Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Genetic map offers new tool for malaria research

12.12.2006
Scientists create genome-scale map of genetic variation for malaria parasite; initial use unlocks genes involved in drug resistance

An international research team announced today the completion of a genome-wide map that charts the genetic variability of the human malaria parasite Plasmodium falciparum. Published in the December 10 advance online edition of Nature Genetics, the study reveals striking variation within the pathogen's genome, including an initial catalog of nearly 47,000 specific genetic differences among parasites sampled worldwide. These differences lay the foundation for dissecting the functions of important parasite genes and for tracing the global spread of malaria. Led by scientists at the Harvard School of Public Health and the Broad Institute of MIT and Harvard, together with researchers in Senegal, the work has already unearthed novel genes that may underlie resistance to current drugs against the disease.

"Malaria remains a significant threat to global public health, driven in part by the genetic changes in the parasite that causes the disease," said senior author Dyann Wirth, a professor and chairman of the department of immunology and infectious diseases at the Harvard School of Public Health and the co-director of the Broad Institute's Infectious Disease Initiative. "This study gives us one of the first looks at genetic variation across the entire malaria parasite genome — a critical step toward a comprehensive genetic tool for the malaria research community."

Plasmodium falciparum — the deadliest of the four parasites that cause malaria in humans — kills one person every 30 seconds, mostly children living in Africa. Despite decades of research, the genetic changes that enable it to escape the body's natural defenses and to overcome malaria drugs remain largely unknown.

To gain a broad picture of genetic variability — worldwide and genome-wide — the scientists analyzed more than 50 different P. falciparum samples from diverse geographic locations. This includes the complete genome sequencing of two well-studied samples as well as extensive DNA analyses of 16 additional isolates. The work is one of three large-scale studies of the parasite's DNA that appear together in Nature Genetics, and it represents a collaborative effort among Boston area researchers and a scientific team led by Souleymane Mboup, a professor at the Cheikh Anta Diop University in Senegal where malaria is endemic. "We are grateful for the contributions of our colleagues in Senegal. They are a crucial part of this collaboration," said Wirth.

By comparing the DNA sequences to each other and to the P. falciparum genome sequenced in 2002, the researchers uncovered extensive differences, including ~ 47,000 single letter changes called single nucleotide polymorphisms (SNPs). This represents more than double the expected level of diversity in the parasite's DNA. Although there are probably many more SNPs to be found, this initial survey — like the recent HapMap project in humans — provides a launching point for future systematic efforts to identify parasite genes that are essential to malaria.

"The roles of most of the malaria parasite's genes are still not known," said first author Sarah Volkman, a research scientist at the Harvard School of Public Health. "An important application of this new tool will be in pinpointing the genes that are vital to the development and spread of malaria."

One of the tool's strengths is its ability to reveal evolutionary differences among parasites. This information can shed light on the genes responsible for malaria drug resistance — a major obstacle to adequate control of the disease. Using the genetic map to compare parasites exposed to different anti-malarial drugs, the scientists identified a novel region that is strongly implicated in resistance to the drug pyrimethamine, and also confirmed a region of the genome known to be involved in chloroquine drug resistance.

"The same genetic principles used to study human evolution can provide important clues about malaria," said first author Pardis Sabeti, a postdoctoral fellow at the Broad Institute. "This tool has already yielded insights into the genetic changes that correlate with different drug treatments, pointing us to genes that may contribute to drug resistance."

The map can also define the genetic landscapes of different parasite populations. Applying it to parasites from various continents, the scientists discovered greater DNA variability among P. falciparum samples from Africa relative to those from Asia and the Americas. This knowledge guides the selection of genetic markers to track the transmission of distinct parasites, particularly ones that are virulent or drug resistant. It also lays the groundwork for connecting parasite genes with traits that vary geographically and bolster malaria's foothold in many parts of the world.

"Genomic tools have largely been applied to first-world diseases up to now. This project underscores the power and importance of applying them to the devastating diseases of the developing world," said Eric Lander, one of the study's authors and the director of the Broad Institute. "By joining forces among scientists in the U.S., Africa and elsewhere, it should be possible to rapidly reveal the genetic variation in malaria around the world. Knowing the enemy will be a crucial step in fighting it."

Nicole Davis | EurekAlert!
Further information:
http://www.broad.mit.edu
http://www.plasmodb.org

Further reports about: Broad Institute DNA Malaria Universität Harvard parasite

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>