"It was particularly striking that most of the parasites that contained the duplicate gene came from areas where we see the population divided between Duffy-positive and Duffy-negative individuals," Serre said.
The researchers believe one possibility is that in such split populations, the Duffy-positive individuals keep parasites circulating in their communities, allowing them to frequently attempt to infect individuals who are Duffy-negative. Such repeated encounters, they say, increase the chances that a P. vivax parasite could develop a new way to penetrate red blood cells.
In Cambodia, Evidence of a New "Invasion Mechanism"
In the second study, the researchers analyzed the genome of a P. vivax parasite from Cambodia. They found a previously unknown gene that "harbors all the key features" of an "invasion protein" for gaining access to red blood cells. For example, the protein expressed by this gene is similar to proteins used by other Plasmodium parasites, including P. falciparum to cause infections.
Subsequent investigation found that this new gene is widely present in contemporary vivax parasites around the world, but with a notable exception: it is not found in the vivax parasite sequenced in 2008 that has been used by malaria scientists as the "reference" genome for studying the genetics of the parasite.
The ASTMH Annual Meeting is the premier international gathering for those working in malaria, note
|Contact: Preeti Singh