Mosquito Genes

Mosquito Genes May Explain Why Some Are Prone To Bites

The Aedes aegypti mosquito is the primary species for transmitting dangerous pathogens such as Zika, dengue and yellow fever, infecting hundreds of millions of people around the world every year.

Many scientists think that having a better understanding of the insect’s genome—the complete set of genetic material in an organism—could help to reduce infections. To that end, an international team of researchers has mapped the genome of Aedes aegypti, uncovering several new genes—including some that could explain why the mosquitoes prefer biting certain people.

According to Rašić, identifying genes such as these could help researchers curb disease transmission, by using a variety of methods such as genetically modifying mosquito populations.

“Once we know the candidates, that might determine what makes someone more resistant or more attractive to the mosquito, we can manipulate the genes,” she said. “One of the key things that we want to achieve is to modify these mosquitoes in a way that will help control them.”

Until recently, scientists only had only incomplete fragments of the mosquito’s genome to work with, hampering research into the species.

“The genome was in so many pieces that we weren’t sure how they fit together, and we also weren’t sure that it was complete,” Benjamin Matthews, an author of the study from The Rockefeller University, said in a statement. “And if you can’t trust that the DNA sequence was correctly assembled, you’re not going to get very far.”

This new information could help researchers to develop novel insect repellants that interfere with the mosquito’s ability to find and bite us.

The team also found that some mosquitoes had multiple copies of genes that code for glutathione S-transferase (GST), an enzyme that neutralizes the toxic effects of insecticides. This discovery indicates that A. aegypti is evolving to protect itself against man-made toxins, according to Matthews, but now scientists may be able to create new insecticides that can kill even resistant mosquitoes.

Aside from enabling the development of new techniques to kill or repel the mosquito, the new research will also benefit efforts to genetically modify populations of A. aegypti. Because only the females of the species feast on blood, reducing their number would mitigate disease transmission rates.

By looking at the genetic information, the team was able to pinpoint genes responsible for determining the sex of a mosquito, a discovery that could be used to engineer male-only populations.

“Once the genome was publicly available, people started digging into it,” Matthews said. “Dozens, if not hundreds, of labs have already used it in their work, and that number will only grow with the publication of our paper.”