Anti-Malaria Mosquitoes!!

Despite decades of work controlling the spread of malaria, the disease still claims more than 400,000 lives each year. Researchers from the University of California Irvine have developed a tool that might put a big dent in that number. Using a technology called gene drive, scientists have created a genetically modified type of mosquito that is incapable of transmitting malaria to humans and can convert wild populations in just a few generations.

Gene drive is a term that describes pushing specific modifications across a population of organisms. The team used a genetic editing procedure called Crispr-Cas9 to add a gene for malaria antibodies to the eggs of Anopheles stephensi mosquitoes. These insects are one of the primary carriers of malaria, but they won’t transmit it to humans when they bite if their DNA causes them to produce an antibody for malaria parasites. This is particularly cool as insects don’t actually have any antibodies of their own.

The revolutionary part of gene drive comes from the way Crispr-Cas9 adds genes to DNA. A single modified gene in a germline cell has a 50% chance of being passed down to offspring — you get half your genes from your father and half from your mother. This technique is able to add two copies of the gene, resulting in a much higher chance of inheritance. In testing the modified mosquitos in the lab, the team found 99.5% of the offspring had the modified gene. They also added a handy marker gene that causes the insect to have fluorescent red eyes.

It’s important to note, these insects are confined to a lab and aren’t considered ready for use in the real world. The goal of gene drive is to aggressively convert wild type populations to the new genotype, so you want to make sure there are no unintended consequences from your genetic modifications. A number of scientists published a letter in the journal Science recently to urge caution in the development of these organisms. They will need to be extensively tested in controlled environments before they could ever be released.

As mosquitoes continue to adapt to insecticides, going after their genes might be the best way to save lives. Everyone agrees it’s worth pursuing, so long as we’re careful.