Sunday, October 30, 2011
Deadly Parasite juggles the number of its Chromosomes
Scientists have discovered a medicine-resistant parasite that has a copy number of chromosome that varies among individuals. While chromosomes almost always occur in pairs, the Leishmania parasite can reportedly have up to five copies of certain chromosomes. The "chromosome juggling" Leishmania parasite is transmitted by mosquito bites, and causes a disease called leishmaniasis, which accounts for 50,000 annual deaths worldwide.
Researchers gained in interest in the Leishmania parasite when they discovered that genetically similar specimens of the parasite responded very differently to the same medicine. Using next generation sequencing, researchers genotyped the entire genome of seventeen different strands of the Leishmania parasite. They hoped that they would find SNPs that explained the way that the parasite reacted differently to the same medicine. Instead, the researchers discovered that all of the Leishmania parasite strains had a different, unnatural number of chromosomes. It is believed that the "chromosome juggling" is a method the parasite uses to fight drugs and the human immune system. The Leishmania parasite is the only known organism to behave in this manner.
The original article can be found here.