Malaria Parasites May Skew Sex Ratio To Survive

Plasmodium vivax parasites alter their sex ratios in response to treatment with chloroquine, study shows.

AsianScientist (Feb. 22, 2019) – Scientists in Cambodia and the US have found that not all malaria infections contain the same proportion of male and female parasites, with implications for the propagation of the disease by mosquitoes. They reported their findings in the journal Nature Communications.

The parasite Plasmodium vivax is responsible for the most widespread form of malaria in humans. It is transmitted by mosquitoes and causes more than 8.5 million clinical malaria cases worldwide, threatening more than two billion people in 90 countries. Unlike Plasmodium falciparum, another species of malaria, P. vivax cannot be cultured in vitro and remains poorly understood and resistant to elimination efforts.

Genome sequencing studies have provided unique insights on this neglected human parasite, but are limited to identifying biological differences encoded in DNA sequences. However, gene expression studies, which could provide information on the regulation of the parasite life cycle and its response to drugs, have been challenging to implement for P. vivax due to the heterogeneous mixture of parasite stages present in infected patients.

In this study, researchers led by Associate Professor David Serre at the Institute of Genome Sciences of the University of Maryland School of Medicine sought to better understand the transmission of P. vivax. Teaming up with scientists at the Institut Pasteur in Cambodia, they analyzed the parasite gene expression profiles from P. vivax malaria patients enrolled in a study to determine the effectiveness of chloroquine as a malaria treatment.

Using a combination of genomic and bioinformatic approaches, they compared the parasite transcriptomes from different patient infections and analyzed how the parasites responded to chloroquine, a common antimalarial drug.

“By analyzing the parasite mRNAs directly from infected patient blood samples, we were able to observe that not all infections contained the same proportion of the male and female parasites that are required for infecting mosquitoes and propagating the disease. This observation suggests that parasite transmission is more complex that we previously thought and, perhaps, that the parasite is able to modify its development to ensure optimal survival,” said Serre.

The researchers hope that their findings will help clinicians better understand how to treat, prevent and ultimately eliminate P. vivax, especially amid growing concerns of drug resistance to antimalarial treatments.

The article can be found at: Kim et al. (2019) Plasmodium vivax Transcriptomes Reveal Stage-specific Chloroquine Response and Differential Regulation of Male and Female Gametocytes.


Source: University of Maryland; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Related Stories from Asian Scientist