Complete avian malaria parasite genomes reveal features associated with lineage specific evolution in birds and mammals.
Böhme U., Otto TD., Cotton J., Steinbiss S., Sanders M., Oyola SO., Nicot A., Gandon S., Patra KP., Herd C., Bushell E., Modrzynska KK., Billker O., Vinetz JM., Rivero A., Newbold CI., Berriman M.
Avian malaria parasites are prevalent around the world, and infect a wide diversity of bird species. Here we report the sequencing and analysis of high quality draft genome sequences for two avian malaria species,Plasmodium relictumandPlasmodium gallinaceumWe identify 50 genes that are specific to avian malaria, located in an otherwise conserved core of the genome that shares gene synteny with all other sequenced malaria genomes. Phylogenetic analysis suggests that the avian malaria species form an outgroup to the mammalianPlasmodiumspecies and using amino acid divergence between species, we estimate the avian and mammalian-infective lineages diverged in the order of 10 million years ago. Consistent with their phylogenetic position, we identify orthologs of genes that had previously appeared to be restricted to the clades of parasites containingP. falciparumandP. vivaxthe species with the greatest impact on human health. From these orthologs, we explore differential diversifying selection across the genus and show that the avian lineage is remarkable in the extent to which invasion related genes are evolving. The subtelomeres of theP. relictumandP. gallinaceumgenomes contain several novel gene families, including an expandedsurfmultigene family. We also identify an expansion of reticulocyte binding protein homologs inP. relictumand within these proteins, we detect distinct regions that are specific to non-human primate, humans, rodent and avian hosts. For the first time in thePlasmodiumlineage we find evidence of transposable elements, including several hundred fragments of LTR-retrotransposons in both species and an apparently complete LTR-retrotransposon in the genome ofP. gallinaceum.