Gene engineers say they can deliver a stunning blow to malaria by modifying mosquitoes so that they no long hand on the parasite that causes the disease. The transgenic insects can add a new weapon to the arsenal of drugs and insecticides against a disease estimated to kill up to 2.7 million people a year, say a team led by Marcelo Jacobs-Lorena at caste western reserve university in Cleveland, Ohio. The technique attacks the microscopic parasite plasmodium at one of the key points in its complex cycle. Mosquitoes pick up the embryonic parasite by sucking up blood, its food, from an infected human. The parasite then lodges in the mosquito`s gut, where it develops into thousands of worm-like creatures called sporozoites. These then emerge into the mosquito`s saliva glands when the insect feeds again, it spits them out, thus infecting the next person.
The Jacobs-Lorena team created a strain of mosquitoes that carry a gene, 0which controls a peptide -- a short chain of Amino acid -- that prevents the sporozoites from moving from the gut to the saliva glands, thus blocking off the transmission phase of the cycle.
GM mosquitoes which had fed on infected mice were at least 80 per cent less effective at spreading the parasite than their non-modified cousins.

Bureau Report