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 Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>