To fight malaria, we now have genetic weapons that can track and kill

Jun 17, 2014 by Sanjeev Krishna
Let them kill no more. Credit: photonquantique, CC BY-NC-ND

Every year malaria kills more than 600,000, which is a little less than the population of Bhutan. There are some simple solutions to control the disease, but keeping the numbers of mosquitoes with malarial parasites down remains a challenge.

The problem is that current control measures can wane in effectiveness as adapt. Discovering new ways to reduce mosquito numbers is therefore a high priority. An area where such advances are being made is genetics, and two recent studies are good examples of things to come.

Sex talk

Reducing the number of , which are the transmitters of the malarial parasite, can drastically reduce the spread of the disease. In a study published in Nature Communications, researchers at Imperial College London are able to do that by using an that affects DNA.

Their laboratory results show that, within a few generations, whole colonies of mosquitoes can disappear when they use this enzyme. The enzyme selectively shreds the DNA of female mosquito, affecting those bits involved in reproduction (in particular, the X chromosome). Its offspring then are nearly all male, leading to the collapse of the whole population.

Modifying the enzyme to damage the specific DNA took some time, and relied upon previous results that were initially obtained by curiosity-driven work. However, this new and successful application in the lab means field studies can begin soon.

Sleeping sickness in cattle, which is caused by tsetse flies, was eradicated from Zanzibar by the release of sterile male tsetse flies. But this was a costly and logistically demanding exercise that needed the saturation of a large area with nearly 10m sterile male flies produced by radiation treatment. The enzyme treatment might prove more cost effective, even though this is a different mosquito vector. It also gives more support to those in favour of .

Genetic barcodes

Resistance to malarial drug patterns vary by geography. It would prove very useful if researchers are able to pinpoint the origin of a particular malarial strain, and researchers at the London School of Tropical Hygiene and Medicine have developed such a tool using genetic "barcodes".

To do this they analysed the genomes of more than 700 parasites found in Africa, Southeast Asia and Latin America. Their report, also published in Nature Communications, found that most of the genome wasn't useful, but the bits of DNA in the mitochondria (the cell's powerhouse) and the apicoplast (a remnant of the plant cell found in the parasites) gave enough unique information to create a barcoding system.

The upshot of this quirk is that the barcoding system should last and get better as more genetic data is collected. This is because these bits of the DNA won't change much. They are passed down from mother to kids without recombining, unlike the rest of the DNA.

It is not enough to develop a new drug to replace a failing one, or discover another insecticide in the face of resistance in mosquitoes. Such imaginative technologies to reduce the enormous global footprint of are needed. With genetic tools, we have taken the fight against malaria to the molecular level.

Explore further: Scientists wipe out malaria-carrying mosquitoes in the lab by creating male-only offspring

add to favorites email to friend print save as pdf

Related Stories

Infection in malaria-transmitting mosquito discovered

Jun 06, 2014

Researchers have found the first evidence of an intercellular bacterial infection in natural populations of two species of Anopheles mosquitoes, the major vectors of malaria in Africa. The infection, called ...

Recommended for you

Scientists see how plants optimize their repair

10 hours ago

Researchers led by a Washington State University biologist have found the optimal mechanism by which plants heal the botanical equivalent of a bad sunburn. Their work, published in the Proceedings of the Na ...

Structure of an iron-transport protein revealed

16 hours ago

For the first time, the three dimensional structure of the protein that is essential for iron import into cells, has been elucidated. Biochemists of the University of Zurich have paved the way towards a better ...

Over-organizing repair cells set the stage for fibrosis

17 hours ago

The excessive activity of repair cells in the early stages of tissue recovery sets the stage for fibrosis by priming the activation of an important growth factor, according to a study in The Journal of Ce ...

User comments : 0