Parasitism

Hybrid protein offers malaria protection

Plasmodium falciparum
HACK THE ATTACK A malaria parasite Plasmodium falciparum is expert at invading red blood cells (shown in this colored TEM image). But a hybrid protein that spans the red blood cell membrane can thwart an attack, a new study found.

Dogged genetic detective work has led scientists to a hybrid red blood cell protein that offers some protection against malaria.

Reporting online May 18 in Science, researchers describe a genetic variant that apparently is responsible for the fusion of two proteins that protrude from the membranes of red blood cells. In its hybrid form, the protein somehow makes it more difficult for the malaria parasite to invade the blood cells.

Successful invasion by the parasite can cause flulike illness, and in severe cases, death. In 2015, 212 million cases of malaria occurred worldwide, according to the World Health Organization, and 429,000 people died, mostly young children.

People carrying the protective genetic variant are 30 to 50 percent less likely to develop severe malaria than those without, the researchers report. The genetic change was found largely in people from Kenya, Malawi and Tanzania, suggesting that it occurred relatively recently in East Africa.

Discovering any genetic changes that protect against malaria is of great interest, says hematologist and malaria specialist Dave Roberts of the University of Oxford, who was not involved with the study. Understanding such changes, he says, “may help us understand the pathological pathways by which the parasite causes so much disease.”

Previous research had hinted that genetic changes to a particular stretch of DNA on chromosome 4 offered some protection against malaria. But the research team, an international collaboration that included researchers and clinicians from across Africa, had to do substantial legwork spanning 10 years to unmask the changes. Databases that gather the genetic instruction books, or genomes, of individuals are biased toward European populations, while African samples are underrepresented. And human genetic diversity is particularly high in sub-Saharan Africa, so genomes with rare genetic changes can be easily missed.

What Gives Rise to Authoritarian Governments? Parasites, Study Says

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The psychological threat of parasites could give rise to authoritarian governments, according to a growing body of radical and controversial research.

When people try to explain the causes of authoritarianism, they often point to exploitable natural resources, economic inequality, lack of culture, or the ramifications of colonial withdrawal. But ever since the parasite-stress theory was developed in the early 2000s, these explanations have seemed incomplete.

The parasite-stress theory claims that people who develop in parasite-infested areas think and behave differently in order to avoid infection. They tend to be less open to strangers, less exploratory, and less curious – traits that contradict “progressive values,” as Peter Frost points out.

In 2013, biologists conducted a study based on the parasite-stress theory that examined the relationship between the prevalence of parasites (defined as any pathogenic organism) and authoritarianism in countries. The study authors explained their reasoning:

“Because many disease-causing parasites are invisible, and their actions mysterious, disease control has historically depended substantially on adherence to ritualized behavioral practices that reduced infection risk. Individuals who openly dissented from, or simply failed to conform to, these behavioral traditions therefore posed a health threat to self and others.”

(Photo: Getty Images)

The authors said that authoritarian tendencies in individuals serve a self-protective function, and these tendencies can temporarily increase

Parasite Living Inside Fish Eyeball Controls Its Behavior

In case you need a little more nightmare fuel, scientists have been studying a fish eyeball parasite. Diplostomum pseudospathaceum infects a fish’s eye as a larva. While the larva grows, it causes the fish to swim slower than usual, which protects both the fish and the parasite from predators. But when the larva is mature, it makes the fish swim faster and closer to the water’s surface. That’s so the fish will be eaten by a bird!

The eye fluke Diplostomum pseudospathaceum has a…