Breaking the cycle. interfering with mosquito proteins might counteract the malaria parasite.
As spreads malaria resistant to drugs, researchers have intensified their search for new ways to fight against the scourge of mosquitoes. Now they have identified three genes that control how the mosquitoes themselves fight the malaria parasite. The results indicate that drugs or genetic changes that Beef immune response of mosquitoes could one day help stop malaria spreading.
When a mosquito bites a person infected with malaria, it ingests unicellular Plasmodium parasites that cause disease. Within 10 minutes the matt parasites; in a day it is fixed in the wall of the gut of the mosquito; and after 3 weeks he made his way to the salivary glands of the insect, ready to jump into the next human, mosquito bites. But even within a given species that some mosquitoes carry malaria. The researchers suspected that differences in immune mosquito proteins might be responsible.
mosquitoes To identify these proteins, molecular biologists Mike Osta, George Christophides and Fotis Kafatos of the European Molecular Biology Laboratory in Heidelberg, Germany, engineering to miss certain immune genes. One at a time, they inactivated 100 of these genes using RNA strands that block a specific gene to its corresponding protein. A week later, they let the modified mosquitoes feed on infected mice with a parasite malaria line that has been genetically modified to glow green when alive, but turn black after death. Then they killed the mosquitoes, dissected their guts, and counted the living and dead parasites under a microscope.
Silencing a gene called LRIM1 more than tripled the number of live parasites, the researchers report in March 26 number science . This suggests that the gene normally helps kill insects Plasmodium . In contrast, silencing one of two other genes, CTL4 and CTLMA2 has caused mosquitoes to kill many more parasites than usual, suggesting that proteins they are somehow protecting Plasmodium . If the results are valid for the parasite of human malaria, chemicals that block or stimulate two protective genes the parasite killing gene could slow the spread of malaria, said Osta.
"It's impressive work," parasitologist said Kim Williamson of Loyola University of Chicago, but there is a long way to go before that wild mosquitoes can be controlled in this way;. For example, researchers must show that the three genes controlling resistance to Plasmodium species that infects humans. However, the approach is promising, she said, because when it is to infect mosquitoes, "the parasite is relatively vulnerable."
Related Sites
Kafatos lab
Background of the malaria life cycle
background on the WHO malaria
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