Submitted by Livia Harriman on Wed, 05/03/2025 - 11:22
Malaria is one of the world’s deadliest infectious diseases, caused by tiny parasites of the Plasmodium genus.
While much research focuses on how to kill these parasites, scientists are still uncovering their unique biology. A recent study has revealed surprising details about how Plasmodium parasites replicate their DNA, findings that could have significant implications for developing new antimalarial drugs.
The Curious Case of Plasmodium DNA
Plasmodium parasites have an unusual trait: their DNA is incredibly rich in adenine (A) and thymine (T) bases, making up more than 80% of their genetic material in some species. This is a striking contrast to human DNA, which has a more balanced mix of all four bases (A, T, cytosine (C), and guanine (G)). Scientists have long wondered how this extreme DNA composition affects the parasite’s ability to grow and divide.
A Tale of Two Parasites
Researchers compared DNA replication in two species of malaria parasites: Plasmodium falciparum, which has a highly A/T-rich genome, and Plasmodium knowlesi, which has a more balanced DNA composition. They found that the differences in DNA content significantly affect how these parasites copy their genetic material.
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In P. falciparum, DNA replication occurs at a much slower pace compared to P. knowlesi.
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Instead of speeding up as replication progresses (as seen in human cells and P. knowlesi), P. falciparum's replication actually slows down over time.
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In P. knowlesi, certain high-A/T regions cause replication to slow down—but in P. falciparum, the entire replication process is slow, suggesting its molecular machinery has evolved to handle extreme A/T bias.
Why Does This Matter?
Many antimalarial drugs work by targeting DNA replication. The fact that P. falciparum already struggles with slow and inefficient replication suggests that it might be particularly vulnerable to drugs that disrupt this process. If scientists can develop treatments that further stall DNA replication in these parasites, they could create more effective and long-lasting antimalarial therapies.
Looking Ahead
This study opens the door for future research into how DNA replication speed influences parasite survival and drug resistance. By understanding the unique biology of malaria parasites at a molecular level, researchers can design treatments that exploit these weaknesses—bringing us one step closer to better ways to combat malaria.
Read the Full Study
For those interested in the details, the full study is available in Nucleic Acids Research: https://doi.org/10.1093/nar/gkaf111.
This study was a collaboration between the Merrick and Boemo Research Groups.