Genome Information

Referred to 3D7 strains of P.falciparum that has been mapped as reference genome, P.falciparum has 23Mb of 14 chromosomes that high AT content. The chromosomes are haploid throughout majority of its life cycle in human, and distributed among sequencing centers.

P.falciparum also has 5.9kb of mitochodrial DNA and 35kb of plastid-like circular DNA. By analysing mitochodrial DNA sequence polymorphism of P.falciparum, we are able to know its origin and geographical spread. A research by Conway et al. (2000) shown that P. falciparum originated in Africa and colonised Southeast Asia and South America separately by mitochondrial DNA analysis. While the plastid-like DNA molecule, it encoding almost exclusively components involved in gene expression. Other parasitic protists of the Phylum Apicomplexa also have a plastid-like genome with less sequence complexity.

Other than 3D7 strain, so far already 11 other strains of genome are sequenced by Broad Institute of MIT and Harvard in order to enable comparative genome studies. For example, among P.falciparum strains, P.falciparum Dd2 has a high tendency to acquire drug resistance, thus it is used to genetically map drug-resistance determinants by means of microsatellite markers. This comparative study of similarities and differences in genome between strains of P.falciparum enable studies to formulate effective antimalarial drugs and vaccines using gene or siRNA (short interfering RNA) etc. in order to eradicate Malaria globally.

There are several Plasmodium species that closely related to P.falciparum which are Plasmodium reichenowi, Plasmodium gallinaceu, and Plasmodium berghei. Although these species don’t infect human, they are served as a relevant model organism to study and define the genetic pathways involved in parasite development. Their genome data also useful for malaria vaccine development.