Genetic map: a new tool for malaria research

Scientists have successfully fabricated genome-scale maps of gene variation to find malaria parasites; This map initially decoded genes involved in drug resistance.

An international team of scientists has announced the completion of a large genome map that represents the genetic variation of human malaria parasites of the Plasmodium falciparum genus.

This study revealed a remarkable genetic variation in the genome of pathogens, including a first list of nearly 47,000 genetically distinct forms in the tested parasite animals. all over the world.

Life cycle of malaria parasites
(Photo: history.nih.gov)

These differences have laid the foundation for analyzing the functions of key genes of parasitic animals and for tracing the origins of malaria spread globally. Led by scientists at Harvard Medical School and the Institute Combining MIT and Harvard University, along with scientists in Senegal, the study discovered new genes. strange, genes that could be the cause of resistance to current medications.

'Malaria is still a major threat to the health of people around the world, partly because of genetic changes in malaria parasites that cause the disease,' said Dyann Wirth, teacher. Professor and Head of Immunology and Infectious Diseases at Harvard Medical School, the principal scientist who carried out the study, said. 'This study gives us one of the first glimpses of genetic variation in the entire genome of malaria parasites - an extremely important step in creating a comprehensive genetic research tool for with malaria researchers. '

Plasmodium falciparum malaria parasites - the deadliest parasite of four human malaria parasites - kills one person every 30 seconds, mostly children living in Africa. Despite decades of research, genetic changes that allow this parasite to escape the body's natural resistance and defeat antimalarial drugs are still a big mystery.

To get a general picture of genetic variation - in the world and in the genome - scientists analyzed more than 50 different P. falciparum parasites from different geographical locations. This analysis includes a complete sequencing of the two most well-studied parasite samples as well as extensive analysis of the DNA of 16 other isolated studied parasites.

The study is one of three large studies, the study of parasitic DNA, published in Nature Genetics. It shows a collaborative effort between Boston scientists and a group of scientists led by Souleymane Mboup - Mboup is a professor at Cheikh Anta Diop University in Senegal, where malaria is a circulating epidemic. .'We are very grateful for the contributions of our colleagues in Senegal. They are very important members in this collaboration. '

By comparing different DNA sequences and with the sequenced genome in 2002 of P. falciparum malaria parasites, scientists have discovered a large number of differences, including near 47,000 modified forms of single-celled genes are called single nucleotide polymorphisms (SNPs). This level is more than twice the level of thought of the parasite's DNA diversity. Although more SNPs can be found, this first survey - like the recent Human HapMap project - paved the way for future systematic efforts to identify the genes of the sign. Biology plays an important role in malaria.

'The role of most malaria parasite genes is still unknown,' said Sarah Volkman, a research scientist at Harvard University School of Medicine. 'An important application of this new tool is to identify genes that play a vital role in the development and spread of malaria.'

Parasite Plasmodium falciparum malaria(Photo: arstechnica.com)

One of the advantages of this device is its ability to identify differences between parasites. This information may help identify genes that cause malaria drug resistance - an important obstacle to good control of the disease. Using a genetic map to compare parasites exposed to various antimalarial drugs, scientists have identified a novel, regional gene region that is highly involved in resistance to pyrimethamine. , and also identified a region of the genome known to be resistant to chloroquine resistance.

'The same genetic principles used to study human evolution can provide important clues to malaria,' said Pardis Sabeti, postdoctoral fellow of the Combined Institute for know. 'This tool has brought a better understanding of genetic variation that correlates with different therapeutic drugs, helping us to identify genes that can contribute to drug resistance.

The gene map can also identify the genetic regions of different parasitic species . Applying it to parasites from different continents, scientists have discovered that the samples of P. falciparum malaria parasites in Africa have a much greater DNA variation than those of other parasites. Malaria parasite samples in Asia and America.

This understanding guides the selection of markers of gene identification to monitor the transmission of different parasites, particularly toxic or potentially resistant, parasites. This understanding also laid the foundation for linking parasitic genes with characteristics that change geographically and enhance the strong position of malaria in many parts of the world.

'Genome tools have been widely used in the world's leading diseases. This project underscores the power and importance of applying genome tools in devastating diseases in developing countries around the world, ' said Eric Lander, one of the authors of the research article, director of the Combined Institute said. 'By linking forces of scientists in the US, Africa and elsewhere, we can quickly know the genetic variation of malaria around the world. Knowing how an enemy will be is an extremely important step in fighting it back. '

Thanh Van