Phylogenetic analysis indicates bacteria-to-apicoplast lateral gene transfer.

Apicomplexan protozoa contains a highly reduced plastid-like organelle termed apicoplast. Data from clpC gene in apicoplast and their homologs in other plastids and bacteria were used to reconstruct phylogeny of apicoplast. Trees were reconstructed using neighbor-joining, minimum evolution, maximum parsimony and maximum likelihood. The reconstructions robustly support the monophyly of apicoplast and B. burgdorferi. This result underpins the mixture-genome hypotheses of apicoplast, furthermore, provides a new insight into the origin of this mixture genome.