genes of embryos of females with the gene that determines sex, called Nix, which triggered the development of external genitalia and internal male.

However, the use of this gene would not be enough: “Only half of the offspring would be male,” says the scientist. With editing capabilities gene CRISPR-Cas9 and Nix gene it is achieved transform sucking females blood into harmless males, and thus prevent the spread of disease.

“By combining management strategies genes with sex reassignment, a small number of males released could lead to a wave of generations of single males, which would allow the eventual elimination of the vector and therefore to the spread of disease-causing agents ” Sync clarifies the expert.

Although scientists are already testing these techniques, Adelman admits that further experiments are needed in the laboratory before applying these systems and know how long it would take to have a harmless mosquito population . But “it is definitely possible,” ditch.

However, ethical and safety concerns generated by these practices, such as the accidental release of females during pruebas-, other questions come together. Scientists have not yet clear how the gene controls Nix sex determination in mosquitoes and if these genetic factors are conserved between different species that transmit diseases. In addition, the effectiveness and long-term stability of the CRISPR-Cas9 mosquitoes system remains unknown.