The Apicomplexan Genomic Landscape - The Evolutionary Context of Plasmodium
Jeremy DeBarry, Segun Fatumo and Jessica C. Kissinger
from: Malaria Parasites: Comparative Genomics, Evolution and Molecular Biology (Edited by: Jane M. Carlton, Susan L. Perkins and Kirk W. Deitsch). Caister Academic Press, U.K. (2013)
Abstract
The apicomplexan genome is quite different from the typical eukaryotic genome that graces our textbooks and the majority of literature on the topic. It is small (8.5 - 63 Mb), compact, nearly devoid of transposable elements, and lacking any significant synteny outside of genus- and in some cases, family-level classifications. The nuclear genome has experienced significant gene loss, a characteristic of parasitic organisms. Numerous genes have entered the nuclear genome via de novo creation (through recombination, accumulated mutation or gene duplication and subsequent divergence), intracellular gene transfer from organellar and algal endosymbiont genomes and lateral gene transfer from bacteria and elsewhere. Nuclear genome data are currently available for 18 species within 8 genera; namely Cryptosporidium, Eimeria, Sarcocystis, Neospora, Toxoplasma, Babesia, Theileria and Plasmodium. Analyses have revealed dynamic genomes that share a remarkably small percentage of "core" genes comprising 11-23% of total gene content, plus large repertoires of lineage- and species-specific genes. Chromosome number and the organization of genes and other genomic features along the chromosome vary across the phylum. Plasmodium, the causative agent of malaria, is typical in that genomes from the same genus are highly syntenic, but it differs in that subtelomeric regions host the majority of lineage- and species-specific genes. Tools to perform comparative analyses within Plasmodium and across the Apicomplexa are available at EuPathDB.org and other sites read more ...
