Study suggests that when it comes to malaria parasites, females are the weakest link

Disease causing organisms are notorious for their rapid evolution and their quick aquisition of resistance to the drugs used to fight them. However, in the case of the disease causing parasites Plasmodium, scientists have shown that it is the males of the species that really race ahead in the evolutionary race.

Sex is a key driver for evolution but this tends to be overlooked when looking at unicellular life forms, said Sarah Reece of Edinburgh University and her colleagues in their paper. The Plasmodium parasite, unlike humans, for example, does not have different genes coding for different sexes. Instead, sex is solely determined by which genes are expressed. Reece and colleagues placed the parasites under evolutionary pressure and observed that it was the male-biased genes that were the fast adaptors. The finding suggests that to help prevent resistance, new antimalarials should target the slower evolving female genes, or those that are expressed by both sexes.