Featured Research

from universities, journals, and other organizations

African Thicket Rat Malaria Linked To Virulent Human Form

Date:
January 5, 2009
Source:
American Museum of Natural History
Summary:
Malarial parasites found in tree-dwelling African thicket rats share a close evolutionary relationship with Plasmodium falciparum and P. reichenowi. The analysis is based on amplification of entire mitochondrial genomes of malarial parasites that use humans, rodents, birds and lizards as their hosts.

Pictured is the malarial parasite Plasmodium berghei, which is found in African thicket rats.
Credit: Copyright CJ Janse

Even though the most deadly form of malaria for humans, Plasmodium falciparum, has been linked to malaria found in chimpanzees, this group has been fairly isolated on the malarial family tree—until now. A new phylogenetic analysis from the Sackler Institute for Comparative Genomics at the American Museum of Natural History reveals that malarial parasites found in tree-dwelling rats share a close evolutionary relationship with P. falciparum and Plasmodium reichenowi.

The analysis is based on amplification of entire mitochondrial genomes of malarial parasites that use humans, rodents, birds, and lizards as their hosts.

"This is the first time that a relationship has been found between human and rodent malaria," says Susan Perkins, Assistant Curator of Invertebrate Zoology at the Museum. "In all past studies, P. falciparum seemed to not be closely related to anything else but the chimpanzee parasite. But this study places it in a sister group of parasites from rodents."

The maternally inherited mitochondria of Plasmodium are among the smallest known in eukaryotes, containing only three protein-coding genes and a total of only about 6,000 nucleotides (the mitochondrial genomes of human and other animals are about 16,000 bases). The genome is also unusual because of its organization into linear, tandemly repeated DNA. These features allowed Perkins to take the unusual step of amplifying the entire genome in a single piece via polymerase chain reaction (PCR) and then sequence it to reconstruct the whole genome. The analysis that produced the phylogenetic tree was based on the sequences of the three protein-coding genes (a total of about 3,300 DNA characters).

The results place the malarial parasites found in African thicket rats, P. chabaudi, P. berghei,, and P. yoelii,, as a sister group of human and chimpanzee P. falciparum, and P. reichenowi,. This is interesting and surprising because the parasite found in African thicket rats—the only malarial parasite to be discovered first in mosquitoes and only later in a vertebrate host—is the most common laboratory model for human malarial research. The ,P. falciparum,-rodent group is most closely related to malarial parasites that infect humans and primates in Asia and other primates in Africa. The other clades defined by this new evolutionary tree follow previously determined evolutionary trees for malaria-causing parasites, published earlier this year by Perkins and colleagues at the University of Vermont. These other phylogenies were based on both mitochondrial and nuclear DNA.

"The link between human malaria and rodent malaria is exciting because, if they really are that closely related, our laboratory models might be more powerful for helping to study how to fight the disease," says Perkins. She also believes that this link may include more than these species: as-yet unpublished data collected earlier in her lab found a closely related form of ,Plasmodium, in bats from the same area, and it may be that the most virulent form of malaria jumped into humans from these other arboreal animals. "Like Ebola and SARS, this could be another example of bat-human linkage. Although the results of this study are unambiguous, they are nonetheless still based on just a very small portion of the parasite's entire DNA."

The new paper is published in the early online edition of Mitochondrial DNA, and the research was funded by the American Museum of Natural History with some computational work done at the Computational Biology Service Unit from Cornell University.


Story Source:

The above story is based on materials provided by American Museum of Natural History. Note: Materials may be edited for content and length.


Cite This Page:

American Museum of Natural History. "African Thicket Rat Malaria Linked To Virulent Human Form." ScienceDaily. ScienceDaily, 5 January 2009. <www.sciencedaily.com/releases/2008/12/081222122607.htm>.
American Museum of Natural History. (2009, January 5). African Thicket Rat Malaria Linked To Virulent Human Form. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2008/12/081222122607.htm
American Museum of Natural History. "African Thicket Rat Malaria Linked To Virulent Human Form." ScienceDaily. www.sciencedaily.com/releases/2008/12/081222122607.htm (accessed October 1, 2014).

Share This



More Fossils & Ruins News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Battle of New Orleans Cannon Gets New Carriage

Battle of New Orleans Cannon Gets New Carriage

AP (Sep. 30, 2014) A Spanish cannon used in the Battle of New Orleans and weighing nearly 3 tons was lowered Tuesday by pulleys, chains and muscle onto a new gun carriage like one that might have held it once aboard a navy ship. (Sept. 30) Video provided by AP
Powered by NewsLook.com
2,000 Year Old Pre-Inca Cloak on Display in Lima

2,000 Year Old Pre-Inca Cloak on Display in Lima

AFP (Sep. 27, 2014) A 2,000 year-old Pre-Inca cloak that is believed to represent an agricultural calendar of the Paracas culture is on display in Lima. Duration: 00:39 Video provided by AFP
Powered by NewsLook.com
Original Mozart Sonata Manuscript Found in Budapest

Original Mozart Sonata Manuscript Found in Budapest

AFP (Sep. 26, 2014) Considered lost for over two centuries, the original manuscript of one of the most famous works of Mozart's Sonata in A major has been uncovered in a library in Budapest. Duration: 01:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins